1 #include <fcntl.h>
2 #include <unistd.h>
3 #include <errno.h>
4 #include <string.h>
5 #include <spawn.h>
6 #include <unsupported_api.h>
7 #include "stdio_impl.h"
8 #include "syscall.h"
9
10 extern char **__environ;
11
popen(const char * cmd,const char * mode)12 FILE *popen(const char *cmd, const char *mode)
13 {
14 int p[2], op, e;
15 pid_t pid;
16 FILE *f;
17 posix_spawn_file_actions_t fa;
18
19 UNSUPPORTED_API_VOID(LITEOS_A);
20 if (*mode == 'r') {
21 op = 0;
22 } else if (*mode == 'w') {
23 op = 1;
24 } else {
25 errno = EINVAL;
26 return 0;
27 }
28
29 if (pipe2(p, O_CLOEXEC)) return NULL;
30 f = fdopen(p[op], mode);
31 if (!f) {
32 __syscall(SYS_close, p[0]);
33 __syscall(SYS_close, p[1]);
34 return NULL;
35 }
36
37 e = ENOMEM;
38 if (!posix_spawn_file_actions_init(&fa)) {
39 for (FILE *l = *__ofl_lock(); l; l=l->next)
40 if (l->pipe_pid && posix_spawn_file_actions_addclose(&fa, l->fd))
41 goto fail;
42 if (!posix_spawn_file_actions_adddup2(&fa, p[1-op], 1-op)) {
43 if (!(e = posix_spawn(&pid, "/bin/sh", &fa, 0,
44 (char *[]){ "sh", "-c", (char *)cmd, 0 }, __environ))) {
45 posix_spawn_file_actions_destroy(&fa);
46 f->pipe_pid = pid;
47 if (!strchr(mode, 'e'))
48 fcntl(p[op], F_SETFD, 0);
49 __syscall(SYS_close, p[1-op]);
50 __ofl_unlock();
51 return f;
52 }
53 }
54 fail:
55 __ofl_unlock();
56 posix_spawn_file_actions_destroy(&fa);
57 }
58 fclose(f);
59 __syscall(SYS_close, p[1-op]);
60
61 errno = e;
62 return 0;
63 }
64