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b1bf95bb JW |
1 | #ifndef RUN_COMMAND_H |
2 | #define RUN_COMMAND_H | |
3 | ||
10bc232d | 4 | #include "thread-utils.h" |
200a76b7 | 5 | |
dbbcd44f | 6 | #include "strvec.h" |
c460c0ec | 7 | |
4c4066d9 HW |
8 | /** |
9 | * The run-command API offers a versatile tool to run sub-processes with | |
10 | * redirected input and output as well as with a modified environment | |
11 | * and an alternate current directory. | |
12 | * | |
13 | * A similar API offers the capability to run a function asynchronously, | |
14 | * which is primarily used to capture the output that the function | |
15 | * produces in the caller in order to process it. | |
16 | */ | |
17 | ||
18 | ||
19 | /** | |
20 | * This describes the arguments, redirections, and environment of a | |
21 | * command to run in a sub-process. | |
22 | * | |
23 | * The caller: | |
24 | * | |
25 | * 1. allocates and clears (using child_process_init() or | |
26 | * CHILD_PROCESS_INIT) a struct child_process variable; | |
27 | * 2. initializes the members; | |
28 | * 3. calls start_command(); | |
29 | * 4. processes the data; | |
30 | * 5. closes file descriptors (if necessary; see below); | |
31 | * 6. calls finish_command(). | |
32 | * | |
33 | * Special forms of redirection are available by setting these members | |
34 | * to 1: | |
35 | * | |
36 | * .no_stdin, .no_stdout, .no_stderr: The respective channel is | |
37 | * redirected to /dev/null. | |
38 | * | |
39 | * .stdout_to_stderr: stdout of the child is redirected to its | |
40 | * stderr. This happens after stderr is itself redirected. | |
41 | * So stdout will follow stderr to wherever it is | |
42 | * redirected. | |
43 | */ | |
f1000898 | 44 | struct child_process { |
4c4066d9 HW |
45 | |
46 | /** | |
47 | * The .argv member is set up as an array of string pointers (NULL | |
48 | * terminated), of which .argv[0] is the program name to run (usually | |
49 | * without a path). If the command to run is a git command, set argv[0] to | |
50 | * the command name without the 'git-' prefix and set .git_cmd = 1. | |
51 | * | |
52 | * Note that the ownership of the memory pointed to by .argv stays with the | |
53 | * caller, but it should survive until `finish_command` completes. If the | |
54 | * .argv member is NULL, `start_command` will point it at the .args | |
c972bf4c | 55 | * `strvec` (so you may use one or the other, but you must use exactly |
4c4066d9 HW |
56 | * one). The memory in .args will be cleaned up automatically during |
57 | * `finish_command` (or during `start_command` when it is unsuccessful). | |
58 | * | |
59 | */ | |
f1000898 | 60 | const char **argv; |
4c4066d9 | 61 | |
c972bf4c JK |
62 | struct strvec args; |
63 | struct strvec env_array; | |
ebcb5d16 | 64 | pid_t pid; |
ee4512ed JH |
65 | |
66 | int trace2_child_id; | |
67 | uint64_t trace2_child_us_start; | |
68 | const char *trace2_child_class; | |
69 | const char *trace2_hook_name; | |
70 | ||
c20181e3 JS |
71 | /* |
72 | * Using .in, .out, .err: | |
4c4066d9 HW |
73 | * - Specify 0 for no redirections. No new file descriptor is allocated. |
74 | * (child inherits stdin, stdout, stderr from parent). | |
c20181e3 JS |
75 | * - Specify -1 to have a pipe allocated as follows: |
76 | * .in: returns the writable pipe end; parent writes to it, | |
77 | * the readable pipe end becomes child's stdin | |
78 | * .out, .err: returns the readable pipe end; parent reads from | |
79 | * it, the writable pipe end becomes child's stdout/stderr | |
80 | * The caller of start_command() must close the returned FDs | |
81 | * after it has completed reading from/writing to it! | |
82 | * - Specify > 0 to set a channel to a particular FD as follows: | |
83 | * .in: a readable FD, becomes child's stdin | |
84 | * .out: a writable FD, becomes child's stdout/stderr | |
