Bash:Test: Difference between revisions
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Created page with "The test command evaluates an expression and sets $? 0 => True/Successful 1 => False/Unsuccessful In if statement test can be executed as [ expression ]. This has better read..." |
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The test command evaluates an expression and sets $? 0 => True/Successful 1 => False/Unsuccessful | The test command evaluates an expression and sets $? | ||
:0 => True/Successful | |||
:1 => False/Unsuccessful | |||
In if | In if statements test can be executed as [ expression ]. This has better readability. | ||
;if [ x${var} = x ] | |||
:Test if var is empty | |||
;-f filename | ;-f filename | ||
:Regular file existence | :Regular file existence | ||
| Line 12: | Line 16: | ||
;-s filename | ;-s filename | ||
:File is bigger than 0 bytes | :File is bigger than 0 bytes | ||
;-z "string" | |||
:String is zero-length | |||
;-n "string" | |||
:String is not zero-length | |||
Latest revision as of 10:43, 11 May 2021
The test command evaluates an expression and sets $?
- 0 => True/Successful
- 1 => False/Unsuccessful
In if statements test can be executed as [ expression ]. This has better readability.
- if [ x${var} = x ]
- Test if var is empty
- -f filename
- Regular file existence
- -e filename
- Any file existence
- -s filename
- File is bigger than 0 bytes
- -z "string"
- String is zero-length
- -n "string"
- String is not zero-length