1 .TH MAKE 1 "03 March 2012" "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 the states
30 the commands for updating each file. In a program, typically the executable
31 file 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
51 to update one or more target
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
135 for all debugging output (same as using
140 for more verbose basic debugging,
142 for showing implicit rules,
144 for details on invocation of commands, and
146 for debugging while remaking makefiles.
148 \fB\-e\fR, \fB\-\-environment\-overrides\fR
149 Give variables taken from the environment precedence
150 over variables from makefiles.
152 \fB\-f\fR \fIfile\fR, \fB\-\-file\fR=\fIfile\fR, \fB\-\-makefile\fR=\fIFILE\fR
157 \fB\-i\fR, \fB\-\-ignore\-errors\fR
158 Ignore all errors in commands executed to remake files.
160 \fB\-I\fR \fIdir\fR, \fB\-\-include\-dir\fR=\fIdir\fR
161 Specifies a directory
163 to search for included makefiles.
166 options are used to specify several directories, the directories are
167 searched in the order specified.
168 Unlike the arguments to other flags of
170 directories given with
172 flags may come directly after the flag:
174 is allowed, as well as
177 This syntax is allowed for compatibility with the C
182 \fB\-j\fR [\fIjobs\fR], \fB\-\-jobs\fR[=\fIjobs\fR]
183 Specifies the number of
185 (commands) to run simultaneously.
186 If there is more than one
188 option, the last one is effective.
191 option is given without an argument,
193 will not limit the number of jobs that can run simultaneously.
195 \fB\-k\fR, \fB\-\-keep\-going\fR
196 Continue as much as possible after an error.
197 While the target that failed, and those that depend on it, cannot
198 be remade, the other dependencies of these targets can be processed
201 \fB\-l\fR [\fIload\fR], \fB\-\-load\-average\fR[=\fIload\fR]
202 Specifies that no new jobs (commands) should be started if there are
203 others jobs running and the load average is at least
205 (a floating-point number).
206 With no argument, removes a previous load limit.
208 \fB\-L\fR, \fB\-\-check\-symlink\-times\fR
209 Use the latest mtime between symlinks and target.
211 \fB\-n\fR, \fB\-\-just\-print\fR, \fB\-\-dry\-run\fR, \fB\-\-recon\fR
212 Print the commands that would be executed, but do not execute them (except in
213 certain circumstances).
215 \fB\-o\fR \fIfile\fR, \fB\-\-old\-file\fR=\fIfile\fR, \fB\-\-assume\-old\fR=\fIfile\fR
216 Do not remake the file
218 even if it is older than its dependencies, and do not remake anything
219 on account of changes in
221 Essentially the file is treated as very old and its rules are ignored.
223 \fB\-p\fR, \fB\-\-print\-data\-base\fR
224 Print the data base (rules and variable values) that results from
225 reading the makefiles; then execute as usual or as otherwise
227 This also prints the version information given by the
230 To print the data base without trying to remake any files, use
231 .IR "make \-p \-f/dev/null" .
233 \fB\-q\fR, \fB\-\-question\fR
235 Do not run any commands, or print anything; just return an exit status
236 that is zero if the specified targets are already up to date, nonzero
239 \fB\-r\fR, \fB\-\-no\-builtin\-rules\fR
240 Eliminate use of the built\-in implicit rules.
241 Also clear out the default list of suffixes for suffix rules.
243 \fB\-R\fR, \fB\-\-no\-builtin\-variables\fR
244 Don't define any built\-in variables.
246 \fB\-s\fR, \fB\-\-silent\fR, \fB\-\-quiet\fR
247 Silent operation; do not print the commands as they are executed.
249 \fB\-S\fR, \fB\-\-no\-keep\-going\fR, \fB\-\-stop\fR
250 Cancel the effect of the
253 This is never necessary except in a recursive
257 might be inherited from the top-level
259 via MAKEFLAGS or if you set
261 in MAKEFLAGS in your environment.
263 \fB\-t\fR, \fB\-\-touch\fR
264 Touch files (mark them up to date without really changing them)
265 instead of running their commands.
266 This is used to pretend that the commands were done, in order to fool
267 future invocations of
271 Print information about the commands invoked by
274 \fB\-v\fR, \fB\-\-version\fR
275 Print the version of the
277 program plus a copyright, a list of authors and a notice that there
280 \fB\-w\fR, \fB\-\-print\-directory\fR
281 Print a message containing the working directory
282 before and after other processing.
283 This may be useful for tracking down errors from complicated nests of
288 .B \-\-no\-print\-directory
291 even if it was turned on implicitly.
293 \fB\-W\fR \fIfile\fR, \fB\-\-what\-if\fR=\fIfile\fR, \fB\-\-new\-file\fR=\fIfile\fR, \fB\-\-assume\-new\fR=\fIfile\fR
294 Pretend that the target
296 has just been modified.
299 flag, this shows you what would happen if you were to modify that file.
302 it is almost the same as running a
304 command on the given file before running
306 except that the modification time is changed only in the imagination of
309 .B \-\-warn\-undefined\-variables
310 Warn when an undefined variable is referenced.
314 exits with a status of zero if all makefiles were successfully parsed
315 and no targets that were built failed. A status of one will be returned
320 determines that a target needs to be rebuilt. A status of two will be
321 returned if any errors were encountered.
323 The full documentation for
325 is maintained as a Texinfo manual. If the
329 programs are properly installed at your site, the command
333 should give you access to the complete manual.
335 See the chapter ``Problems and Bugs'' in
336 .IR "The GNU Make Manual" .
338 This manual page contributed by Dennis Morse of Stanford University.
339 Further updates contributed by Mike Frysinger. It has been reworked by Roland
340 McGrath. Maintained by Paul Smith.
342 Copyright \(co 1992-1993, 1996-2012 Free Software Foundation, Inc.
346 GNU Make is free software; you can redistribute it and/or modify it under the
347 terms of the GNU General Public License as published by the Free Software
348 Foundation; either version 3 of the License, or (at your option) any later
351 GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
352 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
353 A PARTICULAR PURPOSE. See the GNU General Public License for more details.
355 You should have received a copy of the GNU General Public License along with
356 this program. If not, see
357 .IR http://www.gnu.org/licenses/ .