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/* added real/protect mode branch at runtime and real mode version
* names changed for perl
* Kai Uwe Rommel
*/
/*
Several people in the past have asked about having Unix-like pipe
calls in OS/2. The following source file, adapted from 4.3 BSD Unix,
uses a #define to give you a pipe(2) call, and contains function
definitions for popen(3) and pclose(3). Anyone with problems should
send mail to me; they seem to work fine.
Mark Towfigh
Racal Interlan, Inc.
----------------------------------cut-here------------------------------------
*/
/*
* The following code segment is derived from BSD 4.3 Unix. See
* copyright below. Any bugs, questions, improvements, or problems
* should be sent to Mark Towfigh (towfiq@interlan.interlan.com).
*
* Racal InterLan Inc.
*/
/*
* Copyright (c) 1980 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/
#include <stdio.h>
#include <stdlib.h>
#include <io.h>
#include <string.h>
#include <process.h>
#include <errno.h>
#define INCL_NOPM
#define INCL_DOS
#include <os2.h>
static FILE *dos_popen(const char *cmd, const char *flags);
static int dos_pclose(FILE *pipe);
/*
* emulate Unix pipe(2) call
*/
#define tst(a,b) (*mode == 'r'? (b) : (a))
#define READH 0
#define WRITEH 1
static int popen_pid[20];
FILE *mypopen(char *cmd, char *mode)
{
int p[2];
register myside, hisside, save_stream;
char *shell = getenv("COMPSPEC");
if ( shell == NULL )
shell = "C:\\OS2\\CMD.EXE";
if ( _osmode == DOS_MODE )
return dos_popen(cmd, mode);
if ( _pipe(p, 4096, 0) )
return NULL;
myside = tst(p[WRITEH], p[READH]);
hisside = tst(p[READH], p[WRITEH]);
/* set up file descriptors for remote function */
save_stream = dup(tst(0, 1)); /* don't lose stdin/out! */
if (dup2(hisside, tst(0, 1)) < 0)
{
perror("dup2");
return NULL;
}
close(hisside);
/*
* make sure that we can close our side of the pipe, by
* preventing it from being inherited!
*/
/* set no-inheritance flag */
DosSetFHandState(myside, OPEN_FLAGS_NOINHERIT);
/* execute the command: it will inherit our other file descriptors */
popen_pid[myside] = spawnlp(P_NOWAIT, shell, shell, "/C", cmd, NULL);
/* now restore our previous file descriptors */
if (dup2(save_stream, tst(0, 1)) < 0) /* retrieve stdin/out */
{
perror("dup2");
return NULL;
}
close(save_stream);
return fdopen(myside, mode); /* return a FILE pointer */
}
int mypclose(FILE *ptr)
{
register f;
int status;
if ( _osmode == DOS_MODE )
return dos_pclose(ptr);
f = fileno(ptr);
fclose(ptr);
/* wait for process to terminate */
cwait(&status, popen_pid[f], WAIT_GRANDCHILD);
return status;
}
int pipe(int *filedes)
{
int res;
if ( res = _pipe(filedes, 4096, 0) )
return res;
DosSetFHandState(filedes[0], OPEN_FLAGS_NOINHERIT);
DosSetFHandState(filedes[1], OPEN_FLAGS_NOINHERIT);
return 0;
}
/* this is the MS-DOS version */
typedef enum { unopened = 0, reading, writing } pipemode;
static struct
{
char *name;
char *command;
pipemode pmode;
}
pipes[_NFILE];
static FILE *dos_popen(const char *command, const char *mode)
{
FILE *current;
char name[128];
char *tmp = getenv("TMP");
int cur;
pipemode curmode;
/*
** decide on mode.
*/
if(strchr(mode, 'r') != NULL)
curmode = reading;
else if(strchr(mode, 'w') != NULL)
curmode = writing;
else
return NULL;
/*
** get a name to use.
*/
strcpy(name, tmp ? tmp : "\\");
if ( name[strlen(name) - 1] != '\\' )
strcat(name, "\\");
strcat(name, "piXXXXXX");
mktemp(name);
/*
** If we're reading, just call system to get a file filled with
** output.
*/
if(curmode == reading)
{
char cmd[256];
sprintf(cmd,"%s > %s", command, name);
system(cmd);
if((current = fopen(name, mode)) == NULL)
return NULL;
}
else
{
if((current = fopen(name, mode)) == NULL)
return NULL;
}
cur = fileno(current);
pipes[cur].name = strdup(name);
pipes[cur].command = strdup(command);
pipes[cur].pmode = curmode;
return current;
}
static int dos_pclose(FILE * current)
{
int cur = fileno(current), rval;
char command[256];
/*
** check for an open file.
*/
if(pipes[cur].pmode == unopened)
return -1;
if(pipes[cur].pmode == reading)
{
/*
** input pipes are just files we're done with.
*/
rval = fclose(current);
unlink(pipes[cur].name);
}
else
{
/*
** output pipes are temporary files we have
** to cram down the throats of programs.
*/
fclose(current);
sprintf(command,"%s < %s", pipes[cur].command, pipes[cur].name);
rval = system(command);
unlink(pipes[cur].name);
}
/*
** clean up current pipe.
*/
free(pipes[cur].name);
free(pipes[cur].command);
pipes[cur].pmode = unopened;
return rval;
}
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