NAME make – utility for building and maintaining groups of programs. DESCRIPTION make The purpose of how to make oyster stew with canned oysters make utility is to determine automatically which pieces of a large program need to be recompiled, and issue the commands to recompile them. 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. These options are ignored for compatibility with other versions of make. Change to directory dir before reading the makefiles or doing anything else. This is typically used with recursive invocations of make. 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. If the FLAGS are omitted, then the behavior is the same as if -d was specified. Give variables taken from the environment precedence over variables from makefiles. 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.

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. 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. With no argument, removes a previous load limit. Use the latest mtime between symlinks and target.

Print the commands that would be executed, but do not execute them. 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. This also prints the version information given by the -v switch. Eliminate use of the built-in implicit rules. Also clear out the default list of suffixes for suffix rules.

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. This is used to pretend that the commands were done, in order to fool future invocations of make. Print the version of the make program plus a copyright, a list of authors and a notice that there is no warranty.

Print a message containing the working directory before and after other processing. Turn off -w, even if it was turned on implicitly. 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 when an undefined variable is referenced.