what does " ||" mean? ( Double pipe) - Shell Programming and Scripting

robotronic · #3 (**permalink**) 08-30-2007

If the exit status of the first command (cd /tmp) is not 0, then execute the second command (exit 2).
It's the opposite of '&&', where the second command is executed only if the exit status of the preceding command is 0.

For example:

Code:

$ ls this_file_does_not_exist.txt || echo KO
ls: cannot access this_file_does_not_exist.txt: No such file or directory
KO

$ ls this_file_exist.txt && echo OK
this_file_exist.txt
OK