Linux退出状态码

Linux退出状态号码

命令:echo $? 可以读取上一条命令的退出码

案例:

状态码0

yan@yan:~/leran/shell$ ls &> /dev/null
yan@yan:~/leran/shell$ echo $?
0
yan@yan:~/leran/shell$

状态码127

yan@yan:~/leran/shell$ sdadada &> /dev/null
yan@yan:~/leran/shell$ echo $?
127
yan@yan:~/leran/shell$

状态码130

yan@yan:~/leran/shell$ ^C
yan@yan:~/leran/shell$ echo $?
130
yan@yan:~/leran/shell$

状态码126

yan@yan:~/leran/shell$ ls | grep error_code 
error_code
yan@yan:~/leran/shell$ ./error_code &> /dev/null
yan@yan:~/leran/shell$ echo $?
126
yan@yan:~/leran/shell$

shell脚本指定退出码

yan@yan:~/leran/shell$ cat quit_code.sh 
#!/bin/bash

PATH=/home/yan/bin:/home/yan/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
export PATH

code=999

if [ -x test1.sh ]
then
　　code=0
fi

exit $code

yan@yan:~/leran/shell$ ls | egrep "test1.sh|quit_code.sh"
quit_code.sh
test1.sh
yan@yan:~/leran/shell$ chmod 755 quit_code.sh 
yan@yan:~/leran/shell$ ./quit_code.sh 
yan@yan:~/leran/shell$ echo $?
0