make(1) User Commands make(1)
NAME
make - GNU Make utility to maintain groups of programs
SYNOPSIS
make [OPTION]... [TARGET]...
DESCRIPTION
The make utility will determine automatically which pieces of a large
program need to be recompiled, and issue the commands to recompile them.
The manual describes the GNU implementation of make, which was written by
Richard Stallman and Roland McGrath, and is currently maintained by Paul
Smith. Our examples show C programs, since they are very common, but you
can use make with any programming language whose compiler can be run with
a shell command. In fact, make is not limited to programs. You can use
it to describe any task where some files must be updated automatically
from others whenever the others change.
To prepare to use make, you must write a file called the makefile that
describes the relationships among files in your program, and provides
commands for updating each file. In a program, typically the executable
file is updated from object files, which are in turn made by compiling
source files.
Once a suitable makefile exists, each time you change some source files,
this simple shell command:
make
suffices to perform all necessary recompilations. The make program uses
the makefile description and the last-modification times of the files to
decide which of the files need to be updated. For each of those files,
it issues the commands recorded in the makefile.
make executes commands in the makefile to update one or more targets,
where target is typically a program. If no -f option is present, make
will look for the makefiles GNUmakefile, makefile, and Makefile, in that
order.
Normally you should call your makefile either makefile or Makefile. (We
recommend Makefile because it appears prominently near the beginning of a
directory listing, right near other important files such as README.) The
first name checked, GNUmakefile, is not recommended for most makefiles.
You should use this name if you have a makefile that is specific to GNU
Make, and will not be understood by other versions of make. If makefile
is '-', the standard input is read.
make updates a target if it depends on prerequisite files that have been
modified since the target was last modified, or if the target does not
exist.
OPTIONS
-b, -m
These options are ignored for compatibility with other versions of
make.
-B, --always-make
Unconditionally make all targets.
-C dir, --directory=dir
Change to directory dir before reading the makefiles or doing
anything else. If multiple -C options are specified, each is
interpreted relative to the previous one: -C / -C etc is equivalent
to -C /etc. This is typically used with recursive invocations of
make.
-d Print debugging information in addition to normal processing. The
debugging information says which files are being considered for
remaking, which file-times are being compared and with what results,
which files actually need to be remade, which implicit rules are
considered and which are applied---everything interesting about how
make decides what to do.
--debug[=FLAGS]
Print debugging information in addition to normal processing. If
the FLAGS are omitted, then the behavior is the same as if -d was
specified. FLAGS may be any or all of the following names, comma-
or space-separated. Only the first character is significant: the
rest may be omitted: all for all debugging output (same as using
-d), basic for basic debugging, verbose for more verbose basic
debugging, implicit for showing implicit rule search operations,
jobs for details on invocation of commands, makefile for debugging
while remaking makefiles, print shows all recipes that are run even
if they are silent, and why shows the reason make decided to rebuild
each target. Use none to disable all previous debugging flags.
-e, --environment-overrides
Give variables taken from the environment precedence over variables
from makefiles.
-E string, --eval string
Interpret string using the eval function, before parsing any
makefiles.
-f file, --file=file, --makefile=FILE
Use file as a makefile.
-i, --ignore-errors
Ignore all errors in commands executed to remake files.
-I dir, --include-dir=dir
Specifies a directory dir to search for included makefiles. If
several -I options are used to specify several directories, the
directories are searched in the order specified. Unlike the
arguments to other flags of make, directories given with -I flags
may come directly after the flag: -Idir is allowed, as well as -I
dir. This syntax is allowed for compatibility with the C
preprocessor's -I flag.
-j [jobs], --jobs[=jobs]
Specifies the number of jobs (commands) to run simultaneously. If
there is more than one -j option, the last one is effective. If the
-j option is given without an argument, make will not limit the
number of jobs that can run simultaneously.
--jobserver-style=style
The style of jobserver to use. The style may be one of fifo, pipe,
or sem (Windows only).
-k, --keep-going
Continue as much as possible after an error. While the target that
failed, and those that depend on it, cannot be remade, the other
dependencies of these targets can be processed all the same.
