Imported from /home/lorry/working-area/delta_bmake-tarball/bmake.tar.gz.HEADbmakemaster

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+/*	$NetBSD: job.c,v 1.172 2013/03/05 22:01:43 christos Exp $	*/
+
+/*
+ * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Adam de Boor.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Copyright (c) 1988, 1989 by Adam de Boor
+ * Copyright (c) 1989 by Berkeley Softworks
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Adam de Boor.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef MAKE_NATIVE
+static char rcsid[] = "$NetBSD: job.c,v 1.172 2013/03/05 22:01:43 christos Exp $";
+#else
+#include <sys/cdefs.h>
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#)job.c	8.2 (Berkeley) 3/19/94";
+#else
+__RCSID("$NetBSD: job.c,v 1.172 2013/03/05 22:01:43 christos Exp $");
+#endif
+#endif /* not lint */
+#endif
+
+/*-
+ * job.c --
+ *	handle the creation etc. of our child processes.
+ *
+ * Interface:
+ *	Job_Make  	    	Start the creation of the given target.
+ *
+ *	Job_CatchChildren   	Check for and handle the termination of any
+ *	    	  	    	children. This must be called reasonably
+ *	    	  	    	frequently to keep the whole make going at
+ *	    	  	    	a decent clip, since job table entries aren't
+ *	    	  	    	removed until their process is caught this way.
+ *
+ *	Job_CatchOutput	    	Print any output our children have produced.
+ *	    	  	    	Should also be called fairly frequently to
+ *	    	  	    	keep the user informed of what's going on.
+ *	    	  	    	If no output is waiting, it will block for
+ *	    	  	    	a time given by the SEL_* constants, below,
+ *	    	  	    	or until output is ready.
+ *
+ *	Job_Init  	    	Called to intialize this module. in addition,
+ *	    	  	    	any commands attached to the .BEGIN target
+ *	    	  	    	are executed before this function returns.
+ *	    	  	    	Hence, the makefile must have been parsed
+ *	    	  	    	before this function is called.
+ *
+ *	Job_End  	    	Cleanup any memory used.
+ *
+ *	Job_ParseShell	    	Given the line following a .SHELL target, parse
+ *	    	  	    	the line as a shell specification. Returns
+ *	    	  	    	FAILURE if the spec was incorrect.
+ *
+ *	Job_Finish	    	Perform any final processing which needs doing.
+ *	    	  	    	This includes the execution of any commands
+ *	    	  	    	which have been/were attached to the .END
+ *	    	  	    	target. It should only be called when the
+ *	    	  	    	job table is empty.
+ *
+ *	Job_AbortAll	    	Abort all currently running jobs. It doesn't
+ *	    	  	    	handle output or do anything for the jobs,
+ *	    	  	    	just kills them. It should only be called in
+ *	    	  	    	an emergency, as it were.
+ *
+ *	Job_CheckCommands   	Verify that the commands for a target are
+ *	    	  	    	ok. Provide them if necessary and possible.
+ *
+ *	Job_Touch 	    	Update a target without really updating it.
+ *
+ *	Job_Wait  	    	Wait for all currently-running jobs to finish.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/file.h>
+#include <sys/time.h>
+#include "wait.h"
+
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#if !defined(USE_SELECT) && defined(HAVE_POLL_H)
+#include <poll.h>
+#else
+#ifndef USE_SELECT			/* no poll.h */
+# define USE_SELECT
+#endif
+#if defined(HAVE_SYS_SELECT_H)
+# include <sys/select.h>
+#endif
+#endif
+#include <signal.h>
+#include <stdio.h>
+#include <string.h>
+#include <utime.h>
+#if defined(HAVE_SYS_SOCKET_H)
+# include <sys/socket.h>
+#endif
+
+#include "make.h"
+#include "hash.h"
+#include "dir.h"
+#include "job.h"
+#include "pathnames.h"
+#include "trace.h"
+# define STATIC static
+
+/*
+ * error handling variables
+ */
+static int     	errors = 0;	    /* number of errors reported */
+static int    	aborting = 0;	    /* why is the make aborting? */
+#define ABORT_ERROR	1   	    /* Because of an error */
+#define ABORT_INTERRUPT	2   	    /* Because it was interrupted */
+#define ABORT_WAIT	3   	    /* Waiting for jobs to finish */
+#define JOB_TOKENS	"+EI+"	    /* Token to requeue for each abort state */
+
+/*
+ * this tracks the number of tokens currently "out" to build jobs.
+ */
+int jobTokensRunning = 0;
+int not_parallel = 0;		    /* set if .NOT_PARALLEL */
+
+/*
+ * XXX: Avoid SunOS bug... FILENO() is fp->_file, and file
+ * is a char! So when we go above 127 we turn negative!
+ */
+#define FILENO(a) ((unsigned) fileno(a))
+
+/*
+ * post-make command processing. The node postCommands is really just the
+ * .END target but we keep it around to avoid having to search for it
+ * all the time.
+ */
+static GNode   	  *postCommands = NULL;
+				    /* node containing commands to execute when
+				     * everything else is done */
+static int     	  numCommands; 	    /* The number of commands actually printed
+				     * for a target. Should this number be
+				     * 0, no shell will be executed. */
+
+/*
+ * Return values from JobStart.
+ */
+#define JOB_RUNNING	0   	/* Job is running */
+#define JOB_ERROR 	1   	/* Error in starting the job */
+#define JOB_FINISHED	2   	/* The job is already finished */
+
+/*
+ * Descriptions for various shells.
+ *
+ * The build environment may set DEFSHELL_INDEX to one of
+ * DEFSHELL_INDEX_SH, DEFSHELL_INDEX_KSH, or DEFSHELL_INDEX_CSH, to
+ * select one of the prefedined shells as the default shell.
+ *
+ * Alternatively, the build environment may set DEFSHELL_CUSTOM to the
+ * name or the full path of a sh-compatible shell, which will be used as
+ * the default shell.
+ *
+ * ".SHELL" lines in Makefiles can choose the default shell from the
+ # set defined here, or add additional shells.
+ */
+
+#ifdef DEFSHELL_CUSTOM
+#define DEFSHELL_INDEX_CUSTOM 0
+#define DEFSHELL_INDEX_SH     1
+#define DEFSHELL_INDEX_KSH    2
+#define DEFSHELL_INDEX_CSH    3
+#else /* !DEFSHELL_CUSTOM */
+#define DEFSHELL_INDEX_SH     0
+#define DEFSHELL_INDEX_KSH    1
+#define DEFSHELL_INDEX_CSH    2
+#endif /* !DEFSHELL_CUSTOM */
+
+#ifndef DEFSHELL_INDEX
+#define DEFSHELL_INDEX 0	/* DEFSHELL_INDEX_CUSTOM or DEFSHELL_INDEX_SH */
+#endif /* !DEFSHELL_INDEX */
+
+static Shell    shells[] = {
+#ifdef DEFSHELL_CUSTOM
+    /*
+     * An sh-compatible shell with a non-standard name.
+     *
+     * Keep this in sync with the "sh" description below, but avoid
+     * non-portable features that might not be supplied by all
+     * sh-compatible shells.
+     */
+{
+    DEFSHELL_CUSTOM,
+    FALSE, "", "", "", 0,
+    FALSE, "echo \"%s\"\n", "%s\n", "{ %s \n} || exit $?\n", "'\n'", '#',
+    "",
+    "",
+},
+#endif /* DEFSHELL_CUSTOM */
+    /*
+     * SH description. Echo control is also possible and, under
+     * sun UNIX anyway, one can even control error checking.
+     */
+{
+    "sh",
+    FALSE, "", "", "", 0,
+    FALSE, "echo \"%s\"\n", "%s\n", "{ %s \n} || exit $?\n", "'\n'", '#',
+#if defined(MAKE_NATIVE) && defined(__NetBSD__)
+    "q",
+#else
+    "",
+#endif
+    "",
+},
+    /*
+     * KSH description. 
+     */
+{
+    "ksh",
+    TRUE, "set +v", "set -v", "set +v", 6,
+    FALSE, "echo \"%s\"\n", "%s\n", "{ %s \n} || exit $?\n", "'\n'", '#',
+    "v",
+    "",
+},
+    /*
+     * CSH description. The csh can do echo control by playing
+     * with the setting of the 'echo' shell variable. Sadly,
+     * however, it is unable to do error control nicely.
+     */
+{
+    "csh",
+    TRUE, "unset verbose", "set verbose", "unset verbose", 10,
+    FALSE, "echo \"%s\"\n", "csh -c \"%s || exit 0\"\n", "", "'\\\n'", '#',
+    "v", "e",
+},
+    /*
+     * UNKNOWN.
+     */
+{
+    NULL,
+    FALSE, NULL, NULL, NULL, 0,
+    FALSE, NULL, NULL, NULL, NULL, 0,
+    NULL, NULL,
+}
+};
+static Shell *commandShell = &shells[DEFSHELL_INDEX]; /* this is the shell to
+						   * which we pass all
+						   * commands in the Makefile.
+						   * It is set by the
+						   * Job_ParseShell function */
+const char *shellPath = NULL,		  	  /* full pathname of
+						   * executable image */
+           *shellName = NULL;		      	  /* last component of shell */
+static const char *shellArgv = NULL;		  /* Custom shell args */
+
+
+STATIC Job	*job_table;	/* The structures that describe them */
+STATIC Job	*job_table_end;	/* job_table + maxJobs */
+static int	wantToken;	/* we want a token */
+static int lurking_children = 0;
+static int make_suspended = 0;	/* non-zero if we've seen a SIGTSTP (etc) */
+
+/*
+ * Set of descriptors of pipes connected to
+ * the output channels of children
+ */
+static struct pollfd *fds = NULL;
+static Job **jobfds = NULL;
+static int nfds = 0;
+static void watchfd(Job *);
+static void clearfd(Job *);
+static int readyfd(Job *);
+
+STATIC GNode   	*lastNode;	/* The node for which output was most recently
+				 * produced. */
+static char *targPrefix = NULL; /* What we print at the start of TARG_FMT */
+static Job tokenWaitJob;	/* token wait pseudo-job */
+
+static Job childExitJob;	/* child exit pseudo-job */
+#define	CHILD_EXIT	"."
+#define	DO_JOB_RESUME	"R"
+
+#define TARG_FMT  "%s %s ---\n" /* Default format */
+#define MESSAGE(fp, gn) \
+	if (maxJobs != 1) \
+	    (void)fprintf(fp, TARG_FMT, targPrefix, gn->name)
+
+static sigset_t caught_signals;	/* Set of signals we handle */
+#if defined(SYSV)
+#define KILLPG(pid, sig)	kill(-(pid), (sig))
+#else
+#define KILLPG(pid, sig)	killpg((pid), (sig))
+#endif
+
+static void JobChildSig(int);
+static void JobContinueSig(int);
+static Job *JobFindPid(int, int, Boolean);
+static int JobPrintCommand(void *, void *);
+static int JobSaveCommand(void *, void *);
+static void JobClose(Job *);
+static void JobExec(Job *, char **);
+static void JobMakeArgv(Job *, char **);
+static int JobStart(GNode *, int);
+static char *JobOutput(Job *, char *, char *, int);
+static void JobDoOutput(Job *, Boolean);
+static Shell *JobMatchShell(const char *);
+static void JobInterrupt(int, int) MAKE_ATTR_DEAD;
+static void JobRestartJobs(void);
+static void JobTokenAdd(void);
+static void JobSigLock(sigset_t *);
+static void JobSigUnlock(sigset_t *);
+static void JobSigReset(void);
+
+const char *malloc_options="A";
+
+static void
+job_table_dump(const char *where)
+{
+    Job *job;
+
+    fprintf(debug_file, "job table @ %s\n", where);
+    for (job = job_table; job < job_table_end; job++) {
+	fprintf(debug_file, "job %d, status %d, flags %d, pid %d\n",
+	    (int)(job - job_table), job->job_state, job->flags, job->pid);
+    }
+}
+
+/*
+ * JobSigLock/JobSigUnlock
+ *
+ * Signal lock routines to get exclusive access. Currently used to
+ * protect `jobs' and `stoppedJobs' list manipulations.
