Meaning of exit status 1 returned by linux command

Question

What is meaning of exit status 1 returned by linux command? Like 127 exit status indicates \"command not found\".

I have visited http://linux.die.net/abs-guide/exitc

Answer 1

The only general convention is that a zero exit status signifies success, whereas any non-zero exit status is a failure.

Many -- but certainly not all -- command-line tools return exit code 1 for syntax error, i.e. you had too few arguments or an invalid option.

Many -- but, alas, not all -- command-line tools have a manual page. By convention, it should document the exit codes of the program, but many do not.

Answer 2

You can see the value of the exit status using man.

Giving an example below:

man ls

Now search for string exit

Adding screen shot below: