127 Return code from $?

If the IBM mainframe JCL has some extra characters or numbers at the end of the name of unix script being called then it can throw such error.

In addition to the given answers, note that running a script file with incorrect end-of-line characters could also result in 127 exit code if you use /bin/sh as your shell.

As an example, if you run a shell script with CRLF end-of-line characters in a UNIX-based system and in the /bin/sh shell, it is possible to encounter some errors like the following I've got after running my script named my_test.sh :

$ ./my_test.sh
sh: 2: ./my_test.sh: not found
$ echo $?
127

As a note, using /bin/bash, I got 126 exit code, which is in accordance with gnu.org documentation about the bash :

If a command is not found, the child process created to execute it returns a status of 127. If a command is found but is not executable, the return status is 126.

Finally, here is the result of running my script in /bin/bash :

arman@Debian-1100:~$ ./my_test.sh
-bash: ./my_test.sh: /bin/bash^M: bad interpreter: No such file or directory
arman@Debian-1100:~$ echo $?
126

1. go to C:\Program Files\Git\etc
2. open gitconfig with notepad
3. change [core] autocrlf = true To [core] autocrlf = false