+ */
+static void JobSigLock(sigset_t *omaskp)
+{
+	if (sigprocmask(SIG_BLOCK, &caught_signals, omaskp) != 0) {
+		Punt("JobSigLock: sigprocmask: %s", strerror(errno));
+		sigemptyset(omaskp);
+	}
+}
+
+static void JobSigUnlock(sigset_t *omaskp)
+{
+	(void)sigprocmask(SIG_SETMASK, omaskp, NULL);
+}
+
+static void
+JobCreatePipe(Job *job, int minfd)
+{
+    int i, fd;
+
+    if (pipe(job->jobPipe) == -1)
+	Punt("Cannot create pipe: %s", strerror(errno));
+
+    /* Set close-on-exec flag for both */
+    (void)fcntl(job->jobPipe[0], F_SETFD, 1);
+    (void)fcntl(job->jobPipe[1], F_SETFD, 1);
+
+    /*
+     * We mark the input side of the pipe non-blocking; we poll(2) the
+     * pipe when we're waiting for a job token, but we might lose the
+     * race for the token when a new one becomes available, so the read 
+     * from the pipe should not block.
+     */
+    fcntl(job->jobPipe[0], F_SETFL, 
+	fcntl(job->jobPipe[0], F_GETFL, 0) | O_NONBLOCK);
+
+    for (i = 0; i < 2; i++) {
+       /* Avoid using low numbered fds */
+       fd = fcntl(job->jobPipe[i], F_DUPFD, minfd);
+       if (fd != -1) {
+	   close(job->jobPipe[i]);
+	   job->jobPipe[i] = fd;
+       }
+    }
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * JobCondPassSig --
+ *	Pass a signal to a job
+ *
+ * Input:
+ *	signop		Signal to send it
+ *
+ * Side Effects:
+ *	None, except the job may bite it.
+ *
+ *-----------------------------------------------------------------------
+ */
+static void
+JobCondPassSig(int signo)
+{
+    Job *job;
+
+    if (DEBUG(JOB)) {
+	(void)fprintf(debug_file, "JobCondPassSig(%d) called.\n", signo);
+    }
+
+    for (job = job_table; job < job_table_end; job++) {
+	if (job->job_state != JOB_ST_RUNNING)
+	    continue;
+	if (DEBUG(JOB)) {
+	    (void)fprintf(debug_file,
+			   "JobCondPassSig passing signal %d to child %d.\n",
+			   signo, job->pid);
+	}
+	KILLPG(job->pid, signo);
+    }
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * JobChldSig --
+ *	SIGCHLD handler.
+ *
+ * Input:
+ *	signo		The signal number we've received
+ *
+ * Results:
+ *	None.
+ *
+ * Side Effects:
+ *	Sends a token on the child exit pipe to wake us up from
+ *	select()/poll().
+ *
+ *-----------------------------------------------------------------------
+ */
+static void
+JobChildSig(int signo MAKE_ATTR_UNUSED)
+{
+    while (write(childExitJob.outPipe, CHILD_EXIT, 1) == -1 && errno == EAGAIN)
+	continue;
+}
+
+
+/*-
+ *-----------------------------------------------------------------------
+ * JobContinueSig --
+ *	Resume all stopped jobs.
+ *
+ * Input:
+ *	signo		The signal number we've received
+ *
+ * Results:
+ *	None.
+ *
+ * Side Effects:
+ *	Jobs start running again.
+ *
+ *-----------------------------------------------------------------------
+ */
+static void
+JobContinueSig(int signo MAKE_ATTR_UNUSED)
+{
+    /*
+     * Defer sending to SIGCONT to our stopped children until we return
+     * from the signal handler.
+     */
+    while (write(childExitJob.outPipe, DO_JOB_RESUME, 1) == -1 &&
+	errno == EAGAIN)
+	continue;
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * JobPassSig --
+ *	Pass a signal on to all jobs, then resend to ourselves.
+ *
+ * Input:
+ *	signo		The signal number we've received
+ *
+ * Results:
+ *	None.
+ *
+ * Side Effects:
+ *	We die by the same signal.
+ *
+ *-----------------------------------------------------------------------
+ */
+MAKE_ATTR_DEAD static void
+JobPassSig_int(int signo)
+{
+    /* Run .INTERRUPT target then exit */
+    JobInterrupt(TRUE, signo);
+}
+
+MAKE_ATTR_DEAD static void
+JobPassSig_term(int signo)
+{
+    /* Dont run .INTERRUPT target then exit */
+    JobInterrupt(FALSE, signo);
+}
+
+static void
+JobPassSig_suspend(int signo)
+{
+    sigset_t nmask, omask;
+    struct sigaction act;
+
+    /* Suppress job started/continued messages */
+    make_suspended = 1;
+
+    /* Pass the signal onto every job */
+    JobCondPassSig(signo);
+
+    /*
+     * Send ourselves the signal now we've given the message to everyone else.
+     * Note we block everything else possible while we're getting the signal.
+     * This ensures that all our jobs get continued when we wake up before
+     * we take any other signal.
+     */
+    sigfillset(&nmask);
+    sigdelset(&nmask, signo);
+    (void)sigprocmask(SIG_SETMASK, &nmask, &omask);
+
+    act.sa_handler = SIG_DFL;
+    sigemptyset(&act.sa_mask);
+    act.sa_flags = 0;
+    (void)sigaction(signo, &act, NULL);
+
+    if (DEBUG(JOB)) {
+	(void)fprintf(debug_file,
+		       "JobPassSig passing signal %d to self.\n", signo);
+    }
+
+    (void)kill(getpid(), signo);
+
+    /*
+     * We've been continued.
+     *
+     * A whole host of signals continue to happen!
+     * SIGCHLD for any processes that actually suspended themselves.
+     * SIGCHLD for any processes that exited while we were alseep.
+     * The SIGCONT that actually caused us to wakeup.
+     *
+     * Since we defer passing the SIGCONT on to our children until
+     * the main processing loop, we can be sure that all the SIGCHLD
+     * events will have happened by then - and that the waitpid() will
+     * collect the child 'suspended' events.
+     * For correct sequencing we just need to ensure we process the
+     * waitpid() before passign on the SIGCONT.
+     *
+     * In any case nothing else is needed here.
+     */
+
+    /* Restore handler and signal mask */
+    act.sa_handler = JobPassSig_suspend;
+    (void)sigaction(signo, &act, NULL);
+    (void)sigprocmask(SIG_SETMASK, &omask, NULL);
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * JobFindPid  --
+ *	Compare the pid of the job with the given pid and return 0 if they
+ *	are equal. This function is called from Job_CatchChildren
+ *	to find the job descriptor of the finished job.
+ *
+ * Input:
+ *	job		job to examine
+ *	pid		process id desired
+ *
+ * Results:
+ *	Job with matching pid
+ *
+ * Side Effects:
+ *	None
+ *-----------------------------------------------------------------------
+ */
+static Job *
+JobFindPid(int pid, int status, Boolean isJobs)
+{
+    Job *job;
+
+    for (job = job_table; job < job_table_end; job++) {
+	if ((job->job_state == status) && job->pid == pid)
+	    return job;
+    }
+    if (DEBUG(JOB) && isJobs)
+	job_table_dump("no pid");
+    return NULL;
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * JobPrintCommand  --
+ *	Put out another command for the given job. If the command starts
+ *	with an @ or a - we process it specially. In the former case,
+ *	so long as the -s and -n flags weren't given to make, we stick
+ *	a shell-specific echoOff command in the script. In the latter,
+ *	we ignore errors for the entire job, unless the shell has error
+ *	control.
+ *	If the command is just "..." we take all future commands for this
+ *	job to be commands to be executed once the entire graph has been
+ *	made and return non-zero to signal that the end of the commands
+ *	was reached. These commands are later attached to the postCommands
+ *	node and executed by Job_End when all things are done.
+ *	This function is called from JobStart via Lst_ForEach.
+ *
+ * Input:
+ *	cmdp		command string to print
+ *	jobp		job for which to print it
+ *
+ * Results:
+ *	Always 0, unless the command was "..."
+ *
+ * Side Effects:
+ *	If the command begins with a '-' and the shell has no error control,
+ *	the JOB_IGNERR flag is set in the job descriptor.
+ *	If the command is "..." and we're not ignoring such things,
+ *	tailCmds is set to the successor node of the cmd.
+ *	numCommands is incremented if the command is actually printed.
+ *-----------------------------------------------------------------------
+ */
+static int
+JobPrintCommand(void *cmdp, void *jobp)
+{
+    Boolean	  noSpecials;	    /* true if we shouldn't worry about
+				     * inserting special commands into
+				     * the input stream. */
+    Boolean       shutUp = FALSE;   /* true if we put a no echo command
+				     * into the command file */
+    Boolean	  errOff = FALSE;   /* true if we turned error checking
+				     * off before printing the command
+				     * and need to turn it back on */
+    const char    *cmdTemplate;	    /* Template to use when printing the
+				     * command */
+    char    	  *cmdStart;	    /* Start of expanded command */
+    char	  *escCmd = NULL;    /* Command with quotes/backticks escaped */
+    char     	  *cmd = (char *)cmdp;
+    Job           *job = (Job *)jobp;
+    int           i, j;
+
+    noSpecials = NoExecute(job->node);
+
+    if (strcmp(cmd, "...") == 0) {
+	job->node->type |= OP_SAVE_CMDS;
+	if ((job->flags & JOB_IGNDOTS) == 0) {
+	    job->tailCmds = Lst_Succ(Lst_Member(job->node->commands,
+						cmd));
+	    return 1;
+	}
+	return 0;
+    }
+
+#define DBPRINTF(fmt, arg) if (DEBUG(JOB)) {	\
+	(void)fprintf(debug_file, fmt, arg); 	\
+    }						\
+   (void)fprintf(job->cmdFILE, fmt, arg);	\
+   (void)fflush(job->cmdFILE);
+
+    numCommands += 1;
+
+    cmdStart = cmd = Var_Subst(NULL, cmd, job->node, FALSE);
+
+    cmdTemplate = "%s\n";
+
+    /*
+     * Check for leading @' and -'s to control echoing and error checking.
+     */
+    while (*cmd == '@' || *cmd == '-' || (*cmd == '+')) {
+	switch (*cmd) {
+	case '@':
+	    shutUp = DEBUG(LOUD) ? FALSE : TRUE;
+	    break;
+	case '-':
+	    job->flags |= JOB_IGNERR;
+	    errOff = TRUE;
+	    break;
+	case '+':
+	    if (noSpecials) {
+		/*
+		 * We're not actually executing anything...
+		 * but this one needs to be - use compat mode just for it.
+		 */
+		CompatRunCommand(cmdp, job->node);
+		return 0;
+	    }
+	    break;
+	}
+	cmd++;
+    }
+
+    while (isspace((unsigned char) *cmd))
+	cmd++;
+
+    /*
+     * If the shell doesn't have error control the alternate echo'ing will
+     * be done (to avoid showing additional error checking code) 
+     * and this will need the characters '$ ` \ "' escaped
+     */
+
+    if (!commandShell->hasErrCtl) {
+	/* Worst that could happen is every char needs escaping. */
+	escCmd = bmake_malloc((strlen(cmd) * 2) + 1);
+	for (i = 0, j= 0; cmd[i] != '\0'; i++, j++) {
+		if (cmd[i] == '$' || cmd[i] == '`' || cmd[i] == '\\' || 
+			cmd[i] == '"')
+			escCmd[j++] = '\\';
+		escCmd[j] = cmd[i];	
+	}
+	escCmd[j] = 0;
+    }
+
+    if (shutUp) {
+	if (!(job->flags & JOB_SILENT) && !noSpecials &&
+	    commandShell->hasEchoCtl) {
+		DBPRINTF("%s\n", commandShell->echoOff);
+	} else {
+	    if (commandShell->hasErrCtl)
+		shutUp = FALSE;
+	}
+    }
+
+    if (errOff) {
+	if (!noSpecials) {
+	    if (commandShell->hasErrCtl) {
+		/*
+		 * we don't want the error-control commands showing
+		 * up either, so we turn off echoing while executing
+		 * them. We could put another field in the shell
+		 * structure to tell JobDoOutput to look for this
+		 * string too, but why make it any more complex than
+		 * it already is?
