1 .TH MAKE 1 "31 May 2022" "GNU" "User Commands"
3 make \- GNU make utility to maintain groups of programs
6 [\fIOPTION\fR]... [\fITARGET\fR]...
11 utility will determine automatically which pieces of a large program need to
12 be recompiled, and issue the commands to recompile them. The manual describes
13 the GNU implementation of
15 which was written by Richard Stallman and Roland McGrath, and is currently
16 maintained by Paul Smith. Our examples show C programs, since they are very
17 common, but you can use
19 with any programming language whose compiler can be run with a shell command.
22 is not limited to programs. You can use it to describe any task where some
23 files must be updated automatically from others whenever the others change.
27 you must write a file called the
29 that describes the relationships among files in your program, and provides
30 commands for updating each file. In a program, typically the executable file
31 is updated from object files, which are in turn made by compiling source
34 Once a suitable makefile exists, each time you change some source files,
35 this simple shell command:
41 suffices to perform all necessary recompilations.
44 program uses the makefile description and the last-modification times of the
45 files to decide which of the files need to be updated. For each of those
46 files, it issues the commands recorded in the makefile.
49 executes commands in the
55 is typically a program.
60 will look for the makefiles
67 Normally you should call your makefile either
73 because it appears prominently near the beginning of a directory
74 listing, right near other important files such as
76 The first name checked,
78 is not recommended for most makefiles. You should use this name if you have a
79 makefile that is specific to GNU
81 and will not be understood by other versions of
85 is '\-', the standard input is read.
88 updates a target if it depends on prerequisite files
89 that have been modified since the target was last modified,
90 or if the target does not exist.
95 These options are ignored for compatibility with other versions of
98 \fB\-B\fR, \fB\-\-always\-make\fR
99 Unconditionally make all targets.
101 \fB\-C\fR \fIdir\fR, \fB\-\-directory\fR=\fIdir\fR
104 before reading the makefiles or doing anything else.
107 options are specified, each is interpreted relative to the
113 This is typically used with recursive invocations of
117 Print debugging information in addition to normal processing.
118 The debugging information says which files are being considered for
119 remaking, which file-times are being compared and with what results,
120 which files actually need to be remade, which implicit rules are
121 considered and which are applied---everything interesting about how
125 .BI \-\-debug "[=FLAGS]"
126 Print debugging information in addition to normal processing.
129 are omitted, then the behavior is the same as if
133 may be any or all of the following names, comma- or space-separated. Only the
134 first character is significant: the rest may be omitted:
136 for all debugging output (same as using
141 for more verbose basic debugging,
143 for showing implicit rule search operations,
145 for details on invocation of commands,
147 for debugging while remaking makefiles,
149 shows all recipes that are run even if they are silent, and
153 decided to rebuild each target. Use
155 to disable all previous debugging flags.
157 \fB\-e\fR, \fB\-\-environment\-overrides\fR
158 Give variables taken from the environment precedence over variables
161 \fB\-E\fR \fIstring\fR, \fB\-\-eval\fR \fIstring\fR
162 Interpret \fIstring\fR using the \fBeval\fR function, before parsing any
165 \fB\-f\fR \fIfile\fR, \fB\-\-file\fR=\fIfile\fR, \fB\-\-makefile\fR=\fIFILE\fR
170 \fB\-i\fR, \fB\-\-ignore\-errors\fR
171 Ignore all errors in commands executed to remake files.
173 \fB\-I\fR \fIdir\fR, \fB\-\-include\-dir\fR=\fIdir\fR
174 Specifies a directory
176 to search for included makefiles.
179 options are used to specify several directories, the directories are
180 searched in the order specified.
181 Unlike the arguments to other flags of
183 directories given with
185 flags may come directly after the flag:
187 is allowed, as well as
190 This syntax is allowed for compatibility with the C
195 \fB\-j\fR [\fIjobs\fR], \fB\-\-jobs\fR[=\fIjobs\fR]
196 Specifies the number of
198 (commands) to run simultaneously.
199 If there is more than one
201 option, the last one is effective.
204 option is given without an argument,
206 will not limit the number of jobs that can run simultaneously.
208 \fB\--jobserver-style=\fR\fIstyle\fR
209 The style of jobserver to use. The
218 \fB\-k\fR, \fB\-\-keep\-going\fR
219 Continue as much as possible after an error.
220 While the target that failed, and those that depend on it, cannot
221 be remade, the other dependencies of these targets can be processed
224 \fB\-l\fR [\fIload\fR], \fB\-\-load\-average\fR[=\fIload\fR]
225 Specifies that no new jobs (commands) should be started if there are
226 others jobs running and the load average is at least
228 (a floating-point number).
