Contents
3.37. example(字符串处理)¶
3.37.1. 变量替换的六种形式¶
3.37.2. 字符串处理¶
计算字符串长度
方法一
${#string}
方法二
string有空格，则必须加双引号
expr length "$string"
获取子串在字符串中的索引位置
expr index $string $substring
计算子串长度
expr match $string substr
eg
[root@VM_0_9_centos shell_learn]# var1="quickstart is a app"
[root@VM_0_9_centos shell_learn]# len=`expr match "$var1" quic`
[root@VM_0_9_centos shell_learn]# echo $len
4
[root@VM_0_9_centos shell_learn]# len=`expr match "$var1" app`
[root@VM_0_9_centos shell_learn]# echo $len
0
[root@VM_0_9_centos shell_learn]# len=`expr match "$var1" quic.*`
[root@VM_0_9_centos shell_learn]# echo $len
19
[root@VM_0_9_centos shell_learn]#
3.37.3. 抽取子串¶
3.37.4. 字符串处理完整脚本 example.sh¶
#!/bin/bash
string="Bigdata process framework is Hadoop,Hadoop is an open source project"
function print_tips
{
echo "******************************"
echo "(1)打印string长度"
echo "(2)删除字符串中所有的Hadoop"
echo "(3)替换第一个Hadoop为Mapreduce"
echo "(4)替换全部Hadoop为Mapreduce"
echo "*******************************"
}
function len_of_string
{
echo "${#string}"
}
function del_hadoop
{
echo "${string//Hadoop/}"
}
function rep_hadoop_mapreduce_first
{
echo "${string/Hadoop/Mapreduce}"
}
function rep_hadoop_mapreduce_all
{
echo "${string//Hadoop/Mapreduce}"
}
while true
do
echo "[string=$string]"
echo
print_tips
read -p "Pls input your choice(1|2|3|4|q|Q): " choice
case $choice in
1)
len_of_string
;;
2)
del_hadoop
;;
3)
rep_hadoop_mapreduce_first
;;
4)
rep_hadoop_mapreduce_all
;;
q|Q)
exit
;;
*)
echo "Error,input only in {1|2|3|4|q|Q|}"
;;
esac
done
参考文献：
http://shouce.jb51.net/shellbook/zh/chapters/01-chapter4.html