4f41b611 | 85 | * .err: a writable FD, becomes child's stderr |
c20181e3 JS |
86 | * The specified FD is closed by start_command(), even in case |
87 | * of errors! | |
88 | */ | |
4919bf03 | 89 | int in; |
f4bba25b | 90 | int out; |
f3b33f1d | 91 | int err; |
4c4066d9 HW |
92 | |
93 | /** | |
94 | * To specify a new initial working directory for the sub-process, | |
95 | * specify it in the .dir member. | |
96 | */ | |
1568fea0 | 97 | const char *dir; |
4c4066d9 HW |
98 | |
99 | /** | |
100 | * To modify the environment of the sub-process, specify an array of | |
101 | * string pointers (NULL terminated) in .env: | |
102 | * | |
103 | * - If the string is of the form "VAR=value", i.e. it contains '=' | |
104 | * the variable is added to the child process's environment. | |
105 | * | |
106 | * - If the string does not contain '=', it names an environment | |
107 | * variable that will be removed from the child process's environment. | |
108 | * | |
109 | * If the .env member is NULL, `start_command` will point it at the | |
c972bf4c | 110 | * .env_array `strvec` (so you may use one or the other, but not both). |
4c4066d9 HW |
111 | * The memory in .env_array will be cleaned up automatically during |
112 | * `finish_command` (or during `start_command` when it is unsuccessful). | |
113 | */ | |
ee493148 | 114 | const char *const *env; |
4c4066d9 | 115 | |
f1000898 | 116 | unsigned no_stdin:1; |
e4507ae8 | 117 | unsigned no_stdout:1; |
b73a4397 | 118 | unsigned no_stderr:1; |
539052f4 | 119 | unsigned git_cmd:1; /* if this is to be git sub-command */ |
4c4066d9 HW |
120 | |
121 | /** | |
122 | * If the program cannot be found, the functions return -1 and set | |
123 | * errno to ENOENT. Normally, an error message is printed, but if | |
124 | * .silent_exec_failure is set to 1, no message is printed for this | |
125 | * special error condition. | |
126 | */ | |
c024beb5 | 127 | unsigned silent_exec_failure:1; |
4c4066d9 | 128 | |
ee4e2255 JK |
129 | /** |
130 | * Run the command from argv[0] using a shell (but note that we may | |
131 | * still optimize out the shell call if the command contains no | |
132 | * metacharacters). Note that further arguments to the command in | |
133 | * argv[1], etc, do not need to be shell-quoted. | |
134 | */ | |
8dba1e63 | 135 | unsigned use_shell:1; |
ee4e2255 JK |
136 | |
137 | unsigned stdout_to_stderr:1; | |
afe19ff7 | 138 | unsigned clean_on_exit:1; |
46df6906 | 139 | unsigned wait_after_clean:1; |
ac2fbaa6 LS |
140 | void (*clean_on_exit_handler)(struct child_process *process); |
141 | void *clean_on_exit_handler_cbdata; | |
f1000898 SP |
142 | }; |
143 | ||
3d97ea47 ÆAB |
144 | #define CHILD_PROCESS_INIT { \ |
145 | .args = STRVEC_INIT, \ | |
146 | .env_array = STRVEC_INIT, \ | |
147 | } | |
4c4066d9 HW |
148 | |
149 | /** | |
150 | * The functions: child_process_init, start_command, finish_command, | |
151 | * run_command, run_command_v_opt, run_command_v_opt_cd_env, child_process_clear | |
152 | * do the following: | |
153 | * | |
154 | * - If a system call failed, errno is set and -1 is returned. A diagnostic | |
155 | * is printed. | |
156 | * | |
157 | * - If the program was not found, then -1 is returned and errno is set to | |
158 | * ENOENT; a diagnostic is printed only if .silent_exec_failure is 0. | |
159 | * | |
160 | * - Otherwise, the program is run. If it terminates regularly, its exit | |
161 | * code is returned. No diagnostic is printed, even if the exit code is | |
162 | * non-zero. | |
163 | * | |
164 | * - If the program terminated due to a signal, then the return value is the | |
165 | * signal number + 128, ie. the same value that a POSIX shell's $? would | |
166 | * report. A diagnostic is printed. | |
167 | * | |
168 | */ | |
169 | ||
170 | /** | |
171 | * Initialize a struct child_process variable. | |
172 | */ | |
483bbd4e | 173 | void child_process_init(struct child_process *); |
