假設有如下程序：

#include "hellomake.h"

int main() {
  // call a function in another file
  myPrintHelloMake();

  return(0);
}

#include <stdio.h>
#include "hellomake.h"

void myPrintHelloMake(void) {

  printf("Hello makefiles!\n");

  return;
}

使用命令行編譯

gcc -o hellomake hellomake.c hellofunc.c

缺點：

1. 如果有更多的文件，gcc命令復雜

2. 如果只改動某個文件，所有文件都需要重新編譯

Makefile 版本1

hellomake: hellomake.c hellofunc.c
     gcc -o hellomake hellomake.c hellofunc.c 

Makefile 文件中包含一組用編譯應用程序的規則，make 看到的第一項規則叫默認規則。

規則由三部分組成： target, prerequiste, command.

target: prereq1 prereq2

　　commands

缺點：

* 所有代碼文件都在同一目錄中

Makefile 版本2

CC=gcc
CFLAGS=-I.

hellomake: hellomake.o hellofunc.o
     $(CC) -o hellomake hellomake.o hellofunc.o -I.

Makefile 版本3

CC=gcc
CFLAGS=-I.
DEPS = hellomake.h

%.o: %.c $(DEPS)
    $(CC) -c -o $@ $< $(CFLAGS)

hellomake: hellomake.o hellofunc.o 
    gcc -o hellomake hellomake.o hellofunc.o -I.

Makefile 版本5

CC=gcc
CFLAGS=-I.
DEPS = hellomake.h
OBJ = hellomake.o hellofunc.o 

%.o: %.c $(DEPS)
    $(CC) -c -o $@ $< $(CFLAGS)

hellomake: $(OBJ)
    gcc -o $@ $^ $(CFLAGS)

Makefile 版本6

IDIR =../include
CC=gcc
CFLAGS=-I$(IDIR)

ODIR=obj
LDIR =../lib

LIBS=-lm

_DEPS = hellomake.h
DEPS = $(patsubst %,$(IDIR)/%,$(_DEPS))

_OBJ = hellomake.o hellofunc.o 
OBJ = $(patsubst %,$(ODIR)/%,$(_OBJ))


$(ODIR)/%.o: %.c $(DEPS)
    $(CC) -c -o $@ $< $(CFLAGS)

hellomake: $(OBJ)
    gcc -o $@ $^ $(CFLAGS) $(LIBS)

.PHONY: clean
clean:
    rm -f $(ODIR)/*.o *~ core $(INCDIR)/*~ 

使用工作區

all

install

clean

disclean

TAGS

info

check

在BSD與Linux平臺通用的makefile

編譯 make

Debug make DEBUG=1

BSD gmake BSD=1

# Makefile for utelnetd
# 
# Configure this with the following environment variables:
#

# where to install
INSTDIR        := /usr/local/bin/

# GNU target string 
CROSS        :=

# where to find login program
ifneq ("", "$(BSD)")
LOGIN        := /usr/bin/login
else
LOGIN        := /bin/login
endif

ifneq ("", "$(BSD)")
CORE        := utelnetd.core
else
CORE        := core
endif

# nothing to configure below this line... ---8<---8<---8<---

PROGS     = utelnetd

INSTMODE  = 0755
INSTOWNER = root
INSTGROUP = root

OBJS      = utelnetd.o

CC        = $(CROSS)gcc
INSTALL   = install

CFLAGS     += -I. -pipe -DSHELLPATH=\"$(LOGIN)\" -Wall

ifneq ("","$(DEBUG)")
CFLAGS   += -DDEBUG -g -Os
STRIP      = \#
else
CFLAGS     += -fomit-frame-pointer
STRIP      = $(CROSS)strip 
endif

ifeq ("1", "$(BSD)")
CFLAGS   += -DBSD
endif


all: $(PROGS)

$(PROGS): $(OBJS)
    $(CC) $(LDFLAGS) $^ $(LDLIBS) -o $@
    $(STRIP) --remove-section=.comment --remove-section=.note $@

.PHONY: install
install: $(PROGS)
    $(INSTALL) -d $(INSTDIR)
    $(INSTALL) -m $(INSTMODE) -o $(INSTOWNER) -g $(INSTGROUP) $(PROGS) $(INSTDIR)

.PHONY: clean
clean:
    rm -f $(PROGS) *.o $(CORE)

GNU make 官方文檔 https://www.gnu.org/software/make/manual/make.html

GNU Make 快速教程