This file is indexed.

/usr/include/pipeline.h is in libpipeline-dev 1.2.1-1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
/* Copyright (C) 1989, 1990, 1991, 1992, 2000, 2002
 * Free Software Foundation, Inc.
 * Copyright (C) 2003, 2004, 2005, 2007, 2008 Colin Watson.
 *   Written for groff by James Clark (jjc@jclark.com)
 *   Adapted for man-db by Colin Watson.
 *
 * This file is part of libpipeline.
 *
 * libpipeline is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * libpipeline is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with libpipeline; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301
 * USA.
 */

#ifndef PIPELINE_H
#define PIPELINE_H

#ifdef __cplusplus
extern "C" {
#endif

#include <stdio.h>
#include <stdarg.h>
#include <sys/types.h>

/* GCC version checking borrowed from glibc. */
#if defined(__GNUC__) && defined(__GNUC_MINOR__)
#  define PIPELINE_GNUC_PREREQ(maj,min) \
	((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
#else
#  define PIPELINE_GNUC_PREREQ(maj,min) 0
#endif

/* Does this compiler support format string checking? */
#if PIPELINE_GNUC_PREREQ(2,0)
#  define PIPELINE_ATTR_FORMAT_PRINTF(a,b) \
	__attribute__ ((__format__ (__printf__, a, b)))
#else
#  define PIPELINE_ATTR_FORMAT_PRINTF(a,b)
#endif

/* Does this compiler support marking variables as unused? */
#if PIPELINE_GNUC_PREREQ(2,4)
#  define PIPELINE_ATTR_UNUSED __attribute__ ((__unused__))
#else
#  define PIPELINE_ATTR_UNUSED
#endif

/* Does this compiler support marking functions as non-returning? */
#if PIPELINE_GNUC_PREREQ(2,5)
#  define PIPELINE_ATTR_NORETURN __attribute__ ((__noreturn__))
#else
#  define PIPELINE_ATTR_NORETURN
#endif

/* Does this compiler support unused result checking? */
#if PIPELINE_GNUC_PREREQ(3,4)
#  define PIPELINE_ATTR_WARN_UNUSED_RESULT \
	__attribute__ ((__warn_unused_result__))
#else
#  define PIPELINE_ATTR_WARN_UNUSED_RESULT
#endif

/* Does this compiler support sentinel checking? */
#if PIPELINE_GNUC_PREREQ(4,0)
#  define PIPELINE_ATTR_SENTINEL __attribute__ ((__sentinel__))
#else
#  define PIPELINE_ATTR_SENTINEL
#endif

typedef void pipecmd_function_type (void *);
typedef void pipecmd_function_free_type (void *);

struct pipecmd;
typedef struct pipecmd pipecmd;

struct pipeline;
typedef struct pipeline pipeline;

/* ---------------------------------------------------------------------- */

/* Functions to build individual commands. */

/* Construct a new command. */
pipecmd *pipecmd_new (const char *name);

/* Convenience constructors wrapping pipecmd_new() and pipecmd_arg().
 * Terminate arguments with NULL.
 */
pipecmd *pipecmd_new_argv (const char *name, va_list argv);
pipecmd *pipecmd_new_args (const char *name, ...) PIPELINE_ATTR_SENTINEL;

/* Split argstr on whitespace to construct a command and arguments,
 * honouring shell-style single-quoting, double-quoting, and backslashes,
 * but not other shell evil like wildcards, semicolons, or backquotes. This
 * is a backward-compatibility hack to support old configuration file
 * directives; please try to avoid using it in new code.
 */
pipecmd *pipecmd_new_argstr (const char *argstr);

/* Construct a new command that calls a given function rather than executing
 * a process. The data argument is passed as the function's only argument,
 * and will be freed before returning using free_func (if non-NULL).
 *
 * pipecmd_* functions that deal with arguments cannot be used with the
 * command returned by this function.
 */
pipecmd *pipecmd_new_function (const char *name,
			       pipecmd_function_type *func,
			       pipecmd_function_free_type *free_func,
			       void *data);