4c4066d9 HW |
174 | |
175 | /** | |
176 | * Release the memory associated with the struct child_process. | |
177 | * Most users of the run-command API don't need to call this | |
178 | * function explicitly because `start_command` invokes it on | |
179 | * failure and `finish_command` calls it automatically already. | |
180 | */ | |
2d71608e | 181 | void child_process_clear(struct child_process *); |
4c4066d9 | 182 | |
55454427 | 183 | int is_executable(const char *name); |
d3180279 | 184 | |
4c4066d9 HW |
185 | /** |
186 | * Start a sub-process. Takes a pointer to a `struct child_process` | |
187 | * that specifies the details and returns pipe FDs (if requested). | |
188 | * See below for details. | |
189 | */ | |
ebcb5d16 | 190 | int start_command(struct child_process *); |
4c4066d9 HW |
191 | |
192 | /** | |
193 | * Wait for the completion of a sub-process that was started with | |
194 | * start_command(). | |
195 | */ | |
ebcb5d16 | 196 | int finish_command(struct child_process *); |
4c4066d9 | 197 | |
507d7804 | 198 | int finish_command_in_signal(struct child_process *); |
4c4066d9 HW |
199 | |
200 | /** | |
201 | * A convenience function that encapsulates a sequence of | |
202 | * start_command() followed by finish_command(). Takes a pointer | |
203 | * to a `struct child_process` that specifies the details. | |
204 | */ | |
f1000898 SP |
205 | int run_command(struct child_process *); |
206 | ||
03f2c773 JK |
207 | /* |
208 | * Returns the path to the hook file, or NULL if the hook is missing | |
209 | * or disabled. Note that this points to static storage that will be | |
210 | * overwritten by further calls to find_hook and run_hook_*. | |
211 | */ | |
55454427 | 212 | const char *find_hook(const char *name); |
4c4066d9 HW |
213 | |
214 | /** | |
215 | * Run a hook. | |
216 | * The first argument is a pathname to an index file, or NULL | |
217 | * if the hook uses the default index file or no index is needed. | |
218 | * The second argument is the name of the hook. | |
219 | * The further arguments correspond to the hook arguments. | |
220 | * The last argument has to be NULL to terminate the arguments list. | |
221 | * If the hook does not exist or is not executable, the return | |
222 | * value will be zero. | |
223 | * If it is executable, the hook will be executed and the exit | |
224 | * status of the hook is returned. | |
225 | * On execution, .stdout_to_stderr and .no_stdin will be set. | |
226 | */ | |
9fe3edc4 | 227 | LAST_ARG_MUST_BE_NULL |
b199d714 | 228 | int run_hook_le(const char *const *env, const char *name, ...); |
55454427 | 229 | int run_hook_ve(const char *const *env, const char *name, va_list args); |
15048f8a | 230 | |
850b6ede JH |
231 | /* |
232 | * Trigger an auto-gc | |
233 | */ | |
a95ce124 | 234 | int run_auto_maintenance(int quiet); |
850b6ede | 235 | |
95d3c4f5 | 236 | #define RUN_COMMAND_NO_STDIN 1 |
77cb17e9 | 237 | #define RUN_GIT_CMD 2 /*If this is to be git sub-command */ |
cd83c74c | 238 | #define RUN_COMMAND_STDOUT_TO_STDERR 4 |
c024beb5 | 239 | #define RUN_SILENT_EXEC_FAILURE 8 |
8dba1e63 | 240 | #define RUN_USING_SHELL 16 |
10c6cddd | 241 | #define RUN_CLEAN_ON_EXIT 32 |
e662df7e | 242 | #define RUN_WAIT_AFTER_CLEAN 64 |
4c4066d9 HW |
243 | |
244 | /** | |
245 | * Convenience functions that encapsulate a sequence of | |
246 | * start_command() followed by finish_command(). The argument argv | |
247 | * specifies the program and its arguments. The argument opt is zero | |
248 | * or more of the flags `RUN_COMMAND_NO_STDIN`, `RUN_GIT_CMD`, | |
249 | * `RUN_COMMAND_STDOUT_TO_STDERR`, or `RUN_SILENT_EXEC_FAILURE` | |
250 | * that correspond to the members .no_stdin, .git_cmd, | |
251 | * .stdout_to_stderr, .silent_exec_failure of `struct child_process`. | |
252 | * The argument dir corresponds the member .dir. The argument env | |
