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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, typi-cally typically
       cally  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  equiva-lent equivalent
            lent 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 a for all debugging output (same
            as using -d), b for basic debugging, v for more verbose basic debugging, i for showing  implicit
            rules, j for details on invocation of commands, and m for debugging while remaking makefiles.

       -e, --environment-overrides
            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.

       -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 any-thing anything
            thing 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
            Silent operation; do not print the commands as they are executed.

       -S, --no-keep-going, --stop
            Cancel the effect of the -k option.  This is never necessary except in a recursive make where -k
            might  be  inherited from the top-level make via MAKEFLAGS or if you set -k in MAKEFLAGS in your
            environment.

       -t, --touch
            Touch files (mark them up to date without really changing them) instead of  running  their  com-mands. commands.
            mands.  This is used to pretend that the commands were done, in order to fool future invocations
            of make.

       -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.

       -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 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 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  Gen-eral General
       eral  Public  License  as  published  by  the Free Software Foundation; either version 2, 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 GNU make; see  the  file
       COPYING.   If  not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
       MA 02110-1301, USA.



GNU                                            22 August 1989                                        MAKE(1)

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