/* Construct a new command that runs a sequence of commands. The commands
 * will be executed in forked children; if any exits non-zero then it will
 * terminate the sequence, as with "&&" in shell.
 *
 * pipecmd_* functions that deal with arguments cannot be used with the
 * command returned by this function.
 */
pipecmd *pipecmd_new_sequencev (const char *name, va_list cmdv);
pipecmd *pipecmd_new_sequence (const char *name, ...) PIPELINE_ATTR_SENTINEL;

/* Return a new command that just passes data from its input to its output. */
pipecmd *pipecmd_new_passthrough (void);

/* Return a duplicate of a command. */
pipecmd *pipecmd_dup (pipecmd *cmd);

/* Add an argument to a command. */
void pipecmd_arg (pipecmd *cmd, const char *arg);

/* Convenience function to add an argument with printf substitutions. */
void pipecmd_argf (pipecmd *cmd, const char *format, ...)
	PIPELINE_ATTR_FORMAT_PRINTF(2, 3);

/* Convenience functions wrapping pipecmd_arg().
 * Terminate arguments with NULL.
 */
void pipecmd_argv (pipecmd *cmd, va_list argv);
void pipecmd_args (pipecmd *cmd, ...) PIPELINE_ATTR_SENTINEL;

/* Split argstr on whitespace to add a list of arguments, honouring
 * shell-style single-quoting, double-quoting, and backslashes, but not
 * other shell evil like wildcards, semicolons, or backquotes. This is a
 * backward-compatibility hack to support old configuration file directives;
 * please try to avoid using it in new code.
 */
void pipecmd_argstr (pipecmd *cmd, const char *argstr);

/* Return the number of arguments to this command.  Note that this includes
 * the command name as the first argument, so the command 'echo foo bar' is
 * counted as having three arguments.
 */
int pipecmd_get_nargs (pipecmd *cmd);

/* Set the nice(3) value for this command.  Defaults to 0.  Errors while
 * attempting to set the nice value are ignored, aside from emitting a debug
 * message.
 */
void pipecmd_nice (pipecmd *cmd, int nice);

/* If discard_err is non-zero, redirect this command's standard error to
 * /dev/null.  Otherwise, and by default, pass it through.
 */
void pipecmd_discard_err (pipecmd *cmd, int discard_err);

/* Set an environment variable while running this command. */
void pipecmd_setenv (pipecmd *cmd, const char *name, const char *value);

/* Unset an environment variable while running this command. */
void pipecmd_unsetenv (pipecmd *cmd, const char *name);

/* Clear the environment while running this command.  (Note that environment
 * operations work in sequence; pipecmd_clearenv followed by pipecmd_setenv
 * causes the command to have just a single environment variable set.)
 */
void pipecmd_clearenv (pipecmd *cmd);

/* Add a command to a sequence. */
void pipecmd_sequence_command (pipecmd *cmd, pipecmd *child);

/* Dump a string representation of a command to stream. */
void pipecmd_dump (pipecmd *cmd, FILE *stream);

/* Return a string representation of a command. The caller should free the
 * result.
 */
char *pipecmd_tostring (pipecmd *cmd);

/* Execute a single command, replacing the current process.  Never returns,
 * instead exiting non-zero on failure.
 */
void pipecmd_exec (pipecmd *cmd) PIPELINE_ATTR_NORETURN;

/* Destroy a command. Safely does nothing on NULL. */
void pipecmd_free (pipecmd *cmd);

/* ---------------------------------------------------------------------- */

/* Functions to build pipelines. */

/* Construct a new pipeline. */
pipeline *pipeline_new (void);

/* Convenience constructors wrapping pipeline_new() and pipeline_command().
 * Terminate commands with NULL.
 */
pipeline *pipeline_new_commandv (pipecmd *cmd1, va_list cmdv);
pipeline *pipeline_new_commands (pipecmd *cmd1, ...) PIPELINE_ATTR_SENTINEL;

/* Construct a new pipeline and add a single command to it. */
pipeline *pipeline_new_command_argv (const char *name, va_list argv);
pipeline *pipeline_new_command_args (const char *name, ...)
	PIPELINE_ATTR_SENTINEL;

