summaryrefslogtreecommitdiff
path: root/src/util.c
blob: 8cf06086578f1ea80160134e6bbb44b52986f3a8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
//
// Copyright 2007 Johannes Hofmann <Johannes.Hofmann@gmx.de>
//
// This software may be used and distributed according to the terms
// of the GNU General Public License, incorporated herein by reference.

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>

#include "util.h"

FILE *
pexecvp(const char *file, char *const argv[], pid_t *pid, char *type) {
	FILE *iop;
	int   pdes[2];

	if (pipe(pdes) < 0) {
		return NULL;
	}

	*pid = vfork();

	if (*pid == -1) {
		perror("vfork");
		close(pdes[0]);
		close(pdes[1]);
		return NULL;
	} else if (*pid == 0) {
		/* child */

		if (*type == 'r') {
			close(pdes[0]);
			if (pdes[1] != STDOUT_FILENO) {
				dup2(pdes[1], STDOUT_FILENO);
				close(pdes[1]);
			}
		} else {
			close(pdes[1]);
			if (pdes[0] != STDIN_FILENO) {
				dup2(pdes[0], STDIN_FILENO);
				close(pdes[0]);
			}
		}

		execvp(file, argv);
		exit(127);
	} else {
		/* parent */ 
		if (*type == 'r') {
			iop = fdopen(pdes[0], "r");
			close(pdes[1]);
		} else {
			iop = fdopen(pdes[1], "w");
			close(pdes[0]);
		}
		return iop;
	}
}