+		 */
+		if (!(job->flags & JOB_SILENT) && !shutUp &&
+		    commandShell->hasEchoCtl) {
+			DBPRINTF("%s\n", commandShell->echoOff);
+			DBPRINTF("%s\n", commandShell->ignErr);
+			DBPRINTF("%s\n", commandShell->echoOn);
+		} else {
+			DBPRINTF("%s\n", commandShell->ignErr);
+		}
+	    } else if (commandShell->ignErr &&
+		      (*commandShell->ignErr != '\0'))
+	    {
+		/*
+		 * The shell has no error control, so we need to be
+		 * weird to get it to ignore any errors from the command.
+		 * If echoing is turned on, we turn it off and use the
+		 * errCheck template to echo the command. Leave echoing
+		 * off so the user doesn't see the weirdness we go through
+		 * to ignore errors. Set cmdTemplate to use the weirdness
+		 * instead of the simple "%s\n" template.
+		 */
+		if (!(job->flags & JOB_SILENT) && !shutUp) {
+			if (commandShell->hasEchoCtl) {
+				DBPRINTF("%s\n", commandShell->echoOff);
+			}
+			DBPRINTF(commandShell->errCheck, escCmd);
+			shutUp = TRUE;
+		} else {
+			if (!shutUp) {
+				DBPRINTF(commandShell->errCheck, escCmd);
+			}
+		}
+		cmdTemplate = commandShell->ignErr;
+		/*
+		 * The error ignoration (hee hee) is already taken care
+		 * of by the ignErr template, so pretend error checking
+		 * is still on.
+		 */
+		errOff = FALSE;
+	    } else {
+		errOff = FALSE;
+	    }
+	} else {
+	    errOff = FALSE;
+	}
+    } else {
+
+	/* 
+	 * If errors are being checked and the shell doesn't have error control
+	 * but does supply an errOut template, then setup commands to run
+	 * through it.
+	 */
+
+	if (!commandShell->hasErrCtl && commandShell->errOut && 
+	    (*commandShell->errOut != '\0')) {
+		if (!(job->flags & JOB_SILENT) && !shutUp) {
+			if (commandShell->hasEchoCtl) {
+				DBPRINTF("%s\n", commandShell->echoOff);
+			}
+			DBPRINTF(commandShell->errCheck, escCmd);
+			shutUp = TRUE;
+		}
+		/* If it's a comment line or blank, treat as an ignored error */
+		if ((escCmd[0] == commandShell->commentChar) ||
+		    (escCmd[0] == 0))
+			cmdTemplate = commandShell->ignErr;
+		else
+			cmdTemplate = commandShell->errOut;
+		errOff = FALSE;
+	}
+    }
+
+    if (DEBUG(SHELL) && strcmp(shellName, "sh") == 0 &&
+	(job->flags & JOB_TRACED) == 0) {
+	    DBPRINTF("set -%s\n", "x");
+	    job->flags |= JOB_TRACED;
+    }
+    
+    DBPRINTF(cmdTemplate, cmd);
+    free(cmdStart);
+    if (escCmd)
+        free(escCmd);
+    if (errOff) {
+	/*
+	 * If echoing is already off, there's no point in issuing the
+	 * echoOff command. Otherwise we issue it and pretend it was on
+	 * for the whole command...
+	 */
+	if (!shutUp && !(job->flags & JOB_SILENT) && commandShell->hasEchoCtl){
+	    DBPRINTF("%s\n", commandShell->echoOff);
+	    shutUp = TRUE;
+	}
+	DBPRINTF("%s\n", commandShell->errCheck);
+    }
+    if (shutUp && commandShell->hasEchoCtl) {
+	DBPRINTF("%s\n", commandShell->echoOn);
+    }
+    return 0;
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * JobSaveCommand --
+ *	Save a command to be executed when everything else is done.
+ *	Callback function for JobFinish...
+ *
+ * Results:
+ *	Always returns 0
+ *
+ * Side Effects:
+ *	The command is tacked onto the end of postCommands's commands list.
+ *
+ *-----------------------------------------------------------------------
+ */
+static int
+JobSaveCommand(void *cmd, void *gn)
+{
+    cmd = Var_Subst(NULL, (char *)cmd, (GNode *)gn, FALSE);
+    (void)Lst_AtEnd(postCommands->commands, cmd);
+    return(0);
+}
+
+
+/*-
+ *-----------------------------------------------------------------------
+ * JobClose --
+ *	Called to close both input and output pipes when a job is finished.
+ *
+ * Results:
+ *	Nada
+ *
+ * Side Effects:
+ *	The file descriptors associated with the job are closed.
+ *
+ *-----------------------------------------------------------------------
+ */
+static void
+JobClose(Job *job)
+{
+    clearfd(job);
+    (void)close(job->outPipe);
+    job->outPipe = -1;
+
+    JobDoOutput(job, TRUE);
+    (void)close(job->inPipe);
+    job->inPipe = -1;
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * JobFinish  --
+ *	Do final processing for the given job including updating
+ *	parents and starting new jobs as available/necessary. Note
+ *	that we pay no attention to the JOB_IGNERR flag here.
+ *	This is because when we're called because of a noexecute flag
+ *	or something, jstat.w_status is 0 and when called from
+ *	Job_CatchChildren, the status is zeroed if it s/b ignored.
+ *
+ * Input:
+ *	job		job to finish
+ *	status		sub-why job went away
+ *
+ * Results:
+ *	None
+ *
+ * Side Effects:
+ *	Final commands for the job are placed on postCommands.
+ *
+ *	If we got an error and are aborting (aborting == ABORT_ERROR) and
+ *	the job list is now empty, we are done for the day.
+ *	If we recognized an error (errors !=0), we set the aborting flag
+ *	to ABORT_ERROR so no more jobs will be started.
+ *-----------------------------------------------------------------------
+ */
+/*ARGSUSED*/
+static void
+JobFinish (Job *job, WAIT_T status)
+{
+    Boolean 	 done, return_job_token;
+
+    if (DEBUG(JOB)) {
+	fprintf(debug_file, "Jobfinish: %d [%s], status %d\n",
+				job->pid, job->node->name, status);
+    }
+
+    if ((WIFEXITED(status) &&
+	 (((WEXITSTATUS(status) != 0) && !(job->flags & JOB_IGNERR)))) ||
+	WIFSIGNALED(status))
+    {
+	/*
+	 * If it exited non-zero and either we're doing things our
+	 * way or we're not ignoring errors, the job is finished.
+	 * Similarly, if the shell died because of a signal
+	 * the job is also finished. In these
+	 * cases, finish out the job's output before printing the exit
+	 * status...
+	 */
+	JobClose(job);
+	if (job->cmdFILE != NULL && job->cmdFILE != stdout) {
+	   (void)fclose(job->cmdFILE);
+	   job->cmdFILE = NULL;
+	}
+	done = TRUE;
+    } else if (WIFEXITED(status)) {
+	/*
+	 * Deal with ignored errors in -B mode. We need to print a message
+	 * telling of the ignored error as well as setting status.w_status
+	 * to 0 so the next command gets run. To do this, we set done to be
+	 * TRUE if in -B mode and the job exited non-zero.
+	 */
+	done = WEXITSTATUS(status) != 0;
+	/*
+	 * Old comment said: "Note we don't
+	 * want to close down any of the streams until we know we're at the
+	 * end."
+	 * But we do. Otherwise when are we going to print the rest of the
+	 * stuff?
+	 */
+	JobClose(job);
+    } else {
+	/*
+	 * No need to close things down or anything.
+	 */
+	done = FALSE;
+    }
+
+    if (done) {
+	if (WIFEXITED(status)) {
+	    if (DEBUG(JOB)) {
+		(void)fprintf(debug_file, "Process %d [%s] exited.\n",
+				job->pid, job->node->name);
+	    }
+	    if (WEXITSTATUS(status) != 0) {
+		if (job->node != lastNode) {
+		    MESSAGE(stdout, job->node);
+		    lastNode = job->node;
+		}
+#ifdef USE_META
+		if (useMeta) {
+		    meta_job_error(job, job->node, job->flags, WEXITSTATUS(status));
+		}
+#endif
+		(void)printf("*** [%s] Error code %d%s\n",
+				job->node->name,
+			       WEXITSTATUS(status),
+			       (job->flags & JOB_IGNERR) ? " (ignored)" : "");
+		if (job->flags & JOB_IGNERR) {
+		    WAIT_STATUS(status) = 0;
+		} else {
+		    PrintOnError(job->node, NULL);
+		}
+	    } else if (DEBUG(JOB)) {
+		if (job->node != lastNode) {
+		    MESSAGE(stdout, job->node);
+		    lastNode = job->node;
+		}
+		(void)printf("*** [%s] Completed successfully\n",
+				job->node->name);
+	    }
+	} else {
+	    if (job->node != lastNode) {
+		MESSAGE(stdout, job->node);
+		lastNode = job->node;
+	    }
+	    (void)printf("*** [%s] Signal %d\n",
+			job->node->name, WTERMSIG(status));
+	}
+	(void)fflush(stdout);
+    }
+
+#ifdef USE_META
+    if (useMeta) {
+	meta_job_finish(job);
+    }
+#endif
+    
+    return_job_token = FALSE;
+
+    Trace_Log(JOBEND, job);
+    if (!(job->flags & JOB_SPECIAL)) {
+	if ((WAIT_STATUS(status) != 0) ||
+		(aborting == ABORT_ERROR) ||
+		(aborting == ABORT_INTERRUPT))
+	    return_job_token = TRUE;
+    }
+
+    if ((aborting != ABORT_ERROR) && (aborting != ABORT_INTERRUPT) &&
+	(WAIT_STATUS(status) == 0)) {
+	/*
+	 * As long as we aren't aborting and the job didn't return a non-zero
+	 * status that we shouldn't ignore, we call Make_Update to update
+	 * the parents. In addition, any saved commands for the node are placed
+	 * on the .END target.
+	 */
+	if (job->tailCmds != NULL) {
+	    Lst_ForEachFrom(job->node->commands, job->tailCmds,
+			     JobSaveCommand,
+			    job->node);
+	}
+	job->node->made = MADE;
+	if (!(job->flags & JOB_SPECIAL))
+	    return_job_token = TRUE;
+	Make_Update(job->node);
+	job->job_state = JOB_ST_FREE;
+    } else if (WAIT_STATUS(status)) {
+	errors += 1;
+	job->job_state = JOB_ST_FREE;
+    }
+
+    /*
+     * Set aborting if any error.
+     */
+    if (errors && !keepgoing && (aborting != ABORT_INTERRUPT)) {
+	/*
+	 * If we found any errors in this batch of children and the -k flag
+	 * wasn't given, we set the aborting flag so no more jobs get
+	 * started.
+	 */
+	aborting = ABORT_ERROR;
+    }
+
+    if (return_job_token)
+	Job_TokenReturn();
+
+    if (aborting == ABORT_ERROR && jobTokensRunning == 0) {
+	/*
+	 * If we are aborting and the job table is now empty, we finish.
+	 */
+	Finish(errors);
+    }
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Job_Touch --
+ *	Touch the given target. Called by JobStart when the -t flag was
+ *	given
+ *
+ * Input:
+ *	gn		the node of the file to touch
+ *	silent		TRUE if should not print message
+ *
+ * Results:
+ *	None
+ *
+ * Side Effects:
+ *	The data modification of the file is changed. In addition, if the
+ *	file did not exist, it is created.
