shell：从字符串中查找某字符

下面的shell有2个功能：
1）从字符串users中获取单独的user，并重命名
2) 判断user中是否包含特定字符串

#! /bin/sh
users=120_AB_5152109,12_CD_05152128,1205_CC_152153

field_number=`echo $users | awk 'BEGIN{FS = ",";}{print NF}'`
count=1
str="_AB_"

while [ $count -le $field_number ]; do
_user=`echo $users | cut -d ',' -f $count`
count=$(( $count+1 ))
var=$_user.db3
echo $var
echo "$var" |grep -q "$str"
if [ $? -eq 0 ];
then echo find $str in $var
fi
done

输出结果：
120_AB_5152109.db3
find _AB_ in 120_AB_5152109.db3
12_CD_05152128.db3
1205_CC_152153.db3

改良版本，查找多个字符串

#! /bin/sh
users=222_CS_222,098_CH_333,120_AB_5152109,12_CD_05152128,1205_CC_152153

field_number=`echo $users | awk 'BEGIN{FS = ",";}{print NF}'`
count=1

while [ $count -le $field_number ]; do
_user=`echo $users | cut -d ',' -f $count`
count=$(( $count+1 ))
var=$_user.db3
echo $var
for i in "_AB_" "_CH_"
do
echo "$var" |grep -q "$i"
if [ $? -eq 0 ]; then
echo find $i in $var
break
fi
done
done

运行结果：
222_CS_222.db3
098_CH_333.db3
find _CH_ in 098_CH_333.db3
120_AB_5152109.db3
find _AB_ in 120_AB_5152109.db3
12_CD_05152128.db3
1205_CC_152153.db3

更严格的写法

#! /bin/sh
users=222_CS_222,098_CH_333,120_AB_5152109,12_CD_05152128,1205_CC_152153

field_number=`echo $users | awk 'BEGIN{FS = ",";}{print NF}'`
count=1

while [ $count -le $field_number ]; do
_user=`echo $users | cut -d ',' -f $count`
count=$(( $count+1 ))
var=$_user.db3
echo $var
for i in _AB_ _CH_; do
tmp=`echo $var | grep $i | wc -l` 2>./error.txt
if [ $tmp -ne 0 ]; then
echo find $i in $var
break
fi
done
done

参考文档：

http://www.blogjava.net/xzclog/archive/2011/03/04/345712.html