Shell Scripting Flashcards
7 cards from real Linux practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Shell Scripting flashcards as text
Which construct in bash properly iterates over all files in the current directory?
Answer: for f in *; do echo "$f"; done
Using glob `*` directly is safer than parsing `ls` output, which breaks on filenames with spaces.
What does the special variable `$?` represent in a shell script?
Answer: The exit status of the last command
`$?` holds the exit code of the most recently executed foreground command.
How do you redirect both stdout and stderr to the same file in bash?
Answer: cmd > file 2>&1
`2>&1` redirects stderr (fd 2) to wherever stdout (fd 1) currently points, combining both streams.
Which command makes a shell script executable?
Answer: chmod +x script.sh
`chmod +x` adds the execute permission bit to the file.
What is the purpose of `set -e` at the top of a bash script?
Answer: Exit the script immediately on any command error
`set -e` causes the script to exit immediately if any command returns a non-zero exit status.
Which syntax correctly defines a function named `greet` in bash?
Answer: greet() { echo hi; }
In bash, `name() { commands; }` is the standard portable function definition syntax.
What does `$(command)` do in a shell script?
Answer: Captures the command's stdout as a string
Command substitution `$(...)` replaces itself with the standard output of the enclosed command.