run_command: report system call errors instead of returning error codes
[git/dscho.git] / run-command.h
blobac6c09c8967793586eb3830e544f535a3a01ede5
1 #ifndef RUN_COMMAND_H
2 #define RUN_COMMAND_H
4 struct child_process {
5 const char **argv;
6 pid_t pid;
7 /*
8 * Using .in, .out, .err:
9 * - Specify 0 for no redirections (child inherits stdin, stdout,
10 * stderr from parent).
11 * - Specify -1 to have a pipe allocated as follows:
12 * .in: returns the writable pipe end; parent writes to it,
13 * the readable pipe end becomes child's stdin
14 * .out, .err: returns the readable pipe end; parent reads from
15 * it, the writable pipe end becomes child's stdout/stderr
16 * The caller of start_command() must close the returned FDs
17 * after it has completed reading from/writing to it!
18 * - Specify > 0 to set a channel to a particular FD as follows:
19 * .in: a readable FD, becomes child's stdin
20 * .out: a writable FD, becomes child's stdout/stderr
21 * .err > 0 not supported
22 * The specified FD is closed by start_command(), even in case
23 * of errors!
25 int in;
26 int out;
27 int err;
28 const char *dir;
29 const char *const *env;
30 unsigned no_stdin:1;
31 unsigned no_stdout:1;
32 unsigned no_stderr:1;
33 unsigned git_cmd:1; /* if this is to be git sub-command */
34 unsigned stdout_to_stderr:1;
35 void (*preexec_cb)(void);
38 int start_command(struct child_process *);
39 int finish_command(struct child_process *);
40 int run_command(struct child_process *);
42 extern int run_hook(const char *index_file, const char *name, ...);
44 #define RUN_COMMAND_NO_STDIN 1
45 #define RUN_GIT_CMD 2 /*If this is to be git sub-command */
46 #define RUN_COMMAND_STDOUT_TO_STDERR 4
47 int run_command_v_opt(const char **argv, int opt);
50 * env (the environment) is to be formatted like environ: "VAR=VALUE".
51 * To unset an environment variable use just "VAR".
53 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env);
56 * The purpose of the following functions is to feed a pipe by running
57 * a function asynchronously and providing output that the caller reads.
59 * It is expected that no synchronization and mutual exclusion between
60 * the caller and the feed function is necessary so that the function
61 * can run in a thread without interfering with the caller.
63 struct async {
65 * proc writes to fd and closes it;
66 * returns 0 on success, non-zero on failure
68 int (*proc)(int fd, void *data);
69 void *data;
70 int out; /* caller reads from here and closes it */
71 #ifndef __MINGW32__
72 pid_t pid;
73 #else
74 HANDLE tid;
75 int fd_for_proc;
76 #endif
79 int start_async(struct async *async);
80 int finish_async(struct async *async);
82 #endif