MAKE(1) 						      General Commands Manual							   MAKE(1)

NAME

       make - maintain program groups

SYNOPSIS

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

DESCRIPTION

       Make  executes  commands  in makefile to update one or more target names.  Name is typically a program.	If no -f option is present, `make-
       file' and `Makefile' are tried in order.  If makefile is `-', the standard input is taken.  More than one -f option may appear

       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.

       Makefile contains a sequence of entries that specify dependencies.  The first line of an entry is a blank-separated list of targets, then a
       colon, then a list of prerequisite files.  Text following a semicolon, and all following lines that begin with a tab, are shell commands to
       be executed to update the target.

       Sharp and newline surround comments.

       The  following  makefile says that `pgm' depends on two files `a.o' and `b.o', and that they in turn depend on `.c' files and a common file
       `incl'.

		     pgm: a.o b.o
		     cc a.o b.o -lm -o pgm
	      a.o: incl a.c
		     cc -c a.c
	      b.o: incl b.c
		     cc -c b.c

       Makefile entries of the form

	      string1 = string2

       are macro definitions.  Subsequent appearances of $(string1) are replaced by string2.  If string1 is a single  character,  the  parentheses
       are optional.

       Make infers prerequisites for files for which makefile gives no construction commands.  For example, a `.c' file may be inferred as prereq-
       uisite for a `.o' file and be compiled to produce the `.o' file.  Thus the preceding example can be done more briefly:

		     pgm: a.o b.o
		     cc a.o b.o -lm -o pgm
	      a.o b.o: incl

       Prerequisites are inferred according to selected suffixes listed as the `prerequisites' for the special name  `.SUFFIXES';  multiple  lists
       accumulate;  an	empty  list  clears  what  came before.  Order is significant; the first possible name for which both a file and a rule as
       described in the next paragraph exist is inferred.  The default list is

	      .SUFFIXES: .out .o .c .e .r .f .y .l .s

       The rule to create a file with suffix s2 that depends on a similarly named file with suffix s1 is specified as an entry	for  the  `target'
       s1s2.   In such an entry, the special macro $* stands for the target name with suffix deleted, $@ for the full target name, $< for the com-
       plete list of prerequisites, and $? for the list of prerequisites that are out of date.	For example, a	rule  for  making  optimized  `.o'
       files from `.c' files is

	      .c.o: ; cc -c -O -o $@ $*.c

       Certain	macros	are  used  by the default inference rules to communicate optional arguments to any resulting compilations.  In particular,
       `CFLAGS' is used for cc and f77(1) options, `LFLAGS' and `YFLAGS' for lex and yacc(1) options.

       Command lines are executed one at a time, each by its own shell.  A line is printed when it is executed unless the special target `.SILENT'
       is in makefile, or the first character of the command is `@'.

       Commands  returning nonzero status (see intro(1)) cause make to terminate unless the special target `.IGNORE' is in makefile or the command
       begins with <tab><hyphen>.

       Interrupt and quit cause the target to be deleted unless the target depends on the special name `.PRECIOUS'.

       Other options:

       -i     Equivalent to the special entry `.IGNORE:'.

       -k     When a command returns nonzero status, abandon work on the current entry, but continue on branches that do not depend on the current
	      entry.

       -n     Trace and print, but do not execute the commands needed to update the targets.

       -t     Touch, i.e. update the modified date of targets, without executing any commands.

       -r     Equivalent to an initial special entry `.SUFFIXES:' with no list.

       -s     Equivalent to the special entry `.SILENT:'.

FILES

       makefile, Makefile

SEE ALSO

       sh(1), touch(1)
       S. I. Feldman Make - A Program for Maintaining Computer Programs

BUGS

       Some commands return nonzero status inappropriately.  Use -i to overcome the difficulty.
       Commands that are directly executed by the shell, notably cd(1), are ineffectual across newlines in make.

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