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MAKE(1)                                          LOCAL USER COMMANDS                                          MAKE(1)



NAME
       make - GNU make utility to maintain groups of programs

SYNOPSIS
       make [ -f makefile ] [ options ] ... [ targets ] ...

WARNING
       This  man  page  is an extract of the documentation of GNU make.  It is updated only occasionally, because the
       GNU project does not use nroff.  For complete, current documentation, refer to the Info file  make.info  which
       is made from the Texinfo source file make.texi.

DESCRIPTION
       The  purpose  of  the  make  utility  is to 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 most 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 the states the 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 data base 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 data base.

       make executes commands in the makefile to update one or more target names, where name 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.

            Give variables taken from the environment precedence over variables from 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.

       -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.

       -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

            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.

       -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  com‐
            mand  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 GNU Make Manual

BUGS
       See the chapter `Problems and Bugs' in The GNU Make Manual.

AUTHOR
       This manual page contributed by Dennis Morse of Stanford University.  It has been reworked by Roland  McGrath.
       Further updates contributed by Mike Frysinger.

COPYRIGHT
       Copyright (C) 1992, 1993, 1996, 1999, 2007 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
       http://www.gnu.org/licenses/.



GNU                                                 22 August 1989                                            MAKE(1)