I was trying to test for noclobber option using: if [ -o noclobber ] but it turned nothing.
I set the noclobber option on using: set +o noclobber.
prompt> cat checkoption.sh
#!/bin/bash
if [ -o noclobber ]
then
echo "Option is on."
fi
prompt>
prompt> set +o noclobber
prompt> set -o | grep noglobber
noclobber on
prompt> ./checkoption.sh
prompt>
Any idea why I am not getting a message here?
Shell options are not inherited between shell sessions, and you are dealing with two shell sessions here:
The shell script will never detect that the option was set in the calling interactive shell session.
Solutions:
Turn your code into a shell function (in e.g. $HOME/.bashrc):
checknoclobber () { [ -o noclobber ] && echo 'Noclobber is on'; }
Or, for the generic case,
checkoption () {
if [ -o "$1" ]; then
printf '%s is set\n' "$1" >&2
return 0
else
printf '%s is not set (or invalid option name)\n' "$1" >&2
return 1
fi
}
Set the option in the script.
Source the script file in the interactive shell with source or with the . command.
noclobberoption is not inherited by the script's shell. Try sourcing it:. ./checkoption.shsourceand.are commands for running a script in the current shell. See unix.stackexchange.com/q/182282/70524