1  字符串的更具字符分割

1） xargs分割

echo "chenyu*hello*word" | xargs -d "*"
chenyu hello word

 

2） awk分割

echo "chenyu*hello*word" | awk -F "*" '{print $1}'
chenyu

 

 

 

 

 

2 字符串的删除字符

1）用tr命令

echo "chenyu ni hao ya" | tr -d 'y' 
chenu ni hao a

2）用sed命令

echo  "hello*word*word" | sed 's/*//g'
hellowordword

 

 

 

 

 

 

 

 

3 文本内容的删除

用sed命令

cat 1.txt
chenyu
nihao
hello
word
chenyu
nihao
dongma
sed -i '/chenyu/d' 1.txt
cat 1.txt
nihao
hello
word
nihao
dongma

 

 

 

 

 

 

 

 

 

 

4 grep -q 用于if逻辑判断

-q 参数，本意是 Quiet; do not write anything to standard output. Exit immediately with zero status if any match is found, even if an error was detected.  中文意思为，安静模式，不打印任何标准输出。如果有匹配的内容则立即返回状态值0

自己测试如下

#/bin/bashvalue="chenyu ni hao ya"#匹配成功执行$?返回0
echo "hello" | grep -q "he";
echo $?
#匹配失败执行$?非0
echo "hello" | grep -q "hehelodaf";
echo $?#如果能匹配成功那么就到then反之到else
if echo $value | grep -q "chenyuddsa"; 
thenecho "first success" 
elseecho "first fail"
fiif echo $value | grep -q "hao"; 
thenecho "second success" 
elseecho "second fail"
fi

允许结果如下：

./grep.sh
0
1
first fail
second success

 

 

 

 

 

 

 

5 grep -i（忽略大小写）来判断结果

#/bin/bashvalue="chenyu"
echo $value | grep -i "chen" > /dev/nullif [ $? -eq 0 ];
thenecho "grep success"
elseecho "grep fail"
fiecho $value | grep -i "chengongyu" > /dev/nullif [ $? -eq 0 ];
thenecho "grep success"
elseecho "grep fail"
fi

运行结果

grep success
grep fail