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Diffstat (limited to 'libiberty/pex-unix.c')
| -rw-r--r-- | libiberty/pex-unix.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/libiberty/pex-unix.c b/libiberty/pex-unix.c new file mode 100644 index 00000000000..14fe71ed09c --- /dev/null +++ b/libiberty/pex-unix.c @@ -0,0 +1,166 @@ +/* Utilities to execute a program in a subprocess (possibly linked by pipes + with other subprocesses), and wait for it. Generic Unix version + (also used for UWIN and VMS). + Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2003 + Free Software Foundation, Inc. + +This file is part of the libiberty library. +Libiberty is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public +License as published by the Free Software Foundation; either +version 2 of the License, or (at your option) any later version. + +Libiberty is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with libiberty; see the file COPYING.LIB. If not, +write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, +Boston, MA 02111-1307, USA. */ + +#include "pex-common.h" + +#include <stdio.h> +#include <errno.h> +#ifdef NEED_DECLARATION_ERRNO +extern int errno; +#endif +#ifdef HAVE_STRING_H +#include <string.h> +#endif +#ifdef HAVE_UNISTD_H +#include <unistd.h> +#endif +#ifdef HAVE_STDLIB_H +#include <stdlib.h> +#endif +#ifdef HAVE_SYS_WAIT_H +#include <sys/wait.h> +#endif + +#ifndef HAVE_WAITPID +#define waitpid(pid, status, flags) wait(status) +#endif + +extern int execv (); +extern int execvp (); + +int +pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags) + const char *program; + char * const *argv; + const char *this_pname; + const char *temp_base ATTRIBUTE_UNUSED; + char **errmsg_fmt, **errmsg_arg; + int flags; +{ + int (*func)() = (flags & PEXECUTE_SEARCH ? execvp : execv); + int pid; + int pdes[2]; + int input_desc, output_desc; + int retries, sleep_interval; + /* Pipe waiting from last process, to be used as input for the next one. + Value is STDIN_FILE_NO if no pipe is waiting + (i.e. the next command is the first of a group). */ + static int last_pipe_input; + + /* If this is the first process, initialize. */ + if (flags & PEXECUTE_FIRST) + last_pipe_input = STDIN_FILE_NO; + + input_desc = last_pipe_input; + + /* If this isn't the last process, make a pipe for its output, + and record it as waiting to be the input to the next process. */ + if (! (flags & PEXECUTE_LAST)) + { + if (pipe (pdes) < 0) + { + *errmsg_fmt = "pipe"; + *errmsg_arg = NULL; + return -1; + } + output_desc = pdes[WRITE_PORT]; + last_pipe_input = pdes[READ_PORT]; + } + else + { + /* Last process. */ + output_desc = STDOUT_FILE_NO; + last_pipe_input = STDIN_FILE_NO; + } + + /* Fork a subprocess; wait and retry if it fails. */ + sleep_interval = 1; + pid = -1; + for (retries = 0; retries < 4; retries++) + { + pid = fork (); + if (pid >= 0) + break; + sleep (sleep_interval); + sleep_interval *= 2; + } + + switch (pid) + { + case -1: + *errmsg_fmt = "fork"; + *errmsg_arg = NULL; + return -1; + + case 0: /* child */ + /* Move the input and output pipes into place, if necessary. */ + if (input_desc != STDIN_FILE_NO) + { + close (STDIN_FILE_NO); + dup (input_desc); + close (input_desc); + } + if (output_desc != STDOUT_FILE_NO) + { + close (STDOUT_FILE_NO); + dup (output_desc); + close (output_desc); + } + + /* Close the parent's descs that aren't wanted here. */ + if (last_pipe_input != STDIN_FILE_NO) + close (last_pipe_input); + + /* Exec the program. */ + (*func) (program, argv); + + fprintf (stderr, "%s: ", this_pname); + fprintf (stderr, install_error_msg, program); + fprintf (stderr, ": %s\n", xstrerror (errno)); + exit (-1); + /* NOTREACHED */ + return 0; + + default: + /* In the parent, after forking. + Close the descriptors that we made for this child. */ + if (input_desc != STDIN_FILE_NO) + close (input_desc); + if (output_desc != STDOUT_FILE_NO) + close (output_desc); + + /* Return child's process number. */ + return pid; + } +} + +int +pwait (pid, status, flags) + int pid; + int *status; + int flags ATTRIBUTE_UNUSED; +{ + /* ??? Here's an opportunity to canonicalize the values in STATUS. + Needed? */ + pid = waitpid (pid, status, 0); + return pid; +} |