1#ifndef RUN_COMMAND_H
2#define RUN_COMMAND_H
3
4#ifndef NO_PTHREADS
5#include <pthread.h>
6#endif
7
8#include "argv-array.h"
9
10struct child_process {
11 const char **argv;
12 struct argv_array args;
13 struct argv_array env_array;
14 pid_t pid;
15 /*
16 * Using .in, .out, .err:
17 * - Specify 0 for no redirections (child inherits stdin, stdout,
18 * stderr from parent).
19 * - Specify -1 to have a pipe allocated as follows:
20 * .in: returns the writable pipe end; parent writes to it,
21 * the readable pipe end becomes child's stdin
22 * .out, .err: returns the readable pipe end; parent reads from
23 * it, the writable pipe end becomes child's stdout/stderr
24 * The caller of start_command() must close the returned FDs
25 * after it has completed reading from/writing to it!
26 * - Specify > 0 to set a channel to a particular FD as follows:
27 * .in: a readable FD, becomes child's stdin
28 * .out: a writable FD, becomes child's stdout/stderr
29 * .err: a writable FD, becomes child's stderr
30 * The specified FD is closed by start_command(), even in case
31 * of errors!
32 */
33 int in;
34 int out;
35 int err;
36 const char *dir;
37 const char *const *env;
38 unsigned no_stdin:1;
39 unsigned no_stdout:1;
40 unsigned no_stderr:1;
41 unsigned git_cmd:1; /* if this is to be git sub-command */
42 unsigned silent_exec_failure:1;
43 unsigned stdout_to_stderr:1;
44 unsigned use_shell:1;
45 unsigned clean_on_exit:1;
46 unsigned wait_after_clean:1;
47 void (*clean_on_exit_handler)(struct child_process *process);
48 void *clean_on_exit_handler_cbdata;
49};
50
51#define CHILD_PROCESS_INIT { NULL, ARGV_ARRAY_INIT, ARGV_ARRAY_INIT }
52void child_process_init(struct child_process *);
53void child_process_clear(struct child_process *);
54extern int is_executable(const char *name);
55
56int start_command(struct child_process *);
57int finish_command(struct child_process *);
58int finish_command_in_signal(struct child_process *);
59int run_command(struct child_process *);
60
61/*
62 * Returns the path to the hook file, or NULL if the hook is missing
63 * or disabled. Note that this points to static storage that will be
64 * overwritten by further calls to find_hook and run_hook_*.
65 */
66extern const char *find_hook(const char *name);
67LAST_ARG_MUST_BE_NULL
68extern int run_hook_le(const char *const *env, const char *name, ...);
69extern int run_hook_ve(const char *const *env, const char *name, va_list args);
70
71#define RUN_COMMAND_NO_STDIN 1
72#define RUN_GIT_CMD 2 /*If this is to be git sub-command */
73#define RUN_COMMAND_STDOUT_TO_STDERR 4
74#define RUN_SILENT_EXEC_FAILURE 8
75#define RUN_USING_SHELL 16
76#define RUN_CLEAN_ON_EXIT 32
77int run_command_v_opt(const char **argv, int opt);
78
79/*
80 * env (the environment) is to be formatted like environ: "VAR=VALUE".
81 * To unset an environment variable use just "VAR".
82 */
83int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env);
84
85/**
86 * Execute the given command, sending "in" to its stdin, and capturing its
87 * stdout and stderr in the "out" and "err" strbufs. Any of the three may
88 * be NULL to skip processing.
89 *
90 * Returns -1 if starting the command fails or reading fails, and otherwise
91 * returns the exit code of the command. Any output collected in the
92 * buffers is kept even if the command returns a non-zero exit. The hint fields
93 * gives starting sizes for the strbuf allocations.
94 *
95 * The fields of "cmd" should be set up as they would for a normal run_command
96 * invocation. But note that there is no need to set the in, out, or err
97 * fields; pipe_command handles that automatically.
98 */
99int pipe_command(struct child_process *cmd,
100 const char *in, size_t in_len,
101 struct strbuf *out, size_t out_hint,
102 struct strbuf *err, size_t err_hint);
103
104/**
105 * Convenience wrapper around pipe_command for the common case
106 * of capturing only stdout.