253 | * corresponds to the member .env. | |
254 | */ | |
9b0b5093 | 255 | int run_command_v_opt(const char **argv, int opt); |
ee4512ed | 256 | int run_command_v_opt_tr2(const char **argv, int opt, const char *tr2_class); |
3427b375 AR |
257 | /* |
258 | * env (the environment) is to be formatted like environ: "VAR=VALUE". | |
259 | * To unset an environment variable use just "VAR". | |
260 | */ | |
ee493148 | 261 | int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env); |
ee4512ed JH |
262 | int run_command_v_opt_cd_env_tr2(const char **argv, int opt, const char *dir, |
263 | const char *const *env, const char *tr2_class); | |
b1bf95bb | 264 | |
911ec99b | 265 | /** |
96335bcf JK |
266 | * Execute the given command, sending "in" to its stdin, and capturing its |
267 | * stdout and stderr in the "out" and "err" strbufs. Any of the three may | |
268 | * be NULL to skip processing. | |
269 | * | |
911ec99b | 270 | * Returns -1 if starting the command fails or reading fails, and otherwise |
96335bcf JK |
271 | * returns the exit code of the command. Any output collected in the |
272 | * buffers is kept even if the command returns a non-zero exit. The hint fields | |
273 | * gives starting sizes for the strbuf allocations. | |
911ec99b JK |
274 | * |
275 | * The fields of "cmd" should be set up as they would for a normal run_command | |
96335bcf JK |
276 | * invocation. But note that there is no need to set the in, out, or err |
277 | * fields; pipe_command handles that automatically. | |
278 | */ | |
279 | int pipe_command(struct child_process *cmd, | |
280 | const char *in, size_t in_len, | |
281 | struct strbuf *out, size_t out_hint, | |
282 | struct strbuf *err, size_t err_hint); | |
283 | ||
284 | /** | |
285 | * Convenience wrapper around pipe_command for the common case | |
286 | * of capturing only stdout. | |
911ec99b | 287 | */ |
96335bcf JK |
288 | static inline int capture_command(struct child_process *cmd, |
289 | struct strbuf *out, | |
290 | size_t hint) | |
291 | { | |
292 | return pipe_command(cmd, NULL, 0, out, hint, NULL, 0); | |
293 | } | |
911ec99b | 294 | |
2d22c208 JS |
295 | /* |
296 | * The purpose of the following functions is to feed a pipe by running | |
297 | * a function asynchronously and providing output that the caller reads. | |
298 | * | |
299 | * It is expected that no synchronization and mutual exclusion between | |
300 | * the caller and the feed function is necessary so that the function | |
301 | * can run in a thread without interfering with the caller. | |
4c4066d9 HW |
302 | * |
303 | * The caller: | |
304 | * | |
305 | * 1. allocates and clears (memset(&asy, 0, sizeof(asy));) a | |
306 | * struct async variable; | |
307 | * 2. initializes .proc and .data; | |
308 | * 3. calls start_async(); | |
309 | * 4. processes communicates with proc through .in and .out; | |
310 | * 5. closes .in and .out; | |
311 | * 6. calls finish_async(). | |
312 | * | |
313 | * There are serious restrictions on what the asynchronous function can do | |
314 | * because this facility is implemented by a thread in the same address | |
315 | * space on most platforms (when pthreads is available), but by a pipe to | |
316 | * a forked process otherwise: | |
317 | * | |
318 | * - It cannot change the program's state (global variables, environment, | |
319 | * etc.) in a way that the caller notices; in other words, .in and .out | |
320 | * are the only communication channels to the caller. | |
321 | * | |
322 | * - It must not change the program's state that the caller of the | |
323 | * facility also uses. | |
324 | * | |
2d22c208 JS |
325 | */ |
326 | struct async { | |
4c4066d9 HW |
327 | |
328 | /** | |
329 | * The function pointer in .proc has the following signature: | |
330 | * | |
331 | * int proc(int in, int out, void *data); | |
332 | * | |