/* Joins two pipelines, neither of which are allowed to be started. Discards
 * want_out, want_outfile, and outfd from p1, and want_in, want_infile, and
 * infd from p2.
 */
pipeline *pipeline_join (pipeline *p1, pipeline *p2);

/* Connect the input of one or more sink pipelines to the output of a source
 * pipeline. The source pipeline may be started, but in that case want_out
 * must be negative; otherwise, discards want_out from source. In any event,
 * discards want_in from all sinks, none of which are allowed to be started.
 * Terminate arguments with NULL.
 *
 * This is an application-level connection; data may be intercepted between
 * the pipelines by the program before calling pipeline_pump(), which sets
 * data flowing from the source to the sinks. It is primarily useful when
 * more than one sink pipeline is involved, in which case the pipelines
 * cannot simply be concatenated into one.
 */
void pipeline_connect (pipeline *source, pipeline *sink, ...)
	PIPELINE_ATTR_SENTINEL;

/* Add a command to a pipeline. */
void pipeline_command (pipeline *p, pipecmd *cmd);

/* Construct a new command and add it to a pipeline in one go. */
void pipeline_command_argv (pipeline *p, const char *name, va_list argv);
void pipeline_command_args (pipeline *p, const char *name, ...)
	PIPELINE_ATTR_SENTINEL;

/* Construct a new command from a shell-quoted string and add it to a
 * pipeline in one go. See the comment against pipecmd_new_argstr() above if
 * you're tempted to use this function.
 */
void pipeline_command_argstr (pipeline *p, const char *argstr);

/* Convenience functions wrapping pipeline_command().
 * Terminate commands with NULL.
 */
void pipeline_commandv (pipeline *p, va_list cmdv);
void pipeline_commands (pipeline *p, ...) PIPELINE_ATTR_SENTINEL;

/* Return the number of commands in this pipeline. */
int pipeline_get_ncommands (pipeline *p);

/* Return command number n from this pipeline, counting from zero, or NULL
 * if n is out of range.
 */
pipecmd *pipeline_get_command (pipeline *p, int n);

/* Set command number n in this pipeline, counting from zero, to cmd, and
 * return the previous command in that position.  Do nothing and return NULL
 * if n is out of range.
 */
pipecmd *pipeline_set_command (pipeline *p, int n, pipecmd *cmd);

/* Return the process ID of command number n from this pipeline, counting
 * from zero.  The pipeline must be started.  Return -1 if n is out of range
 * or if the command has already exited and been reaped.
 */
pid_t pipeline_get_pid (pipeline *p, int n);

/* Set file descriptors to use as the input and output of the whole
 * pipeline.  If non-negative, fd is used directly as a file descriptor.  If
 * negative, pipeline_start will create pipes and store the input writing
 * half and the output reading half in the pipeline's infd or outfd field as
 * appropriate.  The default is to leave input and output as stdin and
 * stdout unless pipeline_want_infile or pipeline_want_outfile respectively
 * has been called.
 *
 * Calling these functions supersedes any previous call to
 * pipeline_want_infile or pipeline_want_outfile respectively.
 */
void pipeline_want_in (pipeline *p, int fd);
void pipeline_want_out (pipeline *p, int fd);

/* Set file names to open and use as the input and output of the whole
 * pipeline.  This may be more convenient than supplying file descriptors,
 * and guarantees that the files are opened with the same privileges under
 * which the pipeline is run.
 *
 * Calling these functions (even with NULL, which returns to the default of
 * leaving input and output as stdin and stdout) supersedes any previous
 * call to pipeline_want_in or pipeline_want_outfile respectively.
 *
 * The given files will be opened when the pipeline is started.  If an
 * output file does not already exist, it is created (with mode 0666
 * modified in the usual way by umask); if it does exist, then it is
 * truncated.
 */
void pipeline_want_infile (pipeline *p, const char *file);
void pipeline_want_outfile (pipeline *p, const char *file);

/* If ignore_signals is non-zero (which is the default), ignore SIGINT and
 * SIGQUIT while the pipeline is running, like system().  Otherwise, leave
 * their dispositions unchanged.
 */
void pipeline_ignore_signals (pipeline *p, int ignore_signals);

