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[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 static inline void dup_devnull(int to)
12 {
13         int fd = open("/dev/null", O_RDWR);
14         dup2(fd, to);
15         close(fd);
16 }
17
18 int start_command(struct child_process *cmd)
19 {
20         int need_in, need_out;
21         int fdin[2], fdout[2];
22
23         need_in = !cmd->no_stdin && cmd->in < 0;
24         if (need_in) {
25                 if (pipe(fdin) < 0)
26                         return -ERR_RUN_COMMAND_PIPE;
27                 cmd->in = fdin[1];
28                 cmd->close_in = 1;
29         }
30
31         need_out = !cmd->no_stdout
32                 && !cmd->stdout_to_stderr
33                 && cmd->out < 0;
34         if (need_out) {
35                 if (pipe(fdout) < 0) {
36                         if (need_in)
37                                 close_pair(fdin);
38                         return -ERR_RUN_COMMAND_PIPE;
39                 }
40                 cmd->out = fdout[0];
41                 cmd->close_out = 1;
42         }
43
44         cmd->pid = fork();
45         if (cmd->pid < 0) {
46                 if (need_in)
47                         close_pair(fdin);
48                 if (need_out)
49                         close_pair(fdout);
50                 return -ERR_RUN_COMMAND_FORK;
51         }
52
53         if (!cmd->pid) {
54                 if (cmd->no_stdin)
55                         dup_devnull(0);
56                 else if (need_in) {
57                         dup2(fdin[0], 0);
58                         close_pair(fdin);
59                 } else if (cmd->in) {
60                         dup2(cmd->in, 0);
61                         close(cmd->in);
62                 }
63
64                 if (cmd->no_stdout)
65                         dup_devnull(1);
66                 else if (cmd->stdout_to_stderr)
67                         dup2(2, 1);
68                 else if (need_out) {
69                         dup2(fdout[1], 1);
70                         close_pair(fdout);
71                 } else if (cmd->out > 1) {
72                         dup2(cmd->out, 1);
73                         close(cmd->out);
74                 }
75
76                 if (cmd->git_cmd) {
77                         execv_git_cmd(cmd->argv);
78                 } else {
79                         execvp(cmd->argv[0], (char *const*) cmd->argv);
80                 }
81                 die("exec %s failed.", cmd->argv[0]);
82         }
83
84         if (need_in)
85                 close(fdin[0]);
86         else if (cmd->in)
87                 close(cmd->in);
88
89         if (need_out)
90                 close(fdout[1]);
91         else if (cmd->out > 1)
92                 close(cmd->out);
93
94         return 0;
95 }
96
97 int finish_command(struct child_process *cmd)
98 {
99         if (cmd->close_in)
100                 close(cmd->in);
101         if (cmd->close_out)
102                 close(cmd->out);
103
104         for (;;) {
105                 int status, code;
106                 pid_t waiting = waitpid(cmd->pid, &status, 0);
107
108                 if (waiting < 0) {
109                         if (errno == EINTR)
110                                 continue;
111                         error("waitpid failed (%s)", strerror(errno));
112                         return -ERR_RUN_COMMAND_WAITPID;
113                 }
114                 if (waiting != cmd->pid)
115                         return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
116                 if (WIFSIGNALED(status))
117                         return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
118
119                 if (!WIFEXITED(status))
120                         return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
121                 code = WEXITSTATUS(status);
122                 if (code)
123                         return -code;
124                 return 0;
125         }
126 }
127
128 int run_command(struct child_process *cmd)
129 {
130         int code = start_command(cmd);
131         if (code)
132                 return code;
133         return finish_command(cmd);
134 }
135
136 int run_command_v_opt(const char **argv, int opt)
137 {
138         struct child_process cmd;
139         memset(&cmd, 0, sizeof(cmd));
140         cmd.argv = argv;
141         cmd.no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
142         cmd.git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
143         cmd.stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
144         return run_command(&cmd);
145 }