Avoid unnecessary strlen() calls
[git] / run-command.c
1 #include "cache.h"
2 #include "run-command.h"
3 #include "exec_cmd.h"
4
5 static inline void close_pair(int fd[2])
6 {
7         close(fd[0]);
8         close(fd[1]);
9 }
10
11 int start_command(struct child_process *cmd)
12 {
13         int need_in = !cmd->no_stdin && cmd->in < 0;
14         int fdin[2];
15
16         if (need_in) {
17                 if (pipe(fdin) < 0)
18                         return -ERR_RUN_COMMAND_PIPE;
19                 cmd->in = fdin[1];
20                 cmd->close_in = 1;
21         }
22
23         cmd->pid = fork();
24         if (cmd->pid < 0) {
25                 if (need_in)
26                         close_pair(fdin);
27                 return -ERR_RUN_COMMAND_FORK;
28         }
29
30         if (!cmd->pid) {
31                 if (cmd->no_stdin) {
32                         int fd = open("/dev/null", O_RDWR);
33                         dup2(fd, 0);
34                         close(fd);
35                 } else if (need_in) {
36                         dup2(fdin[0], 0);
37                         close_pair(fdin);
38                 } else if (cmd->in) {
39                         dup2(cmd->in, 0);
40                         close(cmd->in);
41                 }
42
43                 if (cmd->stdout_to_stderr)
44                         dup2(2, 1);
45                 if (cmd->git_cmd) {
46                         execv_git_cmd(cmd->argv);
47                 } else {
48                         execvp(cmd->argv[0], (char *const*) cmd->argv);
49                 }
50                 die("exec %s failed.", cmd->argv[0]);
51         }
52
53         if (need_in)
54                 close(fdin[0]);
55         else if (cmd->in)
56                 close(cmd->in);
57
58         return 0;
59 }
60
61 int finish_command(struct child_process *cmd)
62 {
63         if (cmd->close_in)
64                 close(cmd->in);
65
66         for (;;) {
67                 int status, code;
68                 pid_t waiting = waitpid(cmd->pid, &status, 0);
69
70                 if (waiting < 0) {
71                         if (errno == EINTR)
72                                 continue;
73                         error("waitpid failed (%s)", strerror(errno));
74                         return -ERR_RUN_COMMAND_WAITPID;
75                 }
76                 if (waiting != cmd->pid)
77                         return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
78                 if (WIFSIGNALED(status))
79                         return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
80
81                 if (!WIFEXITED(status))
82                         return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
83                 code = WEXITSTATUS(status);
84                 if (code)
85                         return -code;
86                 return 0;
87         }
88 }
89
90 int run_command(struct child_process *cmd)
91 {
92         int code = start_command(cmd);
93         if (code)
94                 return code;
95         return finish_command(cmd);
96 }
97
98 int run_command_v_opt(const char **argv, int opt)
99 {
100         struct child_process cmd;
101         memset(&cmd, 0, sizeof(cmd));
102         cmd.argv = argv;
103         cmd.no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
104         cmd.git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
105         cmd.stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
106         return run_command(&cmd);
107 }