/* Get streams corresponding to infd and outfd respectively. The pipeline
 * must be started.
 */
FILE *pipeline_get_infile (pipeline *p);
FILE *pipeline_get_outfile (pipeline *p);

/* Dump a string representation of p to stream. */
void pipeline_dump (pipeline *p, FILE *stream);

/* Return a string representation of p. The caller should free the result. */
char *pipeline_tostring (pipeline *p);

/* Destroy a pipeline and all its commands. Safely does nothing on NULL.
 * May wait for the pipeline to complete if it has not already done so.
 */
void pipeline_free (pipeline *p);

/* ---------------------------------------------------------------------- */

/* Functions to run pipelines and handle signals. */

typedef void pipeline_post_fork_fn (void);

/* Install a post-fork handler.  This will be run in any child process
 * immediately after it is forked.  For instance, this may be used for
 * cleaning up application-specific signal handlers.  Pass NULL to clear any
 * existing post-fork handler.
 */
void pipeline_install_post_fork (pipeline_post_fork_fn *fn);

/* Start the processes in a pipeline. Installs this library's SIGCHLD
 * handler if not already installed. Calls error(FATAL) on error. */
void pipeline_start (pipeline *p);

/* Wait for a pipeline to complete.  Set *statuses to a newly-allocated
 * array of wait statuses, as returned by waitpid, and *n_statuses to the
 * length of that array.  The return value is similar to the exit status
 * that a shell would return, with some modifications.  If the last command
 * exits with a signal (other than SIGPIPE, which is considered equivalent
 * to exiting zero), then the return value is 128 plus the signal number; if
 * the last command exits normally but non-zero, then the return value is
 * its exit status; if any other command exits non-zero, then the return
 * value is 127; otherwise, the return value is 0.  This means that the
 * return value is only 0 if all commands in the pipeline exit successfully.
 */
int pipeline_wait_all (pipeline *p, int **statuses, int *n_statuses);

/* Wait for a pipeline to complete and return its combined exit status,
 * calculated as for pipeline_wait_all().
 */
int pipeline_wait (pipeline *p);

/* Start a pipeline, wait for it to complete, and free it, all in one go. */
int pipeline_run (pipeline *p);

/* Pump data among one or more pipelines connected using pipeline_connect()
 * until all source pipelines have reached end-of-file and all data has been
 * written to all sinks (or failed). All relevant pipelines must be
 * supplied: that is, no pipeline that has been connected to a source
 * pipeline may be supplied unless that source pipeline is also supplied.
 * Automatically starts all pipelines if they are not already started, but
 * does not wait for them. Terminate arguments with NULL.
 */
void pipeline_pump (pipeline *p, ...) PIPELINE_ATTR_SENTINEL;

/* ---------------------------------------------------------------------- */

/* Functions to read output from pipelines. */

/* Read len bytes of data from the pipeline, returning the data block. len
 * is updated with the number of bytes read.
 */
const char *pipeline_read (pipeline *p, size_t *len);

/* Look ahead in the pipeline's output for len bytes of data, returning the
 * data block. len is updated with the number of bytes read. The starting
 * position of the next read or peek is not affected by this call.
 */
const char *pipeline_peek (pipeline *p, size_t *len);

/* Return the number of bytes of data that can be read using pipeline_read
 * or pipeline_peek solely from the peek cache, without having to read from
 * the pipeline itself (and thus potentially block).
 */
size_t pipeline_peek_size (pipeline *p);

/* Skip over and discard len bytes of data from the peek cache. Asserts that
 * enough data is available to skip, so you may want to check using
 * pipeline_peek_size first.
 */
void pipeline_peek_skip (pipeline *p, size_t len);

/* Read a line of data from the pipeline, returning it. */
const char *pipeline_readline (pipeline *p);

/* Look ahead in the pipeline's output for a line of data, returning it. The
 * starting position of the next read or peek is not affected by this call.
 */
const char *pipeline_peekline (pipeline *p);

#ifdef __cplusplus
}
#endif

#endif /* PIPELINE_H */