107 */
108static inline int capture_command(struct child_process *cmd,
109 struct strbuf *out,
110 size_t hint)
111{
112 return pipe_command(cmd, NULL, 0, out, hint, NULL, 0);
113}
114
115/*
116 * The purpose of the following functions is to feed a pipe by running
117 * a function asynchronously and providing output that the caller reads.
118 *
119 * It is expected that no synchronization and mutual exclusion between
120 * the caller and the feed function is necessary so that the function
121 * can run in a thread without interfering with the caller.
122 */
123struct async {
124 /*
125 * proc reads from in; closes it before return
126 * proc writes to out; closes it before return
127 * returns 0 on success, non-zero on failure
128 */
129 int (*proc)(int in, int out, void *data);
130 void *data;
131 int in; /* caller writes here and closes it */
132 int out; /* caller reads from here and closes it */
133#ifdef NO_PTHREADS
134 pid_t pid;
135#else
136 pthread_t tid;
137 int proc_in;
138 int proc_out;
139#endif
140 int isolate_sigpipe;
141};
142
143int start_async(struct async *async);
144int finish_async(struct async *async);
145int in_async(void);
146void check_pipe(int err);
147
148/**
149 * This callback should initialize the child process and preload the
150 * error channel if desired. The preloading of is useful if you want to
151 * have a message printed directly before the output of the child process.
152 * pp_cb is the callback cookie as passed to run_processes_parallel.
153 * You can store a child process specific callback cookie in pp_task_cb.
154 *
155 * Even after returning 0 to indicate that there are no more processes,
156 * this function will be called again until there are no more running
157 * child processes.
158 *
159 * Return 1 if the next child is ready to run.
160 * Return 0 if there are currently no more tasks to be processed.
161 * To send a signal to other child processes for abortion,
162 * return the negative signal number.
163 */
164typedef int (*get_next_task_fn)(struct child_process *cp,
165 struct strbuf *out,
166 void *pp_cb,
167 void **pp_task_cb);
168
169/**
170 * This callback is called whenever there are problems starting
171 * a new process.
172 *
173 * You must not write to stdout or stderr in this function. Add your
174 * message to the strbuf out instead, which will be printed without
175 * messing up the output of the other parallel processes.
176 *
177 * pp_cb is the callback cookie as passed into run_processes_parallel,
178 * pp_task_cb is the callback cookie as passed into get_next_task_fn.
179 *
180 * Return 0 to continue the parallel processing. To abort return non zero.
181 * To send a signal to other child processes for abortion, return
182 * the negative signal number.
183 */
184typedef int (*start_failure_fn)(struct strbuf *out,
185 void *pp_cb,
186 void *pp_task_cb);
187
188/**
189 * This callback is called on every child process that finished processing.
190 *
191 * You must not write to stdout or stderr in this function. Add your
192 * message to the strbuf out instead, which will be printed without
193 * messing up the output of the other parallel processes.
194 *
195 * pp_cb is the callback cookie as passed into run_processes_parallel,
196 * pp_task_cb is the callback cookie as passed into get_next_task_fn.
197 *
198 * Return 0 to continue the parallel processing. To abort return non zero.
199 * To send a signal to other child processes for abortion, return
200 * the negative signal number.
201 */
202typedef int (*task_finished_fn)(int result,
203 struct strbuf *out,
204 void *pp_cb,
205 void *pp_task_cb);
206
207/**
208 * Runs up to n processes at the same time. Whenever a process can be
209 * started, the callback get_next_task_fn is called to obtain the data
210 * required to start another child process.
211 *
212 * The children started via this function run in parallel. Their output
213 * (both stdout and stderr) is routed to stderr in a manner that output
214 * from different tasks does not interleave.
215 *
216 * start_failure_fn and task_finished_fn can be NULL to omit any
217 * special handling.
218 */
219int run_processes_parallel(int n,
220 get_next_task_fn,
221 start_failure_fn,
222 task_finished_fn,
223 void *pp_cb);
224
225#endif
226