+ *-----------------------------------------------------------------------
+ */
+void
+Job_Touch(GNode *gn, Boolean silent)
+{
+    int		  streamID;   	/* ID of stream opened to do the touch */
+    struct utimbuf times;	/* Times for utime() call */
+
+    if (gn->type & (OP_JOIN|OP_USE|OP_USEBEFORE|OP_EXEC|OP_OPTIONAL|
+	OP_SPECIAL|OP_PHONY)) {
+	/*
+	 * .JOIN, .USE, .ZEROTIME and .OPTIONAL targets are "virtual" targets
+	 * and, as such, shouldn't really be created.
+	 */
+	return;
+    }
+
+    if (!silent || NoExecute(gn)) {
+	(void)fprintf(stdout, "touch %s\n", gn->name);
+	(void)fflush(stdout);
+    }
+
+    if (NoExecute(gn)) {
+	return;
+    }
+
+    if (gn->type & OP_ARCHV) {
+	Arch_Touch(gn);
+    } else if (gn->type & OP_LIB) {
+	Arch_TouchLib(gn);
+    } else {
+	char	*file = gn->path ? gn->path : gn->name;
+
+	times.actime = times.modtime = now;
+	if (utime(file, &times) < 0){
+	    streamID = open(file, O_RDWR | O_CREAT, 0666);
+
+	    if (streamID >= 0) {
+		char	c;
+
+		/*
+		 * Read and write a byte to the file to change the
+		 * modification time, then close the file.
+		 */
+		if (read(streamID, &c, 1) == 1) {
+		    (void)lseek(streamID, (off_t)0, SEEK_SET);
+		    while (write(streamID, &c, 1) == -1 && errno == EAGAIN)
+			continue;
+		}
+
+		(void)close(streamID);
+	    } else {
+		(void)fprintf(stdout, "*** couldn't touch %s: %s",
+			       file, strerror(errno));
+		(void)fflush(stdout);
+	    }
+	}
+    }
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Job_CheckCommands --
+ *	Make sure the given node has all the commands it needs.
+ *
+ * Input:
+ *	gn		The target whose commands need verifying
+ *	abortProc	Function to abort with message
+ *
+ * Results:
+ *	TRUE if the commands list is/was ok.
+ *
+ * Side Effects:
+ *	The node will have commands from the .DEFAULT rule added to it
+ *	if it needs them.
+ *-----------------------------------------------------------------------
+ */
+Boolean
+Job_CheckCommands(GNode *gn, void (*abortProc)(const char *, ...))
+{
+    if (OP_NOP(gn->type) && Lst_IsEmpty(gn->commands) &&
+	((gn->type & OP_LIB) == 0 || Lst_IsEmpty(gn->children))) {
+	/*
+	 * No commands. Look for .DEFAULT rule from which we might infer
+	 * commands
+	 */
+	if ((DEFAULT != NULL) && !Lst_IsEmpty(DEFAULT->commands) &&
+		(gn->type & OP_SPECIAL) == 0) {
+	    char *p1;
+	    /*
+	     * Make only looks for a .DEFAULT if the node was never the
+	     * target of an operator, so that's what we do too. If
+	     * a .DEFAULT was given, we substitute its commands for gn's
+	     * commands and set the IMPSRC variable to be the target's name
+	     * The DEFAULT node acts like a transformation rule, in that
+	     * gn also inherits any attributes or sources attached to
+	     * .DEFAULT itself.
+	     */
+	    Make_HandleUse(DEFAULT, gn);
+	    Var_Set(IMPSRC, Var_Value(TARGET, gn, &p1), gn, 0);
+	    if (p1)
+		free(p1);
+	} else if (Dir_MTime(gn, 0) == 0 && (gn->type & OP_SPECIAL) == 0) {
+	    /*
+	     * The node wasn't the target of an operator we have no .DEFAULT
+	     * rule to go on and the target doesn't already exist. There's
+	     * nothing more we can do for this branch. If the -k flag wasn't
+	     * given, we stop in our tracks, otherwise we just don't update
+	     * this node's parents so they never get examined.
+	     */
+	    static const char msg[] = ": don't know how to make";
+
+	    if (gn->flags & FROM_DEPEND) {
+		if (!Job_RunTarget(".STALE", gn->fname))
+		    fprintf(stdout, "%s: %s, %d: ignoring stale %s for %s\n",
+			progname, gn->fname, gn->lineno, makeDependfile,
+			gn->name);
+		return TRUE;
+	    }
+
+	    if (gn->type & OP_OPTIONAL) {
+		(void)fprintf(stdout, "%s%s %s (ignored)\n", progname,
+		    msg, gn->name);
+		(void)fflush(stdout);
+	    } else if (keepgoing) {
+		(void)fprintf(stdout, "%s%s %s (continuing)\n", progname,
+		    msg, gn->name);
+		(void)fflush(stdout);
+  		return FALSE;
+	    } else {
+		(*abortProc)("%s%s %s. Stop", progname, msg, gn->name);
+		return FALSE;
+	    }
+	}
+    }
+    return TRUE;
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * JobExec --
+ *	Execute the shell for the given job. Called from JobStart
+ *
+ * Input:
+ *	job		Job to execute
+ *
+ * Results:
+ *	None.
+ *
+ * Side Effects:
+ *	A shell is executed, outputs is altered and the Job structure added
+ *	to the job table.
+ *
+ *-----------------------------------------------------------------------
+ */
+static void
+JobExec(Job *job, char **argv)
+{
+    int	    	  cpid;	    	/* ID of new child */
+    sigset_t	  mask;
+
+    job->flags &= ~JOB_TRACED;
+
+    if (DEBUG(JOB)) {
+	int 	  i;
+
+	(void)fprintf(debug_file, "Running %s %sly\n", job->node->name, "local");
+	(void)fprintf(debug_file, "\tCommand: ");
+	for (i = 0; argv[i] != NULL; i++) {
+	    (void)fprintf(debug_file, "%s ", argv[i]);
+	}
+ 	(void)fprintf(debug_file, "\n");
+    }
+
+    /*
+     * Some jobs produce no output and it's disconcerting to have
+     * no feedback of their running (since they produce no output, the
+     * banner with their name in it never appears). This is an attempt to
+     * provide that feedback, even if nothing follows it.
+     */
+    if ((lastNode != job->node) && !(job->flags & JOB_SILENT)) {
+	MESSAGE(stdout, job->node);
+	lastNode = job->node;
+    }
+
+    /* No interruptions until this job is on the `jobs' list */
+    JobSigLock(&mask);
+
+    /* Pre-emptively mark job running, pid still zero though */
+    job->job_state = JOB_ST_RUNNING;
+
+    cpid = vFork();
+    if (cpid == -1)
+	Punt("Cannot vfork: %s", strerror(errno));
+
+    if (cpid == 0) {
+	/* Child */
+	sigset_t tmask;
+
+#ifdef USE_META
+	if (useMeta) {
+	    meta_job_child(job);
+	}
+#endif
+	/*
+	 * Reset all signal handlers; this is necessary because we also
+	 * need to unblock signals before we exec(2).
+	 */
+	JobSigReset();
+
+	/* Now unblock signals */
+	sigemptyset(&tmask);
+	JobSigUnlock(&tmask);
+
+	/*
+	 * Must duplicate the input stream down to the child's input and
+	 * reset it to the beginning (again). Since the stream was marked
+	 * close-on-exec, we must clear that bit in the new input.
+	 */
+	if (dup2(FILENO(job->cmdFILE), 0) == -1) {
+	    execError("dup2", "job->cmdFILE");
+	    _exit(1);
+	}
+	(void)fcntl(0, F_SETFD, 0);
+	(void)lseek(0, (off_t)0, SEEK_SET);
+
+	if (job->node->type & OP_MAKE) {
+		/*
+		 * Pass job token pipe to submakes.
+		 */
+		fcntl(tokenWaitJob.inPipe, F_SETFD, 0);
+		fcntl(tokenWaitJob.outPipe, F_SETFD, 0);		
+	}
+	
+	/*
+	 * Set up the child's output to be routed through the pipe
+	 * we've created for it.
+	 */
+	if (dup2(job->outPipe, 1) == -1) {
+	    execError("dup2", "job->outPipe");
+	    _exit(1);
+	}
+	/*
+	 * The output channels are marked close on exec. This bit was
+	 * duplicated by the dup2(on some systems), so we have to clear
+	 * it before routing the shell's error output to the same place as
+	 * its standard output.
+	 */
+	(void)fcntl(1, F_SETFD, 0);
+	if (dup2(1, 2) == -1) {
+	    execError("dup2", "1, 2");
+	    _exit(1);
+	}
+
+	/*
+	 * We want to switch the child into a different process family so
+	 * we can kill it and all its descendants in one fell swoop,
+	 * by killing its process family, but not commit suicide.
+	 */
+#if defined(HAVE_SETPGID)
+	(void)setpgid(0, getpid());
+#else
+#if defined(HAVE_SETSID)
+	/* XXX: dsl - I'm sure this should be setpgrp()... */
+	(void)setsid();
+#else
+	(void)setpgrp(0, getpid());
+#endif
+#endif
+
+	Var_ExportVars();
+
+	(void)execv(shellPath, argv);
+	execError("exec", shellPath);
+	_exit(1);
+    }
+
+    /* Parent, continuing after the child exec */
+    job->pid = cpid;
+
+    Trace_Log(JOBSTART, job);
+
+    /*
+     * Set the current position in the buffer to the beginning
+     * and mark another stream to watch in the outputs mask
+     */
+    job->curPos = 0;
+
+    watchfd(job);
+
+    if (job->cmdFILE != NULL && job->cmdFILE != stdout) {
+	(void)fclose(job->cmdFILE);
+	job->cmdFILE = NULL;
+    }
+
+    /*
+     * Now the job is actually running, add it to the table.
+     */
+    if (DEBUG(JOB)) {
+	fprintf(debug_file, "JobExec(%s): pid %d added to jobs table\n",
+		job->node->name, job->pid);
+	job_table_dump("job started");
+    }
+    JobSigUnlock(&mask);
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * JobMakeArgv --
+ *	Create the argv needed to execute the shell for a given job.
+ *
+ *
+ * Results:
+ *
+ * Side Effects:
+ *
+ *-----------------------------------------------------------------------
+ */
+static void
+JobMakeArgv(Job *job, char **argv)
+{
+    int	    	  argc;
+    static char args[10]; 	/* For merged arguments */
+
+    argv[0] = UNCONST(shellName);
+    argc = 1;
+
+    if ((commandShell->exit && (*commandShell->exit != '-')) ||
+	(commandShell->echo && (*commandShell->echo != '-')))
+    {
+	/*
+	 * At least one of the flags doesn't have a minus before it, so
+	 * merge them together. Have to do this because the *(&(@*#*&#$#
+	 * Bourne shell thinks its second argument is a file to source.
+	 * Grrrr. Note the ten-character limitation on the combined arguments.
+	 */
+	(void)snprintf(args, sizeof(args), "-%s%s",
+		      ((job->flags & JOB_IGNERR) ? "" :
+		       (commandShell->exit ? commandShell->exit : "")),
+		      ((job->flags & JOB_SILENT) ? "" :
+		       (commandShell->echo ? commandShell->echo : "")));
+
+	if (args[1]) {
+	    argv[argc] = args;
+	    argc++;
+	}
+    } else {
+	if (!(job->flags & JOB_IGNERR) && commandShell->exit) {
+	    argv[argc] = UNCONST(commandShell->exit);
+	    argc++;
+	}
+	if (!(job->flags & JOB_SILENT) && commandShell->echo) {
+	    argv[argc] = UNCONST(commandShell->echo);
+	    argc++;
+	}
+    }
+    argv[argc] = NULL;
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * JobStart  --
+ *	Start a target-creation process going for the target described
+ *	by the graph node gn.
