RHCE Scripting and Task Scheduling 2

Question 1

What does the `at` command do?

Accepted Answer

Runs a command at a specific future time once

Answer

The `at` command schedules a command or script to run once at a specified future time, unlike cron which runs jobs repeatedly.

Question 2

Which command in bash reads user input and stores it in variable `NAME`?

Accepted Answer

read NAME

Answer

The `read` built-in command reads a line from standard input and assigns it to the specified variable.

Question 3

What does `2>&1` do in a bash command?

Accepted Answer

Redirects stderr to stdout

Answer

`2>&1` redirects file descriptor 2 (stderr) to wherever file descriptor 1 (stdout) currently points.

Question 4

Which bash construct tests if a variable `$FILE` exists as a regular file?

Accepted Answer

if [ -f $FILE ]

Answer

The `-f` test operator returns true if the specified path exists and is a regular file.

Question 5

What does the `#!/usr/bin/env bash` shebang offer over `#!/bin/bash`?

Accepted Answer

Portability — uses the first `bash` found in PATH

Answer

`#!/usr/bin/env bash` uses `env` to locate `bash` in the PATH, making the script more portable across systems where bash may not be at `/bin/bash`.

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