1 /* CC0 license (public domain) - see LICENSE file for details */
2 #include <ccan/pipecmd/pipecmd.h>
3 #include <ccan/noerr/noerr.h>
11 static char **gather_args(const char *arg0, va_list ap)
14 char **arr = calloc(sizeof(char *), n + 1);
18 arr[0] = (char *)arg0;
20 while ((arr[n++] = va_arg(ap, char *)) != NULL) {
21 char **narr = realloc(arr, sizeof(char *) * (n + 1));
31 pid_t pipecmdv(int *fd_tochild, int *fd_fromchild, int *fd_errfromchild,
32 const char *cmd, va_list ap)
34 char **arr = gather_args(cmd, ap);
41 ret = pipecmdarr(fd_tochild, fd_fromchild, fd_errfromchild, arr);
46 pid_t pipecmdarr(int *fd_tochild, int *fd_fromchild, int *fd_errfromchild,
49 int tochild[2], fromchild[2], errfromchild[2], execfail[2];
50 /* fds for parent to close */
51 int par_close[4], num_par_close = 0;
52 /* fds for child to close */
53 int child_close[4], num_child_close = 0;
58 if (fd_tochild == &pipecmd_preserve) {
59 tochild[0] = STDIN_FILENO;
60 } else if (pipe(tochild) == 0) {
61 par_close[num_par_close++] = tochild[0];
62 child_close[num_child_close++] = tochild[1];
66 tochild[0] = open("/dev/null", O_RDONLY);
69 par_close[num_par_close++] = tochild[0];
72 if (fd_fromchild == &pipecmd_preserve) {
73 fromchild[1] = STDOUT_FILENO;
74 } else if (pipe(fromchild) == 0) {
75 par_close[num_par_close++] = fromchild[1];
76 child_close[num_child_close++] = fromchild[0];
80 fromchild[1] = open("/dev/null", O_WRONLY);
83 par_close[num_par_close++] = fromchild[1];
85 if (fd_errfromchild) {
86 if (fd_errfromchild == &pipecmd_preserve) {
87 errfromchild[1] = STDERR_FILENO;
88 } else if (fd_errfromchild == fd_fromchild) {
89 errfromchild[0] = fromchild[0];
90 errfromchild[1] = fromchild[1];
91 } else if (pipe(errfromchild) == 0) {
92 par_close[num_par_close++] = errfromchild[1];
93 child_close[num_child_close++] = errfromchild[0];
97 errfromchild[1] = open("/dev/null", O_WRONLY);
98 if (errfromchild[1] < 0)
100 par_close[num_par_close++] = errfromchild[1];
103 if (pipe(execfail) != 0)
106 par_close[num_par_close++] = execfail[1];
107 child_close[num_child_close++] = execfail[0];
109 if (fcntl(execfail[1], F_SETFD, fcntl(execfail[1], F_GETFD)
119 for (i = 0; i < num_child_close; i++)
120 close(child_close[i]);
122 // Child runs command.
123 if (tochild[0] != STDIN_FILENO) {
124 if (dup2(tochild[0], STDIN_FILENO) == -1)
125 goto child_errno_fail;
128 if (fromchild[1] != STDOUT_FILENO) {
129 if (dup2(fromchild[1], STDOUT_FILENO) == -1)
130 goto child_errno_fail;
133 if (fd_errfromchild && fd_errfromchild == fd_fromchild) {
134 if (dup2(STDOUT_FILENO, STDERR_FILENO) == -1)
135 goto child_errno_fail;
136 } else if (errfromchild[1] != STDERR_FILENO) {
137 if (dup2(errfromchild[1], STDERR_FILENO) == -1)
138 goto child_errno_fail;
139 close(errfromchild[1]);
142 /* Make (fairly!) sure all other fds are closed. */
143 int max = sysconf(_SC_OPEN_MAX);
144 for (i = 3; i < max; i++)
145 if (i != execfail[1])
152 /* Gcc's warn-unused-result fail. */
153 if (write(execfail[1], &err, sizeof(err))) {
160 for (i = 0; i < num_par_close; i++)
163 /* Child will close this without writing on successful exec. */
164 if (read(execfail[0], &err, sizeof(err)) == sizeof(err)) {
166 waitpid(childpid, NULL, 0);
171 if (fd_tochild && fd_tochild != &pipecmd_preserve)
172 *fd_tochild = tochild[1];
173 if (fd_fromchild && fd_fromchild != &pipecmd_preserve)
174 *fd_fromchild = fromchild[0];
175 if (fd_errfromchild && fd_errfromchild != &pipecmd_preserve)
176 *fd_errfromchild = errfromchild[0];
180 for (i = 0; i < num_par_close; i++)
181 close_noerr(par_close[i]);
185 pid_t pipecmd(int *fd_tochild, int *fd_fromchild, int *fd_errfromchild,
186 const char *cmd, ...)
192 childpid = pipecmdv(fd_tochild, fd_fromchild, fd_errfromchild, cmd, ap);