+ *
+ * Input:
+ *	gn		target to create
+ *	flags		flags for the job to override normal ones.
+ *			e.g. JOB_SPECIAL or JOB_IGNDOTS
+ *	previous	The previous Job structure for this node, if any.
+ *
+ * Results:
+ *	JOB_ERROR if there was an error in the commands, JOB_FINISHED
+ *	if there isn't actually anything left to do for the job and
+ *	JOB_RUNNING if the job has been started.
+ *
+ * Side Effects:
+ *	A new Job node is created and added to the list of running
+ *	jobs. PMake is forked and a child shell created.
+ *
+ * NB: I'm fairly sure that this code is never called with JOB_SPECIAL set
+ *     JOB_IGNDOTS is never set (dsl)
+ *     Also the return value is ignored by everyone.
+ *-----------------------------------------------------------------------
+ */
+static int
+JobStart(GNode *gn, int flags)
+{
+    Job		  *job;       /* new job descriptor */
+    char	  *argv[10];  /* Argument vector to shell */
+    Boolean	  cmdsOK;     /* true if the nodes commands were all right */
+    Boolean 	  noExec;     /* Set true if we decide not to run the job */
+    int		  tfd;	      /* File descriptor to the temp file */
+
+    for (job = job_table; job < job_table_end; job++) {
+	if (job->job_state == JOB_ST_FREE)
+	    break;
+    }
+    if (job >= job_table_end)
+	Punt("JobStart no job slots vacant");
+
+    memset(job, 0, sizeof *job);
+    job->job_state = JOB_ST_SETUP;
+    if (gn->type & OP_SPECIAL)
+	flags |= JOB_SPECIAL;
+
+    job->node = gn;
+    job->tailCmds = NULL;
+
+    /*
+     * Set the initial value of the flags for this job based on the global
+     * ones and the node's attributes... Any flags supplied by the caller
+     * are also added to the field.
+     */
+    job->flags = 0;
+    if (Targ_Ignore(gn)) {
+	job->flags |= JOB_IGNERR;
+    }
+    if (Targ_Silent(gn)) {
+	job->flags |= JOB_SILENT;
+    }
+    job->flags |= flags;
+
+    /*
+     * Check the commands now so any attributes from .DEFAULT have a chance
+     * to migrate to the node
+     */
+    cmdsOK = Job_CheckCommands(gn, Error);
+
+    job->inPollfd = NULL;
+    /*
+     * If the -n flag wasn't given, we open up OUR (not the child's)
+     * temporary file to stuff commands in it. The thing is rd/wr so we don't
+     * need to reopen it to feed it to the shell. If the -n flag *was* given,
+     * we just set the file to be stdout. Cute, huh?
+     */
+    if (((gn->type & OP_MAKE) && !(noRecursiveExecute)) ||
+	    (!noExecute && !touchFlag)) {
+	/*
+	 * tfile is the name of a file into which all shell commands are
+	 * put. It is removed before the child shell is executed, unless
+	 * DEBUG(SCRIPT) is set.
+	 */
+	char *tfile;
+	sigset_t mask;
+	/*
+	 * We're serious here, but if the commands were bogus, we're
+	 * also dead...
+	 */
+	if (!cmdsOK) {
+	    PrintOnError(gn, NULL);	/* provide some clue */
+	    DieHorribly();
+	}
+
+	JobSigLock(&mask);
+	tfd = mkTempFile(TMPPAT, &tfile);
+	if (!DEBUG(SCRIPT))
+		(void)eunlink(tfile);
+	JobSigUnlock(&mask);
+
+	job->cmdFILE = fdopen(tfd, "w+");
+	if (job->cmdFILE == NULL) {
+	    Punt("Could not fdopen %s", tfile);
+	}
+	(void)fcntl(FILENO(job->cmdFILE), F_SETFD, 1);
+	/*
+	 * Send the commands to the command file, flush all its buffers then
+	 * rewind and remove the thing.
+	 */
+	noExec = FALSE;
+
+#ifdef USE_META
+	if (useMeta) {
+	    meta_job_start(job, gn);
+	    if (Targ_Silent(gn)) {	/* might have changed */
+		job->flags |= JOB_SILENT;
+	    }
+	}
+#endif
+	/*
+	 * We can do all the commands at once. hooray for sanity
+	 */
+	numCommands = 0;
+	Lst_ForEach(gn->commands, JobPrintCommand, job);
+
+	/*
+	 * If we didn't print out any commands to the shell script,
+	 * there's not much point in executing the shell, is there?
+	 */
+	if (numCommands == 0) {
+	    noExec = TRUE;
+	}
+
+	free(tfile);
+    } else if (NoExecute(gn)) {
+	/*
+	 * Not executing anything -- just print all the commands to stdout
+	 * in one fell swoop. This will still set up job->tailCmds correctly.
+	 */
+	if (lastNode != gn) {
+	    MESSAGE(stdout, gn);
+	    lastNode = gn;
+	}
+	job->cmdFILE = stdout;
+	/*
+	 * Only print the commands if they're ok, but don't die if they're
+	 * not -- just let the user know they're bad and keep going. It
+	 * doesn't do any harm in this case and may do some good.
+	 */
+	if (cmdsOK) {
+	    Lst_ForEach(gn->commands, JobPrintCommand, job);
+	}
+	/*
+	 * Don't execute the shell, thank you.
+	 */
+	noExec = TRUE;
+    } else {
+	/*
+	 * Just touch the target and note that no shell should be executed.
+	 * Set cmdFILE to stdout to make life easier. Check the commands, too,
+	 * but don't die if they're no good -- it does no harm to keep working
+	 * up the graph.
+	 */
+	job->cmdFILE = stdout;
+    	Job_Touch(gn, job->flags&JOB_SILENT);
+	noExec = TRUE;
+    }
+    /* Just in case it isn't already... */
+    (void)fflush(job->cmdFILE);
+
+    /*
+     * If we're not supposed to execute a shell, don't.
+     */
+    if (noExec) {
+	if (!(job->flags & JOB_SPECIAL))
+	    Job_TokenReturn();
+	/*
+	 * Unlink and close the command file if we opened one
+	 */
+	if (job->cmdFILE != stdout) {
+	    if (job->cmdFILE != NULL) {
+		(void)fclose(job->cmdFILE);
+		job->cmdFILE = NULL;
+	    }
+	}
+
+	/*
+	 * We only want to work our way up the graph if we aren't here because
+	 * the commands for the job were no good.
+	 */
+	if (cmdsOK && aborting == 0) {
+	    if (job->tailCmds != NULL) {
+		Lst_ForEachFrom(job->node->commands, job->tailCmds,
+				JobSaveCommand,
+			       job->node);
+	    }
+	    job->node->made = MADE;
+	    Make_Update(job->node);
+	}
+	job->job_state = JOB_ST_FREE;
+	return cmdsOK ? JOB_FINISHED : JOB_ERROR;
+    }
+
+    /*
+     * Set up the control arguments to the shell. This is based on the flags
+     * set earlier for this job.
+     */
+    JobMakeArgv(job, argv);
+
+    /* Create the pipe by which we'll get the shell's output.  */
+    JobCreatePipe(job, 3);
+
+    JobExec(job, argv);
+    return(JOB_RUNNING);
+}
+
+static char *
+JobOutput(Job *job, char *cp, char *endp, int msg)
+{
+    char *ecp;
+
+    if (commandShell->noPrint) {
+	ecp = Str_FindSubstring(cp, commandShell->noPrint);
+	while (ecp != NULL) {
+	    if (cp != ecp) {
+		*ecp = '\0';
+		if (!beSilent && msg && job->node != lastNode) {
+		    MESSAGE(stdout, job->node);
+		    lastNode = job->node;
+		}
+		/*
+		 * The only way there wouldn't be a newline after
+		 * this line is if it were the last in the buffer.
+		 * however, since the non-printable comes after it,
+		 * there must be a newline, so we don't print one.
+		 */
+		(void)fprintf(stdout, "%s", cp);
+		(void)fflush(stdout);
+	    }
+	    cp = ecp + commandShell->noPLen;
+	    if (cp != endp) {
+		/*
+		 * Still more to print, look again after skipping
+		 * the whitespace following the non-printable
+		 * command....
+		 */
+		cp++;
+		while (*cp == ' ' || *cp == '\t' || *cp == '\n') {
+		    cp++;
+		}
+		ecp = Str_FindSubstring(cp, commandShell->noPrint);
+	    } else {
+		return cp;
+	    }
+	}
+    }
+    return cp;
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * JobDoOutput  --
+ *	This function is called at different times depending on
+ *	whether the user has specified that output is to be collected
+ *	via pipes or temporary files. In the former case, we are called
+ *	whenever there is something to read on the pipe. We collect more
+ *	output from the given job and store it in the job's outBuf. If
+ *	this makes up a line, we print it tagged by the job's identifier,
+ *	as necessary.
+ *	If output has been collected in a temporary file, we open the
+ *	file and read it line by line, transfering it to our own
+ *	output channel until the file is empty. At which point we
+ *	remove the temporary file.
+ *	In both cases, however, we keep our figurative eye out for the
+ *	'noPrint' line for the shell from which the output came. If
+ *	we recognize a line, we don't print it. If the command is not
+ *	alone on the line (the character after it is not \0 or \n), we
+ *	do print whatever follows it.
+ *
+ * Input:
+ *	job		the job whose output needs printing
+ *	finish		TRUE if this is the last time we'll be called
+ *			for this job
+ *
+ * Results:
+ *	None
+ *
+ * Side Effects:
+ *	curPos may be shifted as may the contents of outBuf.
+ *-----------------------------------------------------------------------
+ */
+STATIC void
+JobDoOutput(Job *job, Boolean finish)
+{
+    Boolean       gotNL = FALSE;  /* true if got a newline */
+    Boolean       fbuf;  	  /* true if our buffer filled up */
+    int		  nr;	      	  /* number of bytes read */
+    int		  i;	      	  /* auxiliary index into outBuf */
+    int		  max;	      	  /* limit for i (end of current data) */
+    int		  nRead;      	  /* (Temporary) number of bytes read */
+
+    /*
+     * Read as many bytes as will fit in the buffer.
+     */
+end_loop:
+    gotNL = FALSE;
+    fbuf = FALSE;
+
+    nRead = read(job->inPipe, &job->outBuf[job->curPos],
+		     JOB_BUFSIZE - job->curPos);
+    if (nRead < 0) {
+	if (errno == EAGAIN)
+	    return;
+	if (DEBUG(JOB)) {
+	    perror("JobDoOutput(piperead)");
+	}
+	nr = 0;
+    } else {
+	nr = nRead;
+    }
+
+    /*
+     * If we hit the end-of-file (the job is dead), we must flush its
+     * remaining output, so pretend we read a newline if there's any
+     * output remaining in the buffer.
+     * Also clear the 'finish' flag so we stop looping.
+     */
+    if ((nr == 0) && (job->curPos != 0)) {
+	job->outBuf[job->curPos] = '\n';
+	nr = 1;
+	finish = FALSE;
+    } else if (nr == 0) {
+	finish = FALSE;
+    }
+
+    /*
+     * Look for the last newline in the bytes we just got. If there is
+     * one, break out of the loop with 'i' as its index and gotNL set
+     * TRUE.
+     */
+    max = job->curPos + nr;
+    for (i = job->curPos + nr - 1; i >= job->curPos; i--) {
+	if (job->outBuf[i] == '\n') {
+	    gotNL = TRUE;
+	    break;
+	} else if (job->outBuf[i] == '\0') {
+	    /*
+	     * Why?
+	     */
+	    job->outBuf[i] = ' ';
+	}
+    }
+
+    if (!gotNL) {
+	job->curPos += nr;
+	if (job->curPos == JOB_BUFSIZE) {
+	    /*
+	     * If we've run out of buffer space, we have no choice
+	     * but to print the stuff. sigh.
