Linux Command Line & Shell Scripting Flashcards

What does the command tail -f /var/log/syslog do?

Answer: Continuously displays new lines appended to syslog

tail -f follows a file and prints new lines as they are written, useful for live log monitoring.

In a bash for loop, which syntax correctly iterates over the values 1 2 3?

Answer: for i in 1 2 3; do echo $i; done

Bash for loops use the syntax: for variable in list; do commands; done.

Which command prints the current working directory?

Answer: pwd

pwd (print working directory) outputs the absolute path of the current directory.

How do you redirect standard error (stderr) to a file named errors.txt?

Answer: command 2> errors.txt

File descriptor 2 refers to stderr, so 2> redirects error output to the specified file.

What character begins a comment in a bash script?

Answer: #

In bash, everything after # on a line is treated as a comment and ignored by the shell.

Which command makes a shell script named setup.sh executable?

Answer: chmod +x setup.sh

chmod +x adds the execute permission bit for all users on the specified file.

What does the command sort -r file.txt do?

Answer: Sorts file.txt in reverse (descending) order

sort -r reverses the default sort order, displaying lines from Z to A (or largest to smallest).