src/common/unix_process.c

#ifndef lint
static const char       RCSid[] = "$Id$";
#endif
/*
 * Routines to communicate with separate process via dual pipes
 * Unix version
 *
 * External symbols declared in standard.h
 */

#include "copyright.h"

#include "rtprocess.h"
#include  "vfork.h"


int
open_process(           /* open communication to separate process */
SUBPROC *pd,
char    *av[]
)
{
        extern char     *getpath(), *getenv();
        char    *compath;
        int     p0[2], p1[2];

        pd->running = 0; /* not yet */
                                        /* find executable */
        compath = getpath(av[0], getenv("PATH"), 1);
        if (compath == 0)
                return(0);
        if (pipe(p0) < 0 || pipe(p1) < 0)
                return(-1);
        if ((pd->pid = vfork()) == 0) {         /* if child */
                close(p0[1]);
                close(p1[0]);
                if (p0[0] != 0) {       /* connect p0 to stdin */
                        dup2(p0[0], 0);
                        close(p0[0]);
                }
                if (p1[1] != 1) {       /* connect p1 to stdout */
                        dup2(p1[1], 1);
                        close(p1[1]);
                }
                execv(compath, av);     /* exec command */
                perror(compath);
                _exit(127);
        }
        if (pd->pid == -1)
                return(-1);
        close(p0[0]);
        close(p1[1]);
        pd->r = p1[0];
        pd->w = p0[1];
        pd->running = 1;
        return(PIPE_BUF);
}


int
close_process(          /* close pipes and wait for process */
SUBPROC *pd
)
{
        int     pid, status;

        close(pd->r);
        close(pd->w);
        pd->running = 0;
        while ((pid = wait(&status)) != -1)
                if (pid == pd->pid)
                        return(status>>8 & 0xff);
        return(-1);             /* ? unknown status */
}


Revision:	3.1
Committed:	Thu Jun 26 00:58:09 2003 UTC (20 years, 10 months ago) by schorsch
Content type:	text/plain
Branch:	MAIN
Log Message:	Abstracted process and path handling for Windows. Renamed FLOAT to RREAL because of conflict on Windows. Added conditional compiles for some signal handlers.
#	Content
1	#ifndef lint
2	static const char RCSid[] = "$Id$";
3	#endif
4	/*
5	* Routines to communicate with separate process via dual pipes
6	* Unix version
7	*
8	* External symbols declared in standard.h
9	*/
10
11	#include "copyright.h"
12
13	#include "rtprocess.h"
14	#include "vfork.h"
15
16
17	int
18	open_process( /* open communication to separate process */
19	SUBPROC *pd,
20	char *av[]
21	)
22	{
23	extern char getpath(), getenv();
24	char *compath;
25	int p0[2], p1[2];
26
27	pd->running = 0; /* not yet */
28	/* find executable */
29	compath = getpath(av[0], getenv("PATH"), 1);
30	if (compath == 0)
31	return(0);
32	if (pipe(p0) < 0 \|\| pipe(p1) < 0)
33	return(-1);
34	if ((pd->pid = vfork()) == 0) { /* if child */
35	close(p0[1]);
36	close(p1[0]);
37	if (p0[0] != 0) { /* connect p0 to stdin */
38	dup2(p0[0], 0);
39	close(p0[0]);
40	}
41	if (p1[1] != 1) { /* connect p1 to stdout */
42	dup2(p1[1], 1);
43	close(p1[1]);
44	}
45	execv(compath, av); /* exec command */
46	perror(compath);
47	_exit(127);
48	}
49	if (pd->pid == -1)
50	return(-1);
51	close(p0[0]);
52	close(p1[1]);
53	pd->r = p1[0];
54	pd->w = p0[1];
55	pd->running = 1;
56	return(PIPE_BUF);
57	}
58
59
60
61	int
62	close_process( /* close pipes and wait for process */
63	SUBPROC *pd
64	)
65	{
66	int pid, status;
67
68	close(pd->r);
69	close(pd->w);
70	pd->running = 0;
71	while ((pid = wait(&status)) != -1)
72	if (pid == pd->pid)
73	return(status>>8 & 0xff);
74	return(-1); /* ? unknown status */
75	}
76
77