linux shell之字符串的更具字符分割和删除字符和文本内容的删除以及内容是否匹配成功

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/bash
      value="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";
      then
        echo "first success"
      else
        echo "first fail"
      fi
      if echo $value | grep -q "hao";
      then
        echo "second success"
      else
        echo "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/bash
      value="chenyu"
      echo $value | grep -i "chen" > /dev/null
      if [ $? -eq 0 ];
      then
     	echo "grep success"
      else
     	echo "grep fail"
      fi
      echo $value | grep -i "chengongyu" > /dev/null
      if [ $? -eq 0 ];
      then
     	echo "grep success"
      else
     	echo "grep fail"
      fi
  
 

运行结果

      grep success
      grep fail
  
 

文章来源: chenyu.blog.csdn.net，作者：chen.yu，版权归原作者所有，如需转载，请联系作者。

原文链接：chenyu.blog.csdn.net/article/details/88636503