MAKE(1L)                      LOCAL USER COMMANDS                     MAKE(1L)

       make - GNU make utility to maintain groups of programs

       make [ -f makefile ] [ option ] ...  target ...

       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
       which is made from the Texinfo source file make.texinfo.

       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.  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:


       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.


       -m   These options are ignored for compatibility with other versions of

       -C 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.

       -e   Give variables taken from the environment precedence over
            variables from makefiles.

       -f file
            Use file as a makefile.

       -i   Ignore all errors in commands executed to remake files.

       -I 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
            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   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
            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

       -n   Print the commands that would be executed, but do not execute

       -o 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 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 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   Eliminate use of the built-in implicit rules.  Also clear out the
            default list of suffixes for suffix rules.

       -s   Silent operation; do not print the commands as they are executed.

       -S   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

       -t   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

       -v   Print the version of the make program plus a copyright, a list of
            authors and a notice that there is no warranty.

       -w   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.

       -W 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

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

       This manual page contributed by Dennis Morse of Stanford University.
       It has been reworked by Roland McGrath.

GNU                             22 August 1989                        MAKE(1L)