git.el: Fix typo in git-update-saved-file error handling.
[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->dir && chdir(cmd->dir))
77                         die("exec %s: cd to %s failed (%s)", cmd->argv[0],
78                             cmd->dir, strerror(errno));
79                 if (cmd->env) {
80                         for (; *cmd->env; cmd->env++) {
81                                 if (strchr(*cmd->env, '='))
82                                         putenv((char*)*cmd->env);
83                                 else
84                                         unsetenv(*cmd->env);
85                         }
86                 }
87                 if (cmd->git_cmd) {
88                         execv_git_cmd(cmd->argv);
89                 } else {
90                         execvp(cmd->argv[0], (char *const*) cmd->argv);
91                 }
92                 die("exec %s failed.", cmd->argv[0]);
93         }
94
95         if (need_in)
96                 close(fdin[0]);
97         else if (cmd->in)
98                 close(cmd->in);
99
100         if (need_out)
101                 close(fdout[1]);
102         else if (cmd->out > 1)
103                 close(cmd->out);
104
105         return 0;
106 }
107
108 int finish_command(struct child_process *cmd)
109 {
110         if (cmd->close_in)
111                 close(cmd->in);
112         if (cmd->close_out)
113                 close(cmd->out);
114
115         for (;;) {
116                 int status, code;
117                 pid_t waiting = waitpid(cmd->pid, &status, 0);
118
119                 if (waiting < 0) {
120                         if (errno == EINTR)
121                                 continue;
122                         error("waitpid failed (%s)", strerror(errno));
123                         return -ERR_RUN_COMMAND_WAITPID;
124                 }
125                 if (waiting != cmd->pid)
126                         return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
127                 if (WIFSIGNALED(status))
128                         return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
129
130                 if (!WIFEXITED(status))
131                         return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
132                 code = WEXITSTATUS(status);
133                 if (code)
134                         return -code;
135                 return 0;
136         }
137 }
138
139 int run_command(struct child_process *cmd)
140 {
141         int code = start_command(cmd);
142         if (code)
143                 return code;
144         return finish_command(cmd);
145 }
146
147 static void prepare_run_command_v_opt(struct child_process *cmd,
148                                       const char **argv,
149                                       int opt)
150 {
151         memset(cmd, 0, sizeof(*cmd));
152         cmd->argv = argv;
153         cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
154         cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
155         cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
156 }
157
158 int run_command_v_opt(const char **argv, int opt)
159 {
160         struct child_process cmd;
161         prepare_run_command_v_opt(&cmd, argv, opt);
162         return run_command(&cmd);
163 }
164
165 int run_command_v_opt_cd(const char **argv, int opt, const char *dir)
166 {
167         struct child_process cmd;
168         prepare_run_command_v_opt(&cmd, argv, opt);
169         cmd.dir = dir;
170         return run_command(&cmd);
171 }
172
173 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
174 {
175         struct child_process cmd;
176         prepare_run_command_v_opt(&cmd, argv, opt);
177         cmd.dir = dir;
178         cmd.env = env;
179         return run_command(&cmd);
180 }