linux 在shell脚本中获取该脚本的所在绝对路径2

脚本名：a.sh

位置：/tmp/whuang/study/java

脚本内容：

this_dir=`pwd`
file_name=`basename $0`
dirname $0|grep "^/" >/dev/null
if [ $? -eq 0 ];then
    this_dir=`dirname $0`
else
        dirname $0|grep "^\.\." >/dev/null
        retval=$?
        if [ $retval -eq 0 ];then
               this_dir=`dirname $0|sed "s#^#$this_dir/#"`
        else
                        dirname $0|grep "^\./" >/dev/null
                        retval=$?
                        if [ $retval -eq 0 ];then
                                this_dir=`dirname $0|sed "s#^\.\(/.*\)#$this_dir\1#"`
                        else
                                this_dir=`dirname $0|sed "s#^#$this_dir/#"`
                        fi
                fi
fi
echo $this_dir

?----------------------------------------------

功能：获取脚本的绝对路径。

测试：

?

[root@ppc40 java]# pwd

/tmp/whuang/study/java

[root@ppc40 java]# sh a.sh

/tmp/whuang/study/java

[root@ppc40 java]# cd ..

[root@ppc40 study]# sh java/a.sh

/tmp/whuang/study/java

[root@ppc40 study]# sh ./java/a.sh

/tmp/whuang/study/java

?

[root@ppc40 study]# sh ../study/java/a.sh

/tmp/whuang/study/../study/java