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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,  `makefile'
       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  con-
       struction  commands.   For example, a `.c' file may be inferred as pre-
       requisite 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  accu-
       mulate;  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  termi-
       nate  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 cur-
              rent 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 execut-
              ing 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  over-
       come the difficulty.
       Commands  that  are  directly executed by the shell, notably cd(1), are
       ineffectual across newlines in make.



                                                                       MAKE(1)