Merge branch 'sg/t-helper-gitignore'
[git/git.git] / run-command.h
1 #ifndef RUN_COMMAND_H
2 #define RUN_COMMAND_H
3
4 #include "thread-utils.h"
5
6 #include "argv-array.h"
7
8 struct child_process {
9 const char **argv;
10 struct argv_array args;
11 struct argv_array env_array;
12 pid_t pid;
13
14 int trace2_child_id;
15 uint64_t trace2_child_us_start;
16 const char *trace2_child_class;
17 const char *trace2_hook_name;
18
19 /*
20 * Using .in, .out, .err:
21 * - Specify 0 for no redirections (child inherits stdin, stdout,
22 * stderr from parent).
23 * - Specify -1 to have a pipe allocated as follows:
24 * .in: returns the writable pipe end; parent writes to it,
25 * the readable pipe end becomes child's stdin
26 * .out, .err: returns the readable pipe end; parent reads from
27 * it, the writable pipe end becomes child's stdout/stderr
28 * The caller of start_command() must close the returned FDs
29 * after it has completed reading from/writing to it!
30 * - Specify > 0 to set a channel to a particular FD as follows:
31 * .in: a readable FD, becomes child's stdin
32 * .out: a writable FD, becomes child's stdout/stderr
33 * .err: a writable FD, becomes child's stderr
34 * The specified FD is closed by start_command(), even in case
35 * of errors!
36 */
37 int in;
38 int out;
39 int err;
40 const char *dir;
41 const char *const *env;
42 unsigned no_stdin:1;
43 unsigned no_stdout:1;
44 unsigned no_stderr:1;
45 unsigned git_cmd:1; /* if this is to be git sub-command */
46 unsigned silent_exec_failure:1;
47 unsigned stdout_to_stderr:1;
48 unsigned use_shell:1;
49 unsigned clean_on_exit:1;
50 unsigned wait_after_clean:1;
51 void (*clean_on_exit_handler)(struct child_process *process);
52 void *clean_on_exit_handler_cbdata;
53 };
54
55 #define CHILD_PROCESS_INIT { NULL, ARGV_ARRAY_INIT, ARGV_ARRAY_INIT }
56 void child_process_init(struct child_process *);
57 void child_process_clear(struct child_process *);
58 int is_executable(const char *name);
59
60 int start_command(struct child_process *);
61 int finish_command(struct child_process *);
62 int finish_command_in_signal(struct child_process *);
63 int run_command(struct child_process *);
64
65 /*
66 * Returns the path to the hook file, or NULL if the hook is missing
67 * or disabled. Note that this points to static storage that will be
68 * overwritten by further calls to find_hook and run_hook_*.
69 */
70 const char *find_hook(const char *name);
71 LAST_ARG_MUST_BE_NULL
72 int run_hook_le(const char *const *env, const char *name, ...);
73 int run_hook_ve(const char *const *env, const char *name, va_list args);
74
75 #define RUN_COMMAND_NO_STDIN 1
76 #define RUN_GIT_CMD 2 /*If this is to be git sub-command */
77 #define RUN_COMMAND_STDOUT_TO_STDERR 4
78 #define RUN_SILENT_EXEC_FAILURE 8
79 #define RUN_USING_SHELL 16
80 #define RUN_CLEAN_ON_EXIT 32
81 int run_command_v_opt(const char **argv, int opt);
82 int run_command_v_opt_tr2(const char **argv, int opt, const char *tr2_class);
83 /*
84 * env (the environment) is to be formatted like environ: "VAR=VALUE".
85 * To unset an environment variable use just "VAR".
86 */
87 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env);
88 int run_command_v_opt_cd_env_tr2(const char **argv, int opt, const char *dir,
89 const char *const *env, const char *tr2_class);
90
91 /**
92 * Execute the given command, sending "in" to its stdin, and capturing its
93 * stdout and stderr in the "out" and "err" strbufs. Any of the three may
94 * be NULL to skip processing.
95 *
96 * Returns -1 if starting the command fails or reading fails, and otherwise
97 * returns the exit code of the command. Any output collected in the
98 * buffers is kept even if the command returns a non-zero exit. The hint fields
99 * gives starting sizes for the strbuf allocations.
100 *
101 * The fields of "cmd" should be set up as they would for a normal run_command
102 * invocation. But note that there is no need to set the in, out, or err
103 * fields; pipe_command handles that automatically.
