LFCS Question #733: Real Exam Question with Answer & Explanation

Question

What is the purpose of the Bash built-in export command?

Options

• AIt allows disks to be mounted remotely.
• BIt runs a command as a process in a subshell.
• CIt makes the command history available to subshells.
• DIt sets up environment variables for applications.
• EIt shares NFS partitions for use by other systems on the network.

Explanation

The Bash export command is used to mark an environment variable to be passed to child processes.

Common mistakes.

• A. Exporting disks for remote mounting typically involves services like NFS or Samba, not the Bash export command.
• B. Running a command in a subshell is done by enclosing the command in parentheses (command) or using bash -c 'command', not by the export command.
• C. The command history is managed by the shell itself and can be configured through variables like HISTFILE or HISTSIZE, but export does not make it directly available to subshells.
• E. Sharing NFS partitions is handled by the NFS server daemon and configured in /etc/exports, not by the Bash export command.

Concept tested. Bash shell environment variables, export command

Reference. https://www.gnu.org/software/bash/manual/bash.html#index-export

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