RHCSA Essential Command-Line Tools Flashcards

What does the pipe symbol '|' do in a shell command?

Answer: Sends stdout of the left command to stdin of the right command

The pipe operator connects the standard output of one command to the standard input of the next.

Which command would you use to count the number of unique lines in a sorted file?

Answer: uniq -c

uniq -c prefixes each unique line with its count of occurrences after the file has been sorted.

Which find command locates all regular files larger than 100MB under /home?

Answer: find /home -type f -size +100M

find uses -type f for regular files and -size +100M for files strictly larger than 100 megabytes.

What does 'ls -lh' add over 'ls -l'?

Answer: Displays file sizes in human-readable format (KB, MB, GB)

The -h flag makes sizes human-readable by using units like K, M, and G instead of raw bytes.

Which command displays the full path of the currently active shell executable?

Answer: which bash

which searches PATH directories and prints the full path of the named executable.

What is the purpose of the 'tee' command?

Answer: Reads from stdin and writes to both stdout and a file simultaneously

tee splits the output stream so it goes to both the terminal (stdout) and a specified file at the same time.

Which command shows the manual page for the 'cp' command?

Answer: man cp

man displays the manual (man page) for any command available on the system.