Master the Linux ‘find’ Command: 7 Real‑World Uses & Interview Solution

The find command is a fundamental tool for Linux backend and operations engineers, and it frequently appears in technical interviews.

Interview question: In a logs directory on a Linux server, delete all log files whose last access time is more than one year old.

Solution: Change to the target directory and run: find . -type f -atime +365 -exec rm -rf {} \; The article then introduces seven practical find usages.

0. Find by name or regular expression

find . -name test.txt

find ./yang/books -name "*.pdf"

Specifying -type f makes the search explicit:

find ./yang/books -type f -name "*.pdf"

1. Find different file types

find . -type d -name "yang*"

find . -type l -name "yang*"

2. Find by timestamps

Linux tracks three timestamps:

atime : last access time.

mtime : last modification time.

ctime : last metadata change time.

Examples:

find . -type f -atime +365

find . -type f -mtime 5

find . -type f -ctime +5 -ctime -10

3. Find by size

Use -size with units: b: 512‑byte blocks (default) c: bytes w: two‑byte words k: kilobytes M: megabytes G: gigabytes

Example – files between 10 MB and 1 GB:

find . -type f -size +10M -size -1G

4. Find by permissions

find . -type f -perm 777

This finds files with read, write, and execute permissions for owner, group, and others.

5. Find by ownership

find . -type f -user yang

6. Execute a command on found files

Use -exec to run a command for each match. The placeholder {} represents the current file, and the command must end with an escaped semicolon \;. find . -type f -atime +5 -exec ls {} \; Without the placeholder, the command would run on all files, not just the matches.

Understanding these patterns makes the original interview question straightforward to solve.