标签：权限 参考 text www https 等价 set 使用 检查
学习python风格, 优雅规范书写shell代码
shell中的test命令用于检查某个条件是否成立, 它可以进行整数, 字符串和文件三个方面的判断. test命令通常和if语句一起使用.
test EXPRESSION
# 等价于
[ EXPRESSION ]!! 语法注意:
- 中括号内的每个组件都用空格隔开
- 中括号内的变量用双引号包围起来
非运算
[ ! EXPRESSION ]与运算
[ EXPRESSION1 -a EXPRESSION2 ]
# 等价于
[ EXPRESSION1 ] && [ EXPRESSION2 ]或运算
[ EXPRESSION1 -o EXPRESSION2 ]
# 等价于
[ EXPRESSION1 ] || [ EXPRESSION2 ]| 表达式 | 注释 |
|---|---|
| -z STRING | the length of STRING is zero |
| STRING1 == STRING2 | |
| STRING1 != STRING2 |
| 表达式 | 注释 |
|---|---|
| INTEGER1 -eq INTEGER2 | INTEGER1 is equal to INTEGER2 |
| INTEGER1 -ge INTEGER2 | INTEGER1 is greater than or equal to INTEGER2 |
| INTEGER1 -gt INTEGER2 | INTEGER1 is greater than to INTEGER2 |
| INTEGER1 -le INTEGER2 | INTEGER1 is less than or equal to INTEGER2 |
| INTEGER1 -lt INTEGER2 | INTEGER1 is less than to INTEGER2 |
| 表达式 | 注释 |
|---|---|
| -e FILE | FILE exists |
| -d FILE | FILE is a directory |
| -f FILE | FILE is a regular file |
| -s FILE | FILE has a size greater than zero |
| ... |
| 表达式 | 注释 |
|---|---|
| -r FILE | FILE read permission is granted |
| -w FILE | FILE write permission is granted |
| -x FILE | FILE execute permission is granted |
| -u FILE | FILE SUID bit is set |
| -g FILE | FILE SGID bit is set |
| -k FILE | FILE Sticky bit is set |
| 表达式 | 注释 |
|---|---|
| FILE1 -ef FILE2 | FILE1 and FILE2 have the same device and inode numbers |
| FILE1 -nt FILE2 | FILE1 is newer (modification date) than FILE2 |
| FILE1 -ot FILE2 | FILE1 is older than FILE2 |
标签：权限 参考 text www https 等价 set 使用 检查
原文地址：https://www.cnblogs.com/zakzhu/p/11610752.html
