Operator usage in bash shell
企业开发
2018-05-13 03:59:31
阅读次数: 2
Common Bash comparisons
Operator Meaning Example
-z |
Zero-length string |
[ -z "$myvar" ] |
-n |
Non-zero-length string |
[ -n "$myvar" ] |
= |
String equality |
[ "abc" = "$myvar" ] |
!= |
String inequality |
[ "abc" != "$myvar" ] |
-eq |
Numeric equality |
[ 3 -eq "$myinteger" ] |
-ne |
Numeric inequality |
[ 3 -ne "$myinteger" ] |
-lt |
Numeric strict less than |
[ 3 -lt "$myinteger" ] |
-le |
Numeric less than or equals |
[ 3 -le "$myinteger" ] |
-gt |
Numeric strict greater than |
[ 3 -gt "$myinteger" ] |
-ge |
Numeric greater than or equals |
[ 3 -ge "$myinteger" ] |
-f |
Exists and is regular file |
[ -f "$myfile" ] |
-d |
Exists and is directory |
[ -d "$mydir" ] |
-nt |
First file is newer than second one |
[ "$myfile" -nt ~/.bashrc ] |
-ot |
First file is older than second one |
[ "$myfile" -ot ~/.bashrc ] |
转载自sunxboy.iteye.com/blog/2000385