1 files changed, 145 insertions, 0 deletions
diff --git a/run-command.c b/run-command.c
new file mode 100644
index 0000000..eff523e
--- /dev/null
+++ b/run-command.c
@@ -0,0 +1,145 @@
+#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);
+}