+	     */
+	    fbuf = TRUE;
+	    i = job->curPos;
+	}
+    }
+    if (gotNL || fbuf) {
+	/*
+	 * Need to send the output to the screen. Null terminate it
+	 * first, overwriting the newline character if there was one.
+	 * So long as the line isn't one we should filter (according
+	 * to the shell description), we print the line, preceded
+	 * by a target banner if this target isn't the same as the
+	 * one for which we last printed something.
+	 * The rest of the data in the buffer are then shifted down
+	 * to the start of the buffer and curPos is set accordingly.
+	 */
+	job->outBuf[i] = '\0';
+	if (i >= job->curPos) {
+	    char *cp;
+
+	    cp = JobOutput(job, job->outBuf, &job->outBuf[i], FALSE);
+
+	    /*
+	     * There's still more in that thar buffer. This time, though,
+	     * we know there's no newline at the end, so we add one of
+	     * our own free will.
+	     */
+	    if (*cp != '\0') {
+		if (!beSilent && job->node != lastNode) {
+		    MESSAGE(stdout, job->node);
+		    lastNode = job->node;
+		}
+#ifdef USE_META
+		if (useMeta) {
+		    meta_job_output(job, cp, gotNL ? "\n" : "");
+		}
+#endif
+		(void)fprintf(stdout, "%s%s", cp, gotNL ? "\n" : "");
+		(void)fflush(stdout);
+	    }
+	}
+	if (i < max - 1) {
+	    /* shift the remaining characters down */
+	    (void)memcpy(job->outBuf, &job->outBuf[i + 1], max - (i + 1));
+	    job->curPos = max - (i + 1);
+
+	} else {
+	    /*
+	     * We have written everything out, so we just start over
+	     * from the start of the buffer. No copying. No nothing.
+	     */
+	    job->curPos = 0;
+	}
+    }
+    if (finish) {
+	/*
+	 * If the finish flag is true, we must loop until we hit
+	 * end-of-file on the pipe. This is guaranteed to happen
+	 * eventually since the other end of the pipe is now closed
+	 * (we closed it explicitly and the child has exited). When
+	 * we do get an EOF, finish will be set FALSE and we'll fall
+	 * through and out.
+	 */
+	goto end_loop;
+    }
+}
+
+static void
+JobRun(GNode *targ)
+{
+#ifdef notyet
+    /*
+     * Unfortunately it is too complicated to run .BEGIN, .END,
+     * and .INTERRUPT job in the parallel job module. This has
+     * the nice side effect that it avoids a lot of other problems.
+     */
+    Lst lst = Lst_Init(FALSE);
+    Lst_AtEnd(lst, targ);
+    (void)Make_Run(lst);
+    Lst_Destroy(lst, NULL);
+    JobStart(targ, JOB_SPECIAL);
+    while (jobTokensRunning) {
+	Job_CatchOutput();
+    }
+#else
+    Compat_Make(targ, targ);
+    if (targ->made == ERROR) {
+	PrintOnError(targ, "\n\nStop.");
+	exit(1);
+    }
+#endif
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Job_CatchChildren --
+ *	Handle the exit of a child. Called from Make_Make.
+ *
+ * Input:
+ *	block		TRUE if should block on the wait
+ *
+ * Results:
+ *	none.
+ *
+ * Side Effects:
+ *	The job descriptor is removed from the list of children.
+ *
+ * Notes:
+ *	We do waits, blocking or not, according to the wisdom of our
+ *	caller, until there are no more children to report. For each
+ *	job, call JobFinish to finish things off.
+ *
+ *-----------------------------------------------------------------------
+ */
+
+void
+Job_CatchChildren(void)
+{
+    int    	  pid;	    	/* pid of dead child */
+    WAIT_T	  status;   	/* Exit/termination status */
+
+    /*
+     * Don't even bother if we know there's no one around.
+     */
+    if (jobTokensRunning == 0)
+	return;
+
+    while ((pid = waitpid((pid_t) -1, &status, WNOHANG | WUNTRACED)) > 0) {
+	if (DEBUG(JOB)) {
+	    (void)fprintf(debug_file, "Process %d exited/stopped status %x.\n", pid,
+	      WAIT_STATUS(status));
+	}
+	JobReapChild(pid, status, TRUE);
+    }
+}
+
+/*
+ * It is possible that wait[pid]() was called from elsewhere,
+ * this lets us reap jobs regardless.
+ */
+void
+JobReapChild(pid_t pid, WAIT_T status, Boolean isJobs)
+{
+    Job		  *job;	    	/* job descriptor for dead child */
+
+    /*
+     * Don't even bother if we know there's no one around.
+     */
+    if (jobTokensRunning == 0)
+	return;
+
+    job = JobFindPid(pid, JOB_ST_RUNNING, isJobs);
+    if (job == NULL) {
+	if (isJobs) {
+	    if (!lurking_children)
+		Error("Child (%d) status %x not in table?", pid, status);
+	}
+	return;				/* not ours */
+    }
+    if (WIFSTOPPED(status)) {
+	if (DEBUG(JOB)) {
+	    (void)fprintf(debug_file, "Process %d (%s) stopped.\n",
+			  job->pid, job->node->name);
+	}
+	if (!make_suspended) {
+	    switch (WSTOPSIG(status)) {
+	    case SIGTSTP:
+		(void)printf("*** [%s] Suspended\n", job->node->name);
+		break;
+	    case SIGSTOP:
+		(void)printf("*** [%s] Stopped\n", job->node->name);
+		break;
+	    default:
+		(void)printf("*** [%s] Stopped -- signal %d\n",
+			     job->node->name, WSTOPSIG(status));
+	    }
+	    job->job_suspended = 1;
+	}
+	(void)fflush(stdout);
+	return;
+    }
+
+    job->job_state = JOB_ST_FINISHED;
+    job->exit_status = WAIT_STATUS(status);
+
+    JobFinish(job, status);
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Job_CatchOutput --
+ *	Catch the output from our children, if we're using
+ *	pipes do so. Otherwise just block time until we get a
+ *	signal(most likely a SIGCHLD) since there's no point in
+ *	just spinning when there's nothing to do and the reaping
+ *	of a child can wait for a while.
+ *
+ * Results:
+ *	None
+ *
+ * Side Effects:
+ *	Output is read from pipes if we're piping.
+ * -----------------------------------------------------------------------
+ */
+void
+Job_CatchOutput(void)
+{
+    int nready;
+    Job *job;
+    int i;
+
+    (void)fflush(stdout);
+
+    /* The first fd in the list is the job token pipe */
+    do {
+	nready = poll(fds + 1 - wantToken, nfds - 1 + wantToken, POLL_MSEC);
+    } while (nready < 0 && errno == EINTR);
+
+    if (nready < 0)
+	Punt("poll: %s", strerror(errno));
+
+    if (nready > 0 && readyfd(&childExitJob)) {
+	char token = 0;
+	ssize_t count;
+	count = read(childExitJob.inPipe, &token, 1);
+	switch (count) {
+	case 0:
+	    Punt("unexpected eof on token pipe");
+	case -1:
+	    Punt("token pipe read: %s", strerror(errno));
+	case 1:
+	    if (token == DO_JOB_RESUME[0])
+		/* Complete relay requested from our SIGCONT handler */
+		JobRestartJobs();
+	    break;
+	default:
+	    abort();
+	}
+	--nready;
+    }
+
+    Job_CatchChildren();
+    if (nready == 0)
+	    return;
+
+    for (i = 2; i < nfds; i++) {
+	if (!fds[i].revents)
+	    continue;
+	job = jobfds[i];
+	if (job->job_state == JOB_ST_RUNNING)
+	    JobDoOutput(job, FALSE);
+	if (--nready == 0)
+		return;
+    }
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Job_Make --
+ *	Start the creation of a target. Basically a front-end for
+ *	JobStart used by the Make module.
+ *
+ * Results:
+ *	None.
+ *
+ * Side Effects:
+ *	Another job is started.
+ *
+ *-----------------------------------------------------------------------
+ */
+void
+Job_Make(GNode *gn)
+{
+    (void)JobStart(gn, 0);
+}
+
+void
+Shell_Init(void)
+{
+    if (shellPath == NULL) {
+	/*
+	 * We are using the default shell, which may be an absolute
+	 * path if DEFSHELL_CUSTOM is defined.
+	 */
+	shellName = commandShell->name;
+#ifdef DEFSHELL_CUSTOM
+	if (*shellName == '/') {
+	    shellPath = shellName;
+	    shellName = strrchr(shellPath, '/');
+	    shellName++;
+	} else
+#endif
+	shellPath = str_concat(_PATH_DEFSHELLDIR, shellName, STR_ADDSLASH);
+    }
+    if (commandShell->exit == NULL) {
+	commandShell->exit = "";
+    }
+    if (commandShell->echo == NULL) {
+	commandShell->echo = "";
+    }
+}
+
+/*-
+ * Returns the string literal that is used in the current command shell
+ * to produce a newline character.
+ */
+const char *
+Shell_GetNewline(void)
+{
+
+    return commandShell->newline;
+}
+
+void
+Job_SetPrefix(void)
+{
+    
+    if (targPrefix) {
+	free(targPrefix);
+    } else if (!Var_Exists(MAKE_JOB_PREFIX, VAR_GLOBAL)) {
+	Var_Set(MAKE_JOB_PREFIX, "---", VAR_GLOBAL, 0);
+    }
+
+    targPrefix = Var_Subst(NULL, "${" MAKE_JOB_PREFIX "}", VAR_GLOBAL, 0);
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Job_Init --
+ *	Initialize the process module
+ *
+ * Input:
+ *
+ * Results:
+ *	none
+ *
+ * Side Effects:
+ *	lists and counters are initialized
+ *-----------------------------------------------------------------------
+ */
+void
+Job_Init(void)
+{
+    /* Allocate space for all the job info */
+    job_table = bmake_malloc(maxJobs * sizeof *job_table);
+    memset(job_table, 0, maxJobs * sizeof *job_table);
+    job_table_end = job_table + maxJobs;
+    wantToken =	0;
+
+    aborting = 	  0;
+    errors = 	  0;
+
+    lastNode =	  NULL;
+
+    /*
+     * There is a non-zero chance that we already have children.
+     * eg after 'make -f- <<EOF'
+     * Since their termination causes a 'Child (pid) not in table' message,
+     * Collect the status of any that are already dead, and suppress the
+     * error message if there are any undead ones.
+     */
+    for (;;) {
+	int rval, status;
+	rval = waitpid((pid_t) -1, &status, WNOHANG);
+	if (rval > 0)
+	    continue;
+	if (rval == 0)
+	    lurking_children = 1;
+	break;
+    }
+
+    Shell_Init();
+
+    JobCreatePipe(&childExitJob, 3);
+
+    /* We can only need to wait for tokens, children and output from each job */
+    fds = bmake_malloc(sizeof (*fds) * (2 + maxJobs));
+    jobfds = bmake_malloc(sizeof (*jobfds) * (2 + maxJobs));
+
+    /* These are permanent entries and take slots 0 and 1 */
+    watchfd(&tokenWaitJob);
+    watchfd(&childExitJob);
+
+    sigemptyset(&caught_signals);
+    /*
+     * Install a SIGCHLD handler.
+     */
+    (void)bmake_signal(SIGCHLD, JobChildSig);
+    sigaddset(&caught_signals, SIGCHLD);
+
+#define ADDSIG(s,h)				\
+    if (bmake_signal(s, SIG_IGN) != SIG_IGN) {	\
+	sigaddset(&caught_signals, s);		\
+	(void)bmake_signal(s, h);			\
+    }
+
+    /*
+     * Catch the four signals that POSIX specifies if they aren't ignored.
+     * JobPassSig will take care of calling JobInterrupt if appropriate.
