How can the existing environment variable FOOBAR be suppressed for the execution of the script./myscript only?
How can the existing environment variable FOOBAR be suppressed for the execution of the script./myscript only?
To suppress the existing environment variable FOOBAR for the execution of a script without affecting other environment variables, the most appropriate method is to use the env command with the -u option. The command 'env -u FOOBAR ./myscript' unsets the FOOBAR environment variable only for the duration of the script execution and doesn't impact other environment variables. Thus, FOOBAR will not be available within the script.
The correct answer is: A. unset -v FOOBAR; ./myscript Explanation: The unset command is used to remove variables or functions from the environment. unset -v FOOBAR: This removes the variable FOOBAR from the environment before running the script ./myscript. Since environment variables are passed down to child processes (like the script execution), this ensures that FOOBAR will not be visible within the script. The other options are incorrect because: C. env -u FOOBAR ./myscript: This command is used to unset an environment variable within the execution environment of a specific command, but not before it. So FOOBAR would still be visible to the script briefly. B. set -a FOOBAR=""; ./myscript: This command sets FOOBAR to an empty string, but doesn't unset it. D. env -i FOOBAR ./myscript: This command would run the script with a completely empty environment, removing all other environment variables as well.