grep -r for recursive search in Linux CLI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the -r option do in the grep command?

The -r option tells grep to search recursively through all files in the specified directory and its subdirectories.

beginner

How would you use grep -r to find the word "apple" in all files inside the current directory and its subfolders?

You would run: grep -r "apple" . where . means the current directory.

beginner

True or False: grep -r searches only text files by default.

False. grep -r searches all files, including binary files, unless you add options to exclude them.

intermediate

What is the difference between grep -r and grep -R?

grep -r follows symbolic links only if they are on the command line, while grep -R follows all symbolic links recursively.

intermediate

How can you limit grep -r to search only files with a specific extension, like .txt?

You can combine grep -r with --include="*.txt" like this: grep -r --include="*.txt" "pattern" .

What does the command grep -r 'hello' /home/user do?

A Lists all files in /home/user

B Searches for 'hello' in all files inside /home/user and its subdirectories

C Deletes files containing 'hello' in /home/user

D Searches for 'hello' only in the /home/user directory files, not subdirectories

-r means recursive search through all files and folders inside the given directory.

Which option makes grep follow all symbolic links recursively?

A -v

B -r

C -i

D -R

-R follows all symbolic links recursively, unlike -r.

How do you search recursively for the word 'error' only in files ending with '.log'?

A grep -r 'error' --include='*.log' .

B grep 'error' *.log

C grep -r 'error' *.log

D grep --include='*.log' 'error'

Use --include='*.log' with -r to limit search to .log files.

True or False: grep -r will skip binary files by default.

A False

B True

C Only on Linux

D Only with extra options

grep -r searches all files including binary unless told otherwise.

What symbol represents the current directory when using grep -r?

A ~

B /

C .

D ..

The dot . means the current directory in Linux commands.

Explain how to use grep -r to find a word inside all files in a folder and its subfolders.

Think about how to tell grep to look inside folders and subfolders.

Describe the difference between grep -r and grep -R regarding symbolic links.

Consider how each option treats links to other files or folders.