+     */
+    ADDSIG(SIGINT, JobPassSig_int)
+    ADDSIG(SIGHUP, JobPassSig_term)
+    ADDSIG(SIGTERM, JobPassSig_term)
+    ADDSIG(SIGQUIT, JobPassSig_term)
+
+    /*
+     * There are additional signals that need to be caught and passed if
+     * either the export system wants to be told directly of signals or if
+     * we're giving each job its own process group (since then it won't get
+     * signals from the terminal driver as we own the terminal)
+     */
+    ADDSIG(SIGTSTP, JobPassSig_suspend)
+    ADDSIG(SIGTTOU, JobPassSig_suspend)
+    ADDSIG(SIGTTIN, JobPassSig_suspend)
+    ADDSIG(SIGWINCH, JobCondPassSig)
+    ADDSIG(SIGCONT, JobContinueSig)
+#undef ADDSIG
+
+    (void)Job_RunTarget(".BEGIN", NULL);
+    postCommands = Targ_FindNode(".END", TARG_CREATE);
+}
+
+static void JobSigReset(void)
+{
+#define DELSIG(s)					\
+    if (sigismember(&caught_signals, s)) {		\
+	(void)bmake_signal(s, SIG_DFL);			\
+    }
+
+    DELSIG(SIGINT)
+    DELSIG(SIGHUP)
+    DELSIG(SIGQUIT)
+    DELSIG(SIGTERM)
+    DELSIG(SIGTSTP)
+    DELSIG(SIGTTOU)
+    DELSIG(SIGTTIN)
+    DELSIG(SIGWINCH)
+    DELSIG(SIGCONT)
+#undef DELSIG
+    (void)bmake_signal(SIGCHLD, SIG_DFL);
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * JobMatchShell --
+ *	Find a shell in 'shells' given its name.
+ *
+ * Results:
+ *	A pointer to the Shell structure.
+ *
+ * Side Effects:
+ *	None.
+ *
+ *-----------------------------------------------------------------------
+ */
+static Shell *
+JobMatchShell(const char *name)
+{
+    Shell	*sh;
+
+    for (sh = shells; sh->name != NULL; sh++) {
+	if (strcmp(name, sh->name) == 0)
+		return (sh);
+    }
+    return NULL;
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Job_ParseShell --
+ *	Parse a shell specification and set up commandShell, shellPath
+ *	and shellName appropriately.
+ *
+ * Input:
+ *	line		The shell spec
+ *
+ * Results:
+ *	FAILURE if the specification was incorrect.
+ *
+ * Side Effects:
+ *	commandShell points to a Shell structure (either predefined or
+ *	created from the shell spec), shellPath is the full path of the
+ *	shell described by commandShell, while shellName is just the
+ *	final component of shellPath.
+ *
+ * Notes:
+ *	A shell specification consists of a .SHELL target, with dependency
+ *	operator, followed by a series of blank-separated words. Double
+ *	quotes can be used to use blanks in words. A backslash escapes
+ *	anything (most notably a double-quote and a space) and
+ *	provides the functionality it does in C. Each word consists of
+ *	keyword and value separated by an equal sign. There should be no
+ *	unnecessary spaces in the word. The keywords are as follows:
+ *	    name  	    Name of shell.
+ *	    path  	    Location of shell.
+ *	    quiet 	    Command to turn off echoing.
+ *	    echo  	    Command to turn echoing on
+ *	    filter	    Result of turning off echoing that shouldn't be
+ *	    	  	    printed.
+ *	    echoFlag	    Flag to turn echoing on at the start
+ *	    errFlag	    Flag to turn error checking on at the start
+ *	    hasErrCtl	    True if shell has error checking control
+ *	    newline	    String literal to represent a newline char
+ *	    check 	    Command to turn on error checking if hasErrCtl
+ *	    	  	    is TRUE or template of command to echo a command
+ *	    	  	    for which error checking is off if hasErrCtl is
+ *	    	  	    FALSE.
+ *	    ignore	    Command to turn off error checking if hasErrCtl
+ *	    	  	    is TRUE or template of command to execute a
+ *	    	  	    command so as to ignore any errors it returns if
+ *	    	  	    hasErrCtl is FALSE.
+ *
+ *-----------------------------------------------------------------------
+ */
+ReturnStatus
+Job_ParseShell(char *line)
+{
+    char	**words;
+    char	**argv;
+    int		argc;
+    char	*path;
+    Shell	newShell;
+    Boolean	fullSpec = FALSE;
+    Shell	*sh;
+
+    while (isspace((unsigned char)*line)) {
+	line++;
+    }
+
+    if (shellArgv)
+	free(UNCONST(shellArgv));
+
+    memset(&newShell, 0, sizeof(newShell));
+
+    /*
+     * Parse the specification by keyword
+     */
+    words = brk_string(line, &argc, TRUE, &path);
+    if (words == NULL) {
+	Error("Unterminated quoted string [%s]", line);
+	return FAILURE;
+    }
+    shellArgv = path;
+
+    for (path = NULL, argv = words; argc != 0; argc--, argv++) {
+	    if (strncmp(*argv, "path=", 5) == 0) {
+		path = &argv[0][5];
+	    } else if (strncmp(*argv, "name=", 5) == 0) {
+		newShell.name = &argv[0][5];
+	    } else {
+		if (strncmp(*argv, "quiet=", 6) == 0) {
+		    newShell.echoOff = &argv[0][6];
+		} else if (strncmp(*argv, "echo=", 5) == 0) {
+		    newShell.echoOn = &argv[0][5];
+		} else if (strncmp(*argv, "filter=", 7) == 0) {
+		    newShell.noPrint = &argv[0][7];
+		    newShell.noPLen = strlen(newShell.noPrint);
+		} else if (strncmp(*argv, "echoFlag=", 9) == 0) {
+		    newShell.echo = &argv[0][9];
+		} else if (strncmp(*argv, "errFlag=", 8) == 0) {
+		    newShell.exit = &argv[0][8];
+		} else if (strncmp(*argv, "hasErrCtl=", 10) == 0) {
+		    char c = argv[0][10];
+		    newShell.hasErrCtl = !((c != 'Y') && (c != 'y') &&
+					   (c != 'T') && (c != 't'));
+		} else if (strncmp(*argv, "newline=", 8) == 0) {
+		    newShell.newline = &argv[0][8];
+		} else if (strncmp(*argv, "check=", 6) == 0) {
+		    newShell.errCheck = &argv[0][6];
+		} else if (strncmp(*argv, "ignore=", 7) == 0) {
+		    newShell.ignErr = &argv[0][7];
+		} else if (strncmp(*argv, "errout=", 7) == 0) {
+		    newShell.errOut = &argv[0][7];
+		} else if (strncmp(*argv, "comment=", 8) == 0) {
+		    newShell.commentChar = argv[0][8];
+		} else {
+		    Parse_Error(PARSE_FATAL, "Unknown keyword \"%s\"",
+				*argv);
+		    free(words);
+		    return(FAILURE);
+		}
+		fullSpec = TRUE;
+	    }
+    }
+
+    if (path == NULL) {
+	/*
+	 * If no path was given, the user wants one of the pre-defined shells,
+	 * yes? So we find the one s/he wants with the help of JobMatchShell
+	 * and set things up the right way. shellPath will be set up by
+	 * Shell_Init.
+	 */
+	if (newShell.name == NULL) {
+	    Parse_Error(PARSE_FATAL, "Neither path nor name specified");
+	    free(words);
+	    return(FAILURE);
+	} else {
+	    if ((sh = JobMatchShell(newShell.name)) == NULL) {
+		    Parse_Error(PARSE_WARNING, "%s: No matching shell",
+				newShell.name);
+		    free(words);
+		    return(FAILURE);
+	    }
+	    commandShell = sh;
+	    shellName = newShell.name;
+	    if (shellPath) {
+		/* Shell_Init has already been called!  Do it again. */
+		free(UNCONST(shellPath));
+		shellPath = NULL;
+		Shell_Init();
+	    }
+	}
+    } else {
+	/*
+	 * The user provided a path. If s/he gave nothing else (fullSpec is
+	 * FALSE), try and find a matching shell in the ones we know of.
+	 * Else we just take the specification at its word and copy it
+	 * to a new location. In either case, we need to record the
+	 * path the user gave for the shell.
+	 */
+	shellPath = path;
+	path = strrchr(path, '/');
+	if (path == NULL) {
+	    path = UNCONST(shellPath);
+	} else {
+	    path += 1;
+	}
+	if (newShell.name != NULL) {
+	    shellName = newShell.name;
+	} else {
+	    shellName = path;
+	}
+	if (!fullSpec) {
+	    if ((sh = JobMatchShell(shellName)) == NULL) {
+		    Parse_Error(PARSE_WARNING, "%s: No matching shell",
+				shellName);
+		    free(words);
+		    return(FAILURE);
+	    }
+	    commandShell = sh;
+	} else {
+	    commandShell = bmake_malloc(sizeof(Shell));
+	    *commandShell = newShell;
+	}
+    }
+
+    if (commandShell->echoOn && commandShell->echoOff) {
+	commandShell->hasEchoCtl = TRUE;
+    }
+
+    if (!commandShell->hasErrCtl) {
+	if (commandShell->errCheck == NULL) {
+	    commandShell->errCheck = "";
+	}
+	if (commandShell->ignErr == NULL) {
+	    commandShell->ignErr = "%s\n";
+	}
+    }
+
+    /*
+     * Do not free up the words themselves, since they might be in use by the
+     * shell specification.
+     */
+    free(words);
+    return SUCCESS;
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * JobInterrupt --
+ *	Handle the receipt of an interrupt.
+ *
+ * Input:
+ *	runINTERRUPT	Non-zero if commands for the .INTERRUPT target
+ *			should be executed
+ *	signo		signal received
+ *
+ * Results:
+ *	None
+ *
+ * Side Effects:
+ *	All children are killed. Another job will be started if the
+ *	.INTERRUPT target was given.
+ *-----------------------------------------------------------------------
+ */
+static void
+JobInterrupt(int runINTERRUPT, int signo)
+{
+    Job		*job;		/* job descriptor in that element */
+    GNode	*interrupt;	/* the node describing the .INTERRUPT target */
+    sigset_t	mask;
+    GNode	*gn;
+
+    aborting = ABORT_INTERRUPT;
+
+    JobSigLock(&mask);
+
+    for (job = job_table; job < job_table_end; job++) {
+	if (job->job_state != JOB_ST_RUNNING)
+	    continue;
+
+	gn = job->node;
+
+	if ((gn->type & (OP_JOIN|OP_PHONY)) == 0 && !Targ_Precious(gn)) {
+	    char *file = (gn->path == NULL ? gn->name : gn->path);
+	    if (!noExecute && eunlink(file) != -1) {
+		Error("*** %s removed", file);
+	    }
+	}
+	if (job->pid) {
+	    if (DEBUG(JOB)) {
+		(void)fprintf(debug_file,
+			   "JobInterrupt passing signal %d to child %d.\n",
+			   signo, job->pid);
+	    }
+	    KILLPG(job->pid, signo);
+	}
+    }
+
+    JobSigUnlock(&mask);
+
+    if (runINTERRUPT && !touchFlag) {
+	interrupt = Targ_FindNode(".INTERRUPT", TARG_NOCREATE);
+	if (interrupt != NULL) {
+	    ignoreErrors = FALSE;
+	    JobRun(interrupt);
+	}
+    }
+    Trace_Log(MAKEINTR, 0);
+    exit(signo);
+}
+
+/*
+ *-----------------------------------------------------------------------
+ * Job_Finish --
+ *	Do final processing such as the running of the commands
+ *	attached to the .END target.
+ *
+ * Results:
+ *	Number of errors reported.
+ *
+ * Side Effects:
+ *	None.
+ *-----------------------------------------------------------------------
+ */
+int
+Job_Finish(void)
+{
+    if (postCommands != NULL &&
+	(!Lst_IsEmpty(postCommands->commands) ||
+	 !Lst_IsEmpty(postCommands->children))) {
+	if (errors) {
+	    Error("Errors reported so .END ignored");
+	} else {
+	    JobRun(postCommands);
+	}
+    }
+    return(errors);
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Job_End --
+ *	Cleanup any memory used by the jobs module
+ *
+ * Results:
+ *	None.