229 With no argument, removes a previous load limit.
231 \fB\-L\fR, \fB\-\-check\-symlink\-times\fR
232 Use the latest mtime between symlinks and target.
234 \fB\-n\fR, \fB\-\-just\-print\fR, \fB\-\-dry\-run\fR, \fB\-\-recon\fR
235 Print the commands that would be executed, but do not execute them (except in
236 certain circumstances).
238 \fB\-o\fR \fIfile\fR, \fB\-\-old\-file\fR=\fIfile\fR, \fB\-\-assume\-old\fR=\fIfile\fR
239 Do not remake the file
241 even if it is older than its dependencies, and do not remake anything
242 on account of changes in
244 Essentially the file is treated as very old and its rules are ignored.
246 \fB\-O\fR[\fItype\fR], \fB\-\-output\-sync\fR[=\fItype\fR]
247 When running multiple jobs in parallel with \fB-j\fR, ensure the output of
248 each job is collected together rather than interspersed with output from
251 is not specified or is
253 the output from the entire recipe for each target is grouped together. If
257 the output from each command line within a recipe is grouped together.
262 output from an entire recursive make is grouped together. If
266 output synchronization is disabled.
268 \fB\-p\fR, \fB\-\-print\-data\-base\fR
269 Print the data base (rules and variable values) that results from
270 reading the makefiles; then execute as usual or as otherwise
272 This also prints the version information given by the
275 To print the data base without trying to remake any files, use
276 .IR "make \-p \-f/dev/null" .
278 \fB\-q\fR, \fB\-\-question\fR
280 Do not run any commands, or print anything; just return an exit status
281 that is zero if the specified targets are already up to date, nonzero
284 \fB\-r\fR, \fB\-\-no\-builtin\-rules\fR
285 Eliminate use of the built\-in implicit rules.
286 Also clear out the default list of suffixes for suffix rules.
288 \fB\-R\fR, \fB\-\-no\-builtin\-variables\fR
289 Don't define any built\-in variables.
291 \fB\-s\fR, \fB\-\-silent\fR, \fB\-\-quiet\fR
292 Silent operation; do not print the commands as they are executed.
295 Cancel the effect of the \fB\-s\fR option.
297 \fB\-S\fR, \fB\-\-no\-keep\-going\fR, \fB\-\-stop\fR
298 Cancel the effect of the
302 \fB\-t\fR, \fB\-\-touch\fR
303 Touch files (mark them up to date without really changing them)
304 instead of running their commands.
305 This is used to pretend that the commands were done, in order to fool
306 future invocations of
310 Information about the disposition of each target is printed (why the target is
311 being rebuilt and what commands are run to rebuild it).
313 \fB\-v\fR, \fB\-\-version\fR
314 Print the version of the
316 program plus a copyright, a list of authors and a notice that there
319 \fB\-w\fR, \fB\-\-print\-directory\fR
320 Print a message containing the working directory
321 before and after other processing.
322 This may be useful for tracking down errors from complicated nests of
327 .B \-\-no\-print\-directory
330 even if it was turned on implicitly.
332 .BI \-\-shuffle "[=MODE]"
333 Enable shuffling of goal and prerequisite ordering.
337 to disable shuffle mode,
339 to shuffle prerequisites in random order,
341 to consider prerequisites in reverse order, or an integer
349 is omitted the default is
352 \fB\-W\fR \fIfile\fR, \fB\-\-what\-if\fR=\fIfile\fR, \fB\-\-new\-file\fR=\fIfile\fR, \fB\-\-assume\-new\fR=\fIfile\fR
353 Pretend that the target
355 has just been modified.
358 flag, this shows you what would happen if you were to modify that file.
361 it is almost the same as running a
363 command on the given file before running
365 except that the modification time is changed only in the imagination of
368 .B \-\-warn\-undefined\-variables
369 Warn when an undefined variable is referenced.
373 exits with a status of zero if all makefiles were successfully parsed
374 and no targets that were built failed. A status of one will be returned
379 determines that a target needs to be rebuilt. A status of two will be
380 returned if any errors were encountered.
382 The full documentation for
384 is maintained as a Texinfo manual. If the
388 programs are properly installed at your site, the command
392 should give you access to the complete manual.
394 See the chapter ``Problems and Bugs'' in
395 .IR "The GNU Make Manual" .
397 This manual page contributed by Dennis Morse of Stanford University.
398 Further updates contributed by Mike Frysinger. It has been reworked by Roland
399 McGrath. Maintained by Paul Smith.
401 Copyright \(co 1992-1993, 1996-2022 Free Software Foundation, Inc.
405 GNU Make is free software; you can redistribute it and/or modify it under the
406 terms of the GNU General Public License as published by the Free Software
407 Foundation; either version 3 of the License, or (at your option) any later
410 GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
411 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
412 A PARTICULAR PURPOSE. See the GNU General Public License for more details.
414 You should have received a copy of the GNU General Public License along with
415 this program. If not, see
416 .IR https://www.gnu.org/licenses/ .