Makefile自动生成工具-----autotools的使用（详细）
相信每个学习Linux的人都知道Makefile，这是一个很有用的东西，但是编写它是比较复杂，今天介绍一个它的自动生成工具，autotools的使用。很多GNULinux的的软件都是用它生成Makefile的，包括我们非常熟悉的Linux内核源代码。
需要工具
autoscan
aclocal
autoheader
automake
autoconf
auto make
在终端敲入命令，哪个没有安装哪个，一般是第一个autoscan没有，其它的我用的Ubuntu10.04下全部都有
建立目录：mkdir include src
编写程序：include/str.h
#include
int str(char *string); 编写程序：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的输入文件，所以必须先生成该文件。
执行命令：
[root@localhost str]# ls
include src
[root@localhost str]# autoscan
autom4te: configure.ac: no such file or directory
autoscan: /usr/bin/autom4te failed with exit status: 1
[root@localhost str]# ls
autoscan.log configure.scan include src
[root@localhost 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)改为：
AC_INIT(str,0.0.1, [[email protected]])其中：FULL-PACKAGE-NAME 为程序名称，VERSION为当前版本， BUG-REPORT-ADDRESS为bug汇报地址
然后添加两句话：
AM_INIT_AUTOMAKE
AC_CONFIG_FILES([Makefile])
结果如下：（两句话不是在一起的）
# -*- 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_OUTPUT4、执行aclocal
[root@localhost 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-aclocal5、制作Makefile.am
[root@localhost str]# vi Makefile.am
#Makefile.am
bin_PROGRAMS = str
str_SOURCES = include/str.h src/str.c
str_CPPFLAGS = -I include/automake 这个命令需要用到这个配置文件。各个选项意思比较直观，不多说。
6、autoheader
[root@localhost str]# autoheader7、automake必须文件：
* install-sh
* missing
* INSTALL
* NEWS
* README
* AUTHORS
* ChangeLog
* COPYING
* depcomp 其中，以下文件在执行automake -a的时候会自动生成
* install-sh
* missing
* INSTALL
* COPYING
* depcomp 所以，接下来手动生成剩下的文件
[root@localhost str]# touch NEWS README AUTHORS ChangeLog8、执行automake -a
[root@localhost 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
[root@localhost str]# autoconf
[root@localhost 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 src10、执行测试：
执行./configure
[root@localhost 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执行 make
[root@localhost 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'此时已经生成了 str（可执行文件名字在前面设置Makefile.am的参数时候去顶）这个，可以通过./str直接看到运行结果
[root@localhost str]# ./str
Please INPUT something end by [ENTER]
abcksdhfklsdklfdjlkfd
----PRINT STRING----
"abcksdhfklsdklfdjlkfd"不过这里我们都做一步，把它安装到系统里面，这样我们只要在终端输入str就可以运行程序了。
执行 make install：
[root@localhost 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' 接下来你可以make clean 清除安装的那些.o 文件了。
这样生成了一个自动的Makefile。