MAKE HELP

File:		make.help
Author:		course (send problems to walton@deas)
Version:	3

Purpose: "make" permits you to program UNIX "buttons"
similar in function to the buttons in a popdown menu.
You give these buttons names, called targets, and type
"make target" instead of clicking on a button.  These
targets sometimes also correspond to output files made
by executing some UNIX commands, and in this case
"clicking" on the target means to execute the commands
that make the file.  To this is added the twist of
suppressing execution if the file is newer than the
files it is made from.

Makefile	Name of file containing make commands.
		Each directory can have its own
		Makefile.

make <target>	UNIX command to make the <target>
		according to instructions in current
		directory's Makefile.

The "make" Commands in Makefile:

    Instructions for making <target> given <source1>,
    <source2>, etc.:

    <target>:	<source1> <source2> ...
	    <command1>
	    <command2>
	    . . .

	First make the <source>s, if there are any
	instructions for doing so.  Then, if the
	<target> is older than any source, or the
	<target> does not exist, execute the commands in
	order to make the <target>.

    <macroname> = <value>   Define (parameterless)
			    macro.
    $(<macroname>)	    Replaced by macro
			    definition.

    $@	    Replaced by current <target> name.
    $*	    Replaced by current <target> name with
	    extension removed.  (xx.c becomes xx)
    $$	    Denotes a single $.
    #	    If first character of line, identifies
	    the line as a comment line.


Notes:

    Commands are executed by the Bourne shell, sh(1),
    and not the C-shell, csh(1).  E.g. ~ is
    unrecognized.

    Commands on separate lines are executed by separate
    invocations of sh(1) and cannot share shell
    variables.

    The UNIX command "make" with no arguments makes the
    first target in "Makefile".

    The precise format of the instructions for making
    a <target> above is:

    <target>:<tab><source1> <source2> ...
    <tab><command1>
    <tab><command2>
    .....

    That is, the colon MUST be followed by a TAB, and
    the command lines MUST begin with a TAB.

    To continue a command or macro definition or list of
    sources onto the next line, end the current line
    with a backslash (\).

    HP-UX make does NOT correctly identify the time of
    symbolically linked files (see man ln, the -s
    option, for a definition of symbolic linking).