Write a program that reads a single integer from standard input. If the integer is negative, the program should exit with an error exit code (different than zero). If the integer is zero or positive, the program should exit with a success exit code (zero).
$ ./errxit && echo 'Ok'
-3
$ ./errxit && echo 'Ok'
3
Ok
You can check the exit code from the command line by issuing the echo $? command
or alternatively by running your program followed by && echo 'zero exit code'
which is executed when the program returns 0.
exit to control the exit code;return in main is the exit code;exitSuccess and exitFailure from System.Exit to control the exit code from the IO monad.try next: bytes2bits bits2bytes
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