相信每個學習Linux的人都知道Makefile，這是一個很有用的東西，但是編寫它是比較複雜，今天介紹一個它的自動生成工具，autotools的使用。很多GNULinux的的軟體都是用它生成Makefile的，包括我們非常熟悉的Linux核心原始碼。

  1、準備:

  需要工具

  autoscan

  aclocal

  autoheader 

  automake

  autoconf

  auto make 

  在終端敲入命令，哪個沒有安裝哪個，一般是第一個autoscan沒有，其它的我用的Ubuntu10.04下全部都有

  2、測試程式編寫：
     建立目錄：mkdir include src

     編寫程式：include/str.h

#include <stdio.h>
int str(char *string);

    編寫程式：src/str.c

#include "str.h"
//print string
int str(char *string){
        printf("\n----PRINT STRING----\n\"%s\"\n",string);
        return 0;
}

//interface of this program
int main(int argc , char **argv){
        char str_read[1024];
        printf("Please INPUT something end by [ENTER]\n");
        scanf("%s",str_read);
        return str(str_read );
}

     
 

  3、生成configure.ac

    configure.ac是automake的輸入檔案，所以必須先生成該檔案。
    執行命令：

[[email protected] str]# ls
include  src
[[email protected] str]# autoscan
autom4te: configure.ac: no such file or directory
autoscan: /usr/bin/autom4te failed with exit status: 1
[[email protected] str]# ls
autoscan.log  configure.scan  include  src
[
 
[email protected] str]# cp configure.scan configure.ac 

    修改 configure.ac 

#                                               -*- Autoconf -*-
# Process this file with autoconf to produce a configure script.

AC_PREREQ(2.59)
AC_INIT(FULL-PACKAGE-NAME, VERSION, BUG-REPORT-ADDRESS)
AC_CONFIG_SRCDIR([include/str.h])
AC_CONFIG_HEADER([config.h])

# Checks for programs.
AC_PROG_CC

# Checks for libraries.

# Checks for header files.

# Checks for typedefs, structures, and compiler characteristics.

# Checks for library functions.
AC_OUTPUT

修改

AC_INIT(FULL-PACKAGE-NAME, VERSION, BUG-REPORT-ADDRESS)

改為：

AC_INIT(str,0.0.1, [[email protected]])

其中：FULL-PACKAGE-NAME 為程式名稱，VERSION為當前版本， BUG-REPORT-ADDRESS為bug彙報地址

然後新增兩句話：

    AM_INIT_AUTOMAKE
    AC_CONFIG_FILES([Makefile])

結果如下：（兩句話不是在一起的）

#                                               -*- Autoconf -*-
# Process this file with autoconf to produce a configure script.

AC_PREREQ(2.59)
#AC_INIT(FULL-PACKAGE-NAME, VERSION, BUG-REPORT-ADDRESS)
AC_INIT(str, 0.0.1, [[email protected]])
AM_INIT_AUTOMAKE
AC_CONFIG_SRCDIR([include/str.h])
AC_CONFIG_HEADER([config.h])

# Checks for programs.
AC_PROG_CC

# Checks for libraries.

# Checks for header files.

# Checks for typedefs, structures, and compiler characteristics.

# Checks for library functions.
AC_CONFIG_FILES([Makefile])
AC_OUTPUT

4、執行aclocal

[[email protected] str]# aclocal
/usr/share/aclocal/libfame.m4:6: warning: underquoted definition of AM_PATH_LIBFAME
  run info '(automake)Extending aclocal'
  or see http://sources.redhat.com/automake/automake.html#Extending-aclocal

5、製作Makefile.am

[[email protected] str]# vi Makefile.am
#Makefile.am
bin_PROGRAMS    = str
str_SOURCES     = include/str.h src/str.c
str_CPPFLAGS    = -I include/

automake 這個命令需要用到這個配置檔案。各個選項意思比較直觀，不多說。

6、autoheader

[[email protected] str]# autoheader

7、automake必須檔案：

    *  install-sh
    * missing
    * INSTALL
    * NEWS
    * README
    * AUTHORS
    * ChangeLog
    * COPYING
    * depcomp 

其中，以下檔案在執行automake -a的時候會自動生成

    * install-sh
    * missing
    * INSTALL
    * COPYING
    * depcomp 

所以，接下來手動生成剩下的檔案

[[email protected] str]# touch NEWS README AUTHORS ChangeLog

8、執行automake -a

[[email protected] str]# automake -a
configure.ac: installing `./install-sh'
configure.ac: installing `./missing'
Makefile.am: installing `./INSTALL'
Makefile.am: installing `./COPYING'
Makefile.am: installing `./compile'
Makefile.am: installing `./depcomp'

9、autoconf

[[email protected] str]# autoconf
[[email protected] str]# ls
aclocal.m4      autoscan.log  config.h.in   configure.scan  include     Makefile.am  NEWS
AUTHORS         ChangeLog     configure     COPYING         INSTALL     Makefile.in  README
autom4te.cache  compile       configure.ac  depcomp         install-sh  missing      src

10、執行測試：
      執行./configure

[[email protected] str]# ./configure --prefix=/u
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for gawk... gawk
checking whether make sets $(MAKE)... yes
checking for gcc... gcc
checking for C compiler default output file name... a.out
checking whether the C compiler works... yes
checking whether we are cross compiling... no
checking for suffix of executables...
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ANSI C... none needed
checking for style of include used by make... GNU
checking dependency style of gcc... gcc3
configure: creating ./config.status
config.status: creating Makefile
config.status: creating config.h
config.status: config.h is unchanged
config.status: executing depfiles commands

執行 make

[[email protected] str]# make
make  all-am
make[1]: Entering directory `/data/devel/c/str'
if gcc -DHAVE_CONFIG_H -I. -I. -I.  -I include/   -g -O2 -MT str-str.o -MD -MP -MF ".deps/str-str.Tpo" -c -o str-str.o `test -f 'src/str.c' || echo './'`src/str.c; \
then mv -f ".deps/str-str.Tpo" ".deps/str-str.Po"; else rm -f ".deps/str-str.Tpo"; exit 1; fi
gcc  -g -O2   -o str  str-str.o
make[1]: Leaving directory `/data/devel/c/str'

此時已經生成了 str（可執行檔名字在前面設定Makefile.am的引數時候去頂）這個，可以通過./str直接看到執行結果

[[email protected] str]# ./str
Please INPUT something end by [ENTER]
abcksdhfklsdklfdjlkfd

----PRINT STRING----
"abcksdhfklsdklfdjlkfd"

不過這裡我們都做一步，把它安裝到系統裡面，這樣我們只要在終端輸入str就可以執行程式了。

 執行 make install：

[[email protected] str]# make install
make[1]: Entering directory `/data/devel/c/str'
test -z "/u/bin" || mkdir -p -- "/u/bin"
  /usr/bin/install -c 'str' '/u/bin/str'
make[1]: Nothing to be done for `install-data-am'.
make[1]: Leaving directory `/data/devel/c/str'     

接下來你可以make clean 清除安裝的那些.o 檔案了。

這樣生成了一個自動的Makefile。