make


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  oth-
       ers 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 exe-
       cutable 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 begin-
       ning 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.
            preted  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 interest-
            ing 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  com-
            mands, and m for debugging while remaking makefiles.

       -e, --environment-overrides
            Give  variables  taken  from the environment precedence over vari-
            ables 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 argu-
            ments  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.
            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 spec-
            ified.  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 commands.  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.

       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 General 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  Soft-
       ware  Foundation,  Inc.,  51  Franklin  St,  Fifth  Floor,  Boston,  MA
       02110-1301, USA.



GNU                             22 August 1989                         MAKE(1)
Man Pages Copyright Respective Owners. Site Copyright (C) 1994 - 2014 Hurricane Electric. All Rights Reserved.