333 | * - in, out specifies a set of file descriptors to which the function | |
334 | * must read/write the data that it needs/produces. The function | |
335 | * *must* close these descriptors before it returns. A descriptor | |
336 | * may be -1 if the caller did not configure a descriptor for that | |
337 | * direction. | |
338 | * | |
339 | * - data is the value that the caller has specified in the .data member | |
340 | * of struct async. | |
341 | * | |
342 | * - The return value of the function is 0 on success and non-zero | |
343 | * on failure. If the function indicates failure, finish_async() will | |
344 | * report failure as well. | |
345 | * | |
2d22c208 | 346 | */ |
ae6a5609 | 347 | int (*proc)(int in, int out, void *data); |
4c4066d9 | 348 | |
2d22c208 | 349 | void *data; |
4c4066d9 HW |
350 | |
351 | /** | |
352 | * The members .in, .out are used to provide a set of fd's for | |
353 | * communication between the caller and the callee as follows: | |
354 | * | |
355 | * - Specify 0 to have no file descriptor passed. The callee will | |
356 | * receive -1 in the corresponding argument. | |
357 | * | |
358 | * - Specify < 0 to have a pipe allocated; start_async() replaces | |
359 | * with the pipe FD in the following way: | |
360 | * | |
361 | * .in: Returns the writable pipe end into which the caller | |
362 | * writes; the readable end of the pipe becomes the function's | |
363 | * in argument. | |
364 | * | |
365 | * .out: Returns the readable pipe end from which the caller | |
366 | * reads; the writable end of the pipe becomes the function's | |
367 | * out argument. | |
368 | * | |
369 | * The caller of start_async() must close the returned FDs after it | |
370 | * has completed reading from/writing from them. | |
371 | * | |
372 | * - Specify a file descriptor > 0 to be used by the function: | |
373 | * | |
374 | * .in: The FD must be readable; it becomes the function's in. | |
375 | * .out: The FD must be writable; it becomes the function's out. | |
376 | * | |
377 | * The specified FD is closed by start_async(), even if it fails to | |
378 | * run the function. | |
379 | */ | |
ae6a5609 | 380 | int in; /* caller writes here and closes it */ |
2d22c208 | 381 | int out; /* caller reads from here and closes it */ |
f6b60983 | 382 | #ifdef NO_PTHREADS |
2d22c208 | 383 | pid_t pid; |
618ebe9f | 384 | #else |
200a76b7 | 385 | pthread_t tid; |
ae6a5609 EFL |
386 | int proc_in; |
387 | int proc_out; | |
618ebe9f | 388 | #endif |
c792d7b6 | 389 | int isolate_sigpipe; |
2d22c208 JS |
390 | }; |
391 | ||
4c4066d9 HW |
392 | /** |
393 | * Run a function asynchronously. Takes a pointer to a `struct | |
394 | * async` that specifies the details and returns a set of pipe FDs | |
395 | * for communication with the function. See below for details. | |
396 | */ | |
2d22c208 | 397 | int start_async(struct async *async); |
4c4066d9 HW |
398 | |
399 | /** | |
400 | * Wait for the completion of an asynchronous function that was | |
401 | * started with start_async(). | |
402 | */ | |
2d22c208 | 403 | int finish_async(struct async *async); |
4c4066d9 | 404 | |
661a8cf4 | 405 | int in_async(void); |
c0e40a2d | 406 | int async_with_fork(void); |
b992fe10 | 407 | void check_pipe(int err); |
2d22c208 | 408 | |
c553c72e SB |
409 | /** |
410 | * This callback should initialize the child process and preload the | |
411 | * error channel if desired. The preloading of is useful if you want to | |
412 | * have a message printed directly before the output of the child process. | |
413 | * pp_cb is the callback cookie as passed to run_processes_parallel. | |
414 | * You can store a child process specific callback cookie in pp_task_cb. | |
415 | * | |
416 | * Even after returning 0 to indicate that there are no more processes, | |
417 | * this function will be called again until there are no more running | |
418 | * child processes. | |
419 | * | |
