Make

• One of the basic Unix programming tools is "make"

• Make allows you to manage large programming projects
• Allows you to break things into smaller chunks so compiles can be smaller

• Though make is designed for programming tasks, it can be used for any task that requires something to be done when files change

• To make make do its thing, you need to give it some instructions
• The instructions are in a file called a makefile

• The file can have any name, but if it is "Makefile" or "makefile," you don't need to specify a name on the command line
• We'll call it a "makefile," no matter what it's called

• Format

• The Makefile contains 4 types of lines, plus comments

• Comments begin with "#"
• Target lines define target files and their dependencies
• Shell command lines define how to create targets
• Macro lines define macros to save typing in the makefile
• Make directive lines

• Target lines

• Format: target: dependencies
• If anything in the dependency list is newer than the target, the target will be regenerated

• "Newer" is simply based on the modification time of the file

• Shell command lines

• Immediately follow a target line, and define how to generate the target
• Any shell command is valid
• Must be preceeded by a tab character

• Macros

• Allow defining a chunk of text by name
• Format: name = value
• Referenced by $(name)
• Macros may be defined in the makefile or on the command line

• Other makefile features

• By default, make knows that you can make a ".o" file from a ".c" file of the same name with

            %  cc -c file.c

 so you don't need to specify this command if that's all there is to it

• Make pre-defines some macros

• CC Defines the command name of the C compiler. The default is "cc".
• CFLAGS Defines flags that should always be added to the compiler (for example "-g" to enable debugging)
• $@ Defines the full name of the current target.
• $? Defines the list of dependency files for the current target that are out of date
• $< Defines the name of the current dependency

# Makefile for ephem, v 4.28

CLDFLAGS =

CFLAGS = $(CLDFLAGS) -O

LDFLAGS = $(CLDFLAGS)

LIBS = -ltermcap -lm

OBJS=   aa_hadec.o altj.o altmenus.o anomaly.o cal_mjd.o circum.o comet.o compiler.o constel.o eq_ecl.o flog.o formats.o io.o listing.o main.o mainmenu.o moon.o moonnf.o nutation.o objx.o obliq.o parallax.o pelement.o plans.o plot.o popup.o precess.o reduce.o refract.o riset.o riset_c.o sel_fld.o sex_dec.o srch.o sun.o time.o utc_gst.o version.o watch.o

ephem:  $(OBJS)

        cc $(LDFLAGS) -o $@ $(EPHEM) $(LIBS)

aa_hadec.o:    astro.h

altj.o:        astro.h circum.h screen.h

altmenus.o:    astro.h circum.h screen.h

anomaly.o:     astro.h

cal_mjd.o:     astro.h

circum.o:      astro.h circum.h screen.h

comet.o:       astro.h

compiler.o:    screen.h

constel.o:     astro.h circum.h screen.h

eq_ecl.o:      astro.h

flog.o:        screen.h

formats.o:     astro.h screen.h

io.o:          screen.h

listing.o:     screen.h

main.o:        astro.h circum.h screen.h

mainmenu.o:    astro.h circum.h screen.h

moon.o:        astro.h

moonnf.o:      astro.h

nutation.o:    astro.h

objx.o:        astro.h circum.h screen.h

obliq.o:       astro.h

parallax.o:    astro.h

pelement.o:    astro.h

plans.o:       astro.h

plot.o:        screen.h

popup.o:       screen.h

precess.o:     astro.h

reduce.o:      astro.h

refract.o:     astro.h

riset.o:       astro.h

riset_c.o:     astro.h circum.h screen.h

sel_fld.o:     screen.h

srch.o:        screen.h

sun.o:         astro.h

time.o:        astro.h circum.h

utc_gst.o:     astro.h

version.o:     screen.h

watch.o:       astro.h circum.h screen.h