104 */
105 int pipe_command(struct child_process *cmd,
106 const char *in, size_t in_len,
107 struct strbuf *out, size_t out_hint,
108 struct strbuf *err, size_t err_hint);
109
110 /**
111 * Convenience wrapper around pipe_command for the common case
112 * of capturing only stdout.
113 */
114 static inline int capture_command(struct child_process *cmd,
115 struct strbuf *out,
116 size_t hint)
117 {
118 return pipe_command(cmd, NULL, 0, out, hint, NULL, 0);
119 }
120
121 /*
122 * The purpose of the following functions is to feed a pipe by running
123 * a function asynchronously and providing output that the caller reads.
124 *
125 * It is expected that no synchronization and mutual exclusion between
126 * the caller and the feed function is necessary so that the function
127 * can run in a thread without interfering with the caller.
128 */
129 struct async {
130 /*
131 * proc reads from in; closes it before return
132 * proc writes to out; closes it before return
133 * returns 0 on success, non-zero on failure
134 */
135 int (*proc)(int in, int out, void *data);
136 void *data;
137 int in; /* caller writes here and closes it */
138 int out; /* caller reads from here and closes it */
139 #ifdef NO_PTHREADS
140 pid_t pid;
141 #else
142 pthread_t tid;
143 int proc_in;
144 int proc_out;
145 #endif
146 int isolate_sigpipe;
147 };
148
149 int start_async(struct async *async);
150 int finish_async(struct async *async);
151 int in_async(void);
152 int async_with_fork(void);
153 void check_pipe(int err);
154
155 /**
156 * This callback should initialize the child process and preload the
157 * error channel if desired. The preloading of is useful if you want to
158 * have a message printed directly before the output of the child process.
159 * pp_cb is the callback cookie as passed to run_processes_parallel.
160 * You can store a child process specific callback cookie in pp_task_cb.
161 *
162 * Even after returning 0 to indicate that there are no more processes,
163 * this function will be called again until there are no more running
164 * child processes.
165 *
166 * Return 1 if the next child is ready to run.
167 * Return 0 if there are currently no more tasks to be processed.
168 * To send a signal to other child processes for abortion,
169 * return the negative signal number.
170 */
171 typedef int (*get_next_task_fn)(struct child_process *cp,
172 struct strbuf *out,
173 void *pp_cb,
174 void **pp_task_cb);
175
176 /**
177 * This callback is called whenever there are problems starting
178 * a new process.
179 *
180 * You must not write to stdout or stderr in this function. Add your
181 * message to the strbuf out instead, which will be printed without
182 * messing up the output of the other parallel processes.
183 *
184 * pp_cb is the callback cookie as passed into run_processes_parallel,
185 * pp_task_cb is the callback cookie as passed into get_next_task_fn.
186 *
187 * Return 0 to continue the parallel processing. To abort return non zero.
188 * To send a signal to other child processes for abortion, return
189 * the negative signal number.
190 */
191 typedef int (*start_failure_fn)(struct strbuf *out,
192 void *pp_cb,
193 void *pp_task_cb);
194
195 /**
196 * This callback is called on every child process that finished processing.
197 *
198 * You must not write to stdout or stderr in this function. Add your
199 * message to the strbuf out instead, which will be printed without
200 * messing up the output of the other parallel processes.
201 *
202 * pp_cb is the callback cookie as passed into run_processes_parallel,
203 * pp_task_cb is the callback cookie as passed into get_next_task_fn.
204 *
205 * Return 0 to continue the parallel processing. To abort return non zero.
206 * To send a signal to other child processes for abortion, return
207 * the negative signal number.
208 */
209 typedef int (*task_finished_fn)(int result,
210 struct strbuf *out,
211 void *pp_cb,
212 void *pp_task_cb);
213
214 /**
215 * Runs up to n processes at the same time. Whenever a process can be
216 * started, the callback get_next_task_fn is called to obtain the data
217 * required to start another child process.
218 *
219 * The children started via this function run in parallel. Their output
220 * (both stdout and stderr) is routed to stderr in a manner that output
221 * from different tasks does not interleave.
222 *
223 * start_failure_fn and task_finished_fn can be NULL to omit any
224 * special handling.
225 */
226 int run_processes_parallel(int n,
227 get_next_task_fn,
228 start_failure_fn,
229 task_finished_fn,
230 void *pp_cb);
231 int run_processes_parallel_tr2(int n, get_next_task_fn, start_failure_fn,
232 task_finished_fn, void *pp_cb,
233 const char *tr2_category, const char *tr2_label);
234
235 #endif