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git/run-command.c
Shawn O. Pearce e4507ae84e Teach run-command to redirect stdout to /dev/null
Some run-command callers may wish to just discard any data that
is sent to stdout from the child.  This is a lot like our existing
no_stdin support, we just open /dev/null and duplicate the descriptor
into position.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-12 23:40:17 -07:00

145 lines
2.7 KiB
C

#include "cache.h"
#include "run-command.h"
#include "exec_cmd.h"
static inline void close_pair(int fd[2])
{
close(fd[0]);
close(fd[1]);
}
static inline void dup_devnull(int to)
{
int fd = open("/dev/null", O_RDWR);
dup2(fd, to);
close(fd);
}
int start_command(struct child_process *cmd)
{
int need_in, need_out;
int fdin[2], fdout[2];
need_in = !cmd->no_stdin && cmd->in < 0;
if (need_in) {
if (pipe(fdin) < 0)
return -ERR_RUN_COMMAND_PIPE;
cmd->in = fdin[1];
cmd->close_in = 1;
}
need_out = !cmd->no_stdout
&& !cmd->stdout_to_stderr
&& cmd->out < 0;
if (need_out) {
if (pipe(fdout) < 0) {
if (need_in)
close_pair(fdin);
return -ERR_RUN_COMMAND_PIPE;
}
cmd->out = fdout[0];
cmd->close_out = 1;
}
cmd->pid = fork();
if (cmd->pid < 0) {
if (need_in)
close_pair(fdin);
if (need_out)
close_pair(fdout);
return -ERR_RUN_COMMAND_FORK;
}
if (!cmd->pid) {
if (cmd->no_stdin)
dup_devnull(0);
else if (need_in) {
dup2(fdin[0], 0);
close_pair(fdin);
} else if (cmd->in) {
dup2(cmd->in, 0);
close(cmd->in);
}
if (cmd->no_stdout)
dup_devnull(1);
else if (cmd->stdout_to_stderr)
dup2(2, 1);
else if (need_out) {
dup2(fdout[1], 1);
close_pair(fdout);
} else if (cmd->out > 1) {
dup2(cmd->out, 1);
close(cmd->out);
}
if (cmd->git_cmd) {
execv_git_cmd(cmd->argv);
} else {
execvp(cmd->argv[0], (char *const*) cmd->argv);
}
die("exec %s failed.", cmd->argv[0]);
}
if (need_in)
close(fdin[0]);
else if (cmd->in)
close(cmd->in);
if (need_out)
close(fdout[1]);
else if (cmd->out > 1)
close(cmd->out);
return 0;
}
int finish_command(struct child_process *cmd)
{
if (cmd->close_in)
close(cmd->in);
if (cmd->close_out)
close(cmd->out);
for (;;) {
int status, code;
pid_t waiting = waitpid(cmd->pid, &status, 0);
if (waiting < 0) {
if (errno == EINTR)
continue;
error("waitpid failed (%s)", strerror(errno));
return -ERR_RUN_COMMAND_WAITPID;
}
if (waiting != cmd->pid)
return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
if (WIFSIGNALED(status))
return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
if (!WIFEXITED(status))
return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
code = WEXITSTATUS(status);
if (code)
return -code;
return 0;
}
}
int run_command(struct child_process *cmd)
{
int code = start_command(cmd);
if (code)
return code;
return finish_command(cmd);
}
int run_command_v_opt(const char **argv, int opt)
{
struct child_process cmd;
memset(&cmd, 0, sizeof(cmd));
cmd.argv = argv;
cmd.no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
cmd.git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
cmd.stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
return run_command(&cmd);
}