+ *
+ * Side Effects:
+ *	Memory is freed
+ *-----------------------------------------------------------------------
+ */
+void
+Job_End(void)
+{
+#ifdef CLEANUP
+    if (shellArgv)
+	free(shellArgv);
+#endif
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Job_Wait --
+ *	Waits for all running jobs to finish and returns. Sets 'aborting'
+ *	to ABORT_WAIT to prevent other jobs from starting.
+ *
+ * Results:
+ *	None.
+ *
+ * Side Effects:
+ *	Currently running jobs finish.
+ *
+ *-----------------------------------------------------------------------
+ */
+void
+Job_Wait(void)
+{
+    aborting = ABORT_WAIT;
+    while (jobTokensRunning != 0) {
+	Job_CatchOutput();
+    }
+    aborting = 0;
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Job_AbortAll --
+ *	Abort all currently running jobs without handling output or anything.
+ *	This function is to be called only in the event of a major
+ *	error. Most definitely NOT to be called from JobInterrupt.
+ *
+ * Results:
+ *	None
+ *
+ * Side Effects:
+ *	All children are killed, not just the firstborn
+ *-----------------------------------------------------------------------
+ */
+void
+Job_AbortAll(void)
+{
+    Job		*job;	/* the job descriptor in that element */
+    WAIT_T	foo;
+
+    aborting = ABORT_ERROR;
+
+    if (jobTokensRunning) {
+	for (job = job_table; job < job_table_end; job++) {
+	    if (job->job_state != JOB_ST_RUNNING)
+		continue;
+	    /*
+	     * kill the child process with increasingly drastic signals to make
+	     * darn sure it's dead.
+	     */
+	    KILLPG(job->pid, SIGINT);
+	    KILLPG(job->pid, SIGKILL);
+	}
+    }
+
+    /*
+     * Catch as many children as want to report in at first, then give up
+     */
+    while (waitpid((pid_t) -1, &foo, WNOHANG) > 0)
+	continue;
+}
+
+
+/*-
+ *-----------------------------------------------------------------------
+ * JobRestartJobs --
+ *	Tries to restart stopped jobs if there are slots available.
+ *	Called in process context in response to a SIGCONT.
+ *
+ * Results:
+ *	None.
+ *
+ * Side Effects:
+ *	Resumes jobs.
+ *
+ *-----------------------------------------------------------------------
+ */
+static void
+JobRestartJobs(void)
+{
+    Job *job;
+
+    for (job = job_table; job < job_table_end; job++) {
+	if (job->job_state == JOB_ST_RUNNING &&
+		(make_suspended || job->job_suspended)) {
+	    if (DEBUG(JOB)) {
+		(void)fprintf(debug_file, "Restarting stopped job pid %d.\n",
+			job->pid);
+	    }
+	    if (job->job_suspended) {
+		    (void)printf("*** [%s] Continued\n", job->node->name);
+		    (void)fflush(stdout);
+	    }
+	    job->job_suspended = 0;
+	    if (KILLPG(job->pid, SIGCONT) != 0 && DEBUG(JOB)) {
+		fprintf(debug_file, "Failed to send SIGCONT to %d\n", job->pid);
+	    }
+	}
+	if (job->job_state == JOB_ST_FINISHED)
+	    /* Job exit deferred after calling waitpid() in a signal handler */
+	    JobFinish(job, job->exit_status);
+    }
+    make_suspended = 0;
+}
+
+static void
+watchfd(Job *job)
+{
+    if (job->inPollfd != NULL)
+	Punt("Watching watched job");
+
+    fds[nfds].fd = job->inPipe;
+    fds[nfds].events = POLLIN;
+    jobfds[nfds] = job;
+    job->inPollfd = &fds[nfds];
+    nfds++;
+}
+
+static void
+clearfd(Job *job)
+{
+    int i;
+    if (job->inPollfd == NULL)
+	Punt("Unwatching unwatched job");
+    i = job->inPollfd - fds;
+    nfds--;
+    /*
+     * Move last job in table into hole made by dead job.
+     */
+    if (nfds != i) {
+	fds[i] = fds[nfds];
+	jobfds[i] = jobfds[nfds];
+	jobfds[i]->inPollfd = &fds[i];
+    }
+    job->inPollfd = NULL;
+}
+
+static int
+readyfd(Job *job)
+{
+    if (job->inPollfd == NULL)
+	Punt("Polling unwatched job");
+    return (job->inPollfd->revents & POLLIN) != 0;
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * JobTokenAdd --
+ *	Put a token into the job pipe so that some make process can start
+ *	another job.
+ *
+ * Side Effects:
+ *	Allows more build jobs to be spawned somewhere.
+ *
+ *-----------------------------------------------------------------------
+ */
+
+static void
+JobTokenAdd(void)
+{
+    char tok = JOB_TOKENS[aborting], tok1;
+
+    /* If we are depositing an error token flush everything else */
+    while (tok != '+' && read(tokenWaitJob.inPipe, &tok1, 1) == 1)
+	continue;
+
+    if (DEBUG(JOB))
+	fprintf(debug_file, "(%d) aborting %d, deposit token %c\n",
+	    getpid(), aborting, JOB_TOKENS[aborting]);
+    while (write(tokenWaitJob.outPipe, &tok, 1) == -1 && errno == EAGAIN)
+	continue;
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Job_ServerStartTokenAdd --
+ *	Prep the job token pipe in the root make process.
+ *
+ *-----------------------------------------------------------------------
+ */
+
+void
+Job_ServerStart(int max_tokens, int jp_0, int jp_1)
+{
+    int i;
+    char jobarg[64];
+    
+    if (jp_0 >= 0 && jp_1 >= 0) {
+	/* Pipe passed in from parent */
+	tokenWaitJob.inPipe = jp_0;
+	tokenWaitJob.outPipe = jp_1;
+	return;
+    }
+
+    JobCreatePipe(&tokenWaitJob, 15);
+
+    snprintf(jobarg, sizeof(jobarg), "%d,%d",
+	    tokenWaitJob.inPipe, tokenWaitJob.outPipe);
+
+    Var_Append(MAKEFLAGS, "-J", VAR_GLOBAL);
+    Var_Append(MAKEFLAGS, jobarg, VAR_GLOBAL);			
+
+    /*
+     * Preload the job pipe with one token per job, save the one
+     * "extra" token for the primary job.
+     * 
+     * XXX should clip maxJobs against PIPE_BUF -- if max_tokens is
+     * larger than the write buffer size of the pipe, we will
+     * deadlock here.
+     */
+    for (i = 1; i < max_tokens; i++)
+	JobTokenAdd();
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Job_TokenReturn --
+ *	Return a withdrawn token to the pool.
+ *
+ *-----------------------------------------------------------------------
+ */
+
+void
+Job_TokenReturn(void)
+{
+    jobTokensRunning--;
+    if (jobTokensRunning < 0)
+	Punt("token botch");
+    if (jobTokensRunning || JOB_TOKENS[aborting] != '+')
+	JobTokenAdd();
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Job_TokenWithdraw --
+ *	Attempt to withdraw a token from the pool.
+ *
+ * Results:
+ *	Returns TRUE if a token was withdrawn, and FALSE if the pool
+ *	is currently empty.
+ *
+ * Side Effects:
+ * 	If pool is empty, set wantToken so that we wake up
+ *	when a token is released.
+ *
+ *-----------------------------------------------------------------------
+ */
+
+
+Boolean
+Job_TokenWithdraw(void)
+{
+    char tok, tok1;
+    int count;
+
+    wantToken = 0;
+    if (DEBUG(JOB))
+	fprintf(debug_file, "Job_TokenWithdraw(%d): aborting %d, running %d\n",
+		getpid(), aborting, jobTokensRunning);
+
+    if (aborting || (jobTokensRunning >= maxJobs))
+	return FALSE;
+
+    count = read(tokenWaitJob.inPipe, &tok, 1);
+    if (count == 0)
+	Fatal("eof on job pipe!");
+    if (count < 0 && jobTokensRunning != 0) {
+	if (errno != EAGAIN) {
+	    Fatal("job pipe read: %s", strerror(errno));
+	}
+	if (DEBUG(JOB))
+	    fprintf(debug_file, "(%d) blocked for token\n", getpid());
+	wantToken = 1;
+	return FALSE;
+    }
+
+    if (count == 1 && tok != '+') {
+	/* make being abvorted - remove any other job tokens */
+	if (DEBUG(JOB))
+	    fprintf(debug_file, "(%d) aborted by token %c\n", getpid(), tok);
+	while (read(tokenWaitJob.inPipe, &tok1, 1) == 1)
+	    continue;
+	/* And put the stopper back */
+	while (write(tokenWaitJob.outPipe, &tok, 1) == -1 && errno == EAGAIN)
+	    continue;
+	Fatal("A failure has been detected in another branch of the parallel make");
+    }
+
+    if (count == 1 && jobTokensRunning == 0)
+	/* We didn't want the token really */
+	while (write(tokenWaitJob.outPipe, &tok, 1) == -1 && errno == EAGAIN)
+	    continue;
+
+    jobTokensRunning++;
+    if (DEBUG(JOB))
+	fprintf(debug_file, "(%d) withdrew token\n", getpid());
+    return TRUE;
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Job_RunTarget --
+ *	Run the named target if found. If a filename is specified, then
+ *	set that to the sources.
+ *
+ * Results:
+ *	None
+ *
+ * Side Effects:
+ * 	exits if the target fails.
+ *
+ *-----------------------------------------------------------------------
+ */
+Boolean
+Job_RunTarget(const char *target, const char *fname) {
+    GNode *gn = Targ_FindNode(target, TARG_NOCREATE);
+
+    if (gn == NULL)
+	return FALSE;
+
+    if (fname)
+	Var_Set(ALLSRC, fname, gn, 0);
+
+    JobRun(gn);
+    if (gn->made == ERROR) {
+	PrintOnError(gn, "\n\nStop.");
+	exit(1);
+    }
+    return TRUE;
+}
+
+#ifdef USE_SELECT
+int
+emul_poll(struct pollfd *fd, int nfd, int timeout)
+{
+    fd_set rfds, wfds;
+    int i, maxfd, nselect, npoll;
+    struct timeval tv, *tvp;
+    long usecs;
+
+    FD_ZERO(&rfds);
+    FD_ZERO(&wfds);
+
+    maxfd = -1;
+    for (i = 0; i < nfd; i++) {
+	fd[i].revents = 0;
+
+	if (fd[i].events & POLLIN)
+	    FD_SET(fd[i].fd, &rfds);
+
+	if (fd[i].events & POLLOUT)
+	    FD_SET(fd[i].fd, &wfds);
+
+	if (fd[i].fd > maxfd)
+	    maxfd = fd[i].fd;
+    }
+    
+    if (maxfd >= FD_SETSIZE) {
+	Punt("Ran out of fd_set slots; " 
+	     "recompile with a larger FD_SETSIZE.");
+    }
+
+    if (timeout < 0) {
+	tvp = NULL;
+    } else {
+	usecs = timeout * 1000;
+	tv.tv_sec = usecs / 1000000;
+	tv.tv_usec = usecs % 1000000;
+        tvp = &tv;
+    }
+
+    nselect = select(maxfd + 1, &rfds, &wfds, 0, tvp);
+
+    if (nselect <= 0)
+	return nselect;
+
+    npoll = 0;
+    for (i = 0; i < nfd; i++) {
+	if (FD_ISSET(fd[i].fd, &rfds))
+	    fd[i].revents |= POLLIN;
+
+	if (FD_ISSET(fd[i].fd, &wfds))
+	    fd[i].revents |= POLLOUT;
+
+	if (fd[i].revents)
+	    npoll++;
+    }
+
+    return npoll;
+}
+#endif /* USE_SELECT */