1 /* CC0 license (public domain) - see LICENSE file for details */
2 #include <ccan/pipecmd/pipecmd.h>
3 #include <ccan/noerr/noerr.h>
9 static char **gather_args(const char *arg0, va_list ap)
12 char **arr = calloc(sizeof(char *), n + 1);
16 arr[0] = (char *)arg0;
18 while ((arr[n++] = va_arg(ap, char *)) != NULL) {
19 arr = realloc(arr, sizeof(char *) * (n + 1));
26 pid_t pipecmdv(int *fd_fromchild, int *fd_tochild, int *fd_errfromchild,
27 const char *cmd, va_list ap)
29 char **arr = gather_args(cmd, ap);
36 ret = pipecmdarr(fd_fromchild, fd_tochild, fd_errfromchild, arr);
41 pid_t pipecmdarr(int *fd_fromchild, int *fd_tochild, int *fd_errfromchild,
44 int tochild[2], fromchild[2], errfromchild[2], execfail[2];
49 if (pipe(tochild) != 0)
52 tochild[0] = open("/dev/null", O_RDONLY);
57 if (pipe(fromchild) != 0)
58 goto close_tochild_fail;
60 fromchild[1] = open("/dev/null", O_WRONLY);
62 goto close_tochild_fail;
64 if (fd_errfromchild) {
65 if (fd_errfromchild == fd_fromchild) {
66 errfromchild[0] = fromchild[0];
67 errfromchild[1] = fromchild[1];
69 if (pipe(errfromchild) != 0)
70 goto close_fromchild_fail;
73 errfromchild[1] = open("/dev/null", O_WRONLY);
74 if (errfromchild[1] < 0)
75 goto close_fromchild_fail;
78 if (pipe(execfail) != 0)
79 goto close_errfromchild_fail;
81 if (fcntl(execfail[1], F_SETFD, fcntl(execfail[1], F_GETFD)
83 goto close_execfail_fail;
87 goto close_execfail_fail;
94 if (fd_errfromchild && fd_errfromchild != fd_fromchild)
95 close(errfromchild[0]);
99 // Child runs command.
100 if (tochild[0] != STDIN_FILENO) {
101 if (dup2(tochild[0], STDIN_FILENO) == -1)
102 goto child_errno_fail;
105 if (fromchild[1] != STDOUT_FILENO) {
106 if (dup2(fromchild[1], STDOUT_FILENO) == -1)
107 goto child_errno_fail;
110 if (fd_errfromchild && fd_errfromchild == fd_fromchild) {
111 if (dup2(STDOUT_FILENO, STDERR_FILENO) == -1)
112 goto child_errno_fail;
113 } else if (errfromchild[1] != STDERR_FILENO) {
114 if (dup2(errfromchild[1], STDERR_FILENO) == -1)
115 goto child_errno_fail;
116 close(errfromchild[1]);
122 write(execfail[1], &err, sizeof(err));
128 close(errfromchild[1]);
130 /* Child will close this without writing on successful exec. */
131 if (read(execfail[0], &err, sizeof(err)) == sizeof(err)) {
133 waitpid(childpid, NULL, 0);
139 *fd_tochild = tochild[1];
141 *fd_fromchild = fromchild[0];
143 *fd_errfromchild = errfromchild[0];
147 close_noerr(execfail[0]);
148 close_noerr(execfail[1]);
149 close_errfromchild_fail:
151 close_noerr(errfromchild[0]);
152 close_noerr(errfromchild[1]);
153 close_fromchild_fail:
155 close_noerr(fromchild[0]);
156 close_noerr(fromchild[1]);
158 close_noerr(tochild[0]);
160 close_noerr(tochild[1]);
165 pid_t pipecmd(int *fd_fromchild, int *fd_tochild, int *fd_errfromchild,
166 const char *cmd, ...)
172 childpid = pipecmdv(fd_fromchild, fd_tochild, fd_errfromchild, cmd, ap);