|
|
|
Home > Help Files > Unix > Make
UNIX: make
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 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.
For more information, run "man make" at the prompt.
|
|
© |