make - phpMan

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 exam-
ples 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 sim-
ple shell command:

make

suffices to perform all necessary recompilations. The make program uses the make-
file 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, GNUmake-
file, 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 ver-
sions 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 pre-
vious 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---every-
thing 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 make-
files.

+-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, directo-
ries 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 pre-
processor'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 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
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 MAKE-
FLAGS 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 pro-
cessing. 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. With-
out -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.