1
yesterday i was looking at my cygwin bin folder and i found a exe name [.exe when i execute it , it says "[ : missing ]" like this -
when i execute it with ']' as a argument , it outputs nothing , could you please explain what this is?
Aurelian
Posted 2016-12-10T21:51:55.910
Reputation: 113
2
It’s an alias for test. See man 1 test:
Name
test - check file types and compare values
Synopsis
test EXPRESSION
test
[ EXPRESSION ]
[ ]
[ OPTION
The test command is sometimes used together with if to create a conditional block. It’s also useful on its own:
[ ! -d myDirectory ] && mkdir myDirectory
This would test whether a directory “myDirectory” does not exist and create it if that’s true.
Because it’s (also) for conditions, it must not print anything. Instead, it communicates via exit codes.
This command exists on virtually all GNU/Linux systems and many Unix variants.
See here for a more in-depth explanation.
Daniel B
Posted 2016-12-10T21:51:55.910
Reputation: 40 502