-l [load], --load-average[=load]
Specifies that no new jobs (commands) should be started if there are
others jobs running and the load average is at least load (a
floating-point number). With no argument, removes a previous load
limit.
-L, --check-symlink-times
Use the latest mtime between symlinks and target.
-n, --just-print, --dry-run, --recon
Print the commands that would be executed, but do not execute them
(except in certain circumstances).
-o file, --old-file=file, --assume-old=file
Do not remake the file file even if it is older than its
dependencies, and do not remake anything on account of changes in
file. Essentially the file is treated as very old and its rules are
ignored.
-O[type], --output-sync[=type]
When running multiple jobs in parallel with -j, ensure the output of
each job is collected together rather than interspersed with output
from other jobs. If type is not specified or is target the output
from the entire recipe for each target is grouped together. If type
is line the output from each command line within a recipe is grouped
together. If type is recurse output from an entire recursive make
is grouped together. If type is none output synchronization is
disabled.
-p, --print-data-base
Print the data base (rules and variable values) that results from
reading the makefiles; then execute as usual or as otherwise
specified. This also prints the version information given by the -v
switch (see below). To print the data base without trying to remake
any files, use make -p -f/dev/null.
-q, --question
``Question mode''. Do not run any commands, or print anything; just
return an exit status that is zero if the specified targets are
already up to date, nonzero otherwise.
-r, --no-builtin-rules
Eliminate use of the built-in implicit rules. Also clear out the
default list of suffixes for suffix rules.
-R, --no-builtin-variables
Don't define any built-in variables.
-s, --silent, --quiet
Silent operation; do not print the commands as they are executed.
--no-silent
Cancel the effect of the -s option.
-S, --no-keep-going, --stop
Cancel the effect of the -k option.
-t, --touch
Touch files (mark them up to date without really changing them)
instead of running their commands. This is used to pretend that the
commands were done, in order to fool future invocations of make.
--trace
Information about the disposition of each target is printed (why the
target is being rebuilt and what commands are run to rebuild it).
-v, --version
Print the version of the make program plus a copyright, a list of
authors and a notice that there is no warranty.
-w, --print-directory
Print a message containing the working directory before and after
other processing. This may be useful for tracking down errors from
complicated nests of recursive make commands.
--no-print-directory
Turn off -w, even if it was turned on implicitly.
--shuffle[=MODE]
Enable shuffling of goal and prerequisite ordering. MODE is one of
none to disable shuffle mode, random to shuffle prerequisites in
random order, reverse to consider prerequisites in reverse order, or
an integer <seed> which enables random mode with a specific seed
value. If MODE is omitted the default is random.
-W file, --what-if=file, --new-file=file, --assume-new=file
Pretend that the target file has just been modified. When used with
the -n flag, this shows you what would happen if you were to modify
that file. Without -n, it is almost the same as running a touch
command on the given file before running make, except that the
modification time is changed only in the imagination of make.
--warn-undefined-variables
Warn when an undefined variable is referenced.
EXIT STATUS
GNU Make exits with a status of zero if all makefiles were successfully
parsed and no targets that were built failed. A status of one will be
returned if the -q flag was used and make determines that a target needs
to be rebuilt. A status of two will be returned if any errors were
encountered.
SEE ALSO
The full documentation for make is maintained as a Texinfo manual. If
the info and make programs are properly installed at your site, the
command
info make
should give you access to the complete manual.
BUGS
See the chapter ``Problems and Bugs'' in The GNU Make Manual.
AUTHOR
This manual page contributed by Dennis Morse of Stanford University.
Further updates contributed by Mike Frysinger. It has been reworked by
Roland McGrath. Maintained by Paul Smith.
COPYRIGHT
Copyright © 1992-1993, 1996-2023 Free Software Foundation, Inc. This
file is part of GNU Make.
GNU Make 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 3 of the License, or (at your option)
any later version.
GNU Make 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 this program. If not, see https://www.gnu.org/licenses/.
GNU 26 May 2023 make(1)
gmake 4.4.1 - Generated Thu Mar 23 18:58:39 CDT 2023