420 | * Return 1 if the next child is ready to run. | |
421 | * Return 0 if there are currently no more tasks to be processed. | |
422 | * To send a signal to other child processes for abortion, | |
423 | * return the negative signal number. | |
424 | */ | |
425 | typedef int (*get_next_task_fn)(struct child_process *cp, | |
aa710494 | 426 | struct strbuf *out, |
c553c72e SB |
427 | void *pp_cb, |
428 | void **pp_task_cb); | |
429 | ||
430 | /** | |
431 | * This callback is called whenever there are problems starting | |
432 | * a new process. | |
433 | * | |
434 | * You must not write to stdout or stderr in this function. Add your | |
aa710494 | 435 | * message to the strbuf out instead, which will be printed without |
c553c72e SB |
436 | * messing up the output of the other parallel processes. |
437 | * | |
438 | * pp_cb is the callback cookie as passed into run_processes_parallel, | |
439 | * pp_task_cb is the callback cookie as passed into get_next_task_fn. | |
440 | * | |
441 | * Return 0 to continue the parallel processing. To abort return non zero. | |
442 | * To send a signal to other child processes for abortion, return | |
443 | * the negative signal number. | |
444 | */ | |
aa710494 | 445 | typedef int (*start_failure_fn)(struct strbuf *out, |
c553c72e SB |
446 | void *pp_cb, |
447 | void *pp_task_cb); | |
448 | ||
449 | /** | |
450 | * This callback is called on every child process that finished processing. | |
451 | * | |
452 | * You must not write to stdout or stderr in this function. Add your | |
aa710494 | 453 | * message to the strbuf out instead, which will be printed without |
c553c72e SB |
454 | * messing up the output of the other parallel processes. |
455 | * | |
456 | * pp_cb is the callback cookie as passed into run_processes_parallel, | |
457 | * pp_task_cb is the callback cookie as passed into get_next_task_fn. | |
458 | * | |
459 | * Return 0 to continue the parallel processing. To abort return non zero. | |
460 | * To send a signal to other child processes for abortion, return | |
461 | * the negative signal number. | |
462 | */ | |
463 | typedef int (*task_finished_fn)(int result, | |
aa710494 | 464 | struct strbuf *out, |
c553c72e SB |
465 | void *pp_cb, |
466 | void *pp_task_cb); | |
467 | ||
468 | /** | |
469 | * Runs up to n processes at the same time. Whenever a process can be | |
470 | * started, the callback get_next_task_fn is called to obtain the data | |
471 | * required to start another child process. | |
472 | * | |
473 | * The children started via this function run in parallel. Their output | |
474 | * (both stdout and stderr) is routed to stderr in a manner that output | |
475 | * from different tasks does not interleave. | |
476 | * | |
2a73b3da SB |
477 | * start_failure_fn and task_finished_fn can be NULL to omit any |
478 | * special handling. | |
c553c72e SB |
479 | */ |
480 | int run_processes_parallel(int n, | |
481 | get_next_task_fn, | |
482 | start_failure_fn, | |
483 | task_finished_fn, | |
484 | void *pp_cb); | |
ee4512ed JH |
485 | int run_processes_parallel_tr2(int n, get_next_task_fn, start_failure_fn, |
486 | task_finished_fn, void *pp_cb, | |
487 | const char *tr2_category, const char *tr2_label); | |
c553c72e | 488 | |
d1fa9435 JT |
489 | /** |
490 | * Convenience function which prepares env_array for a command to be run in a | |
491 | * new repo. This adds all GIT_* environment variables to env_array with the | |
492 | * exception of GIT_CONFIG_PARAMETERS and GIT_CONFIG_COUNT (which cause the | |
493 | * corresponding environment variables to be unset in the subprocess) and adds | |
494 | * an environment variable pointing to new_git_dir. See local_repo_env in | |
495 | * cache.h for more information. | |
496 | */ | |
497 | void prepare_other_repo_env(struct strvec *env_array, const char *new_git_dir); | |
498 | ||
b1bf95bb | 499 | #endif |