Comprehensive Guide to the find Command in Linux: Search Files with Ease

Introduction

find Command in Linux is used to find files and directories and take action on them. It is one of the most versatile commands in UNIX-like OSes(Linux, BSD). This command should be in the toolset of every developer, sys-admin or anyone interacting with the system.

Basic mastery over this command can simplify a developer’s (DevOps, sys-admins) life. On the surface, it might seem like a difficult and complex command but it is well-structured and fun to use.

In this post you will also learn how find command can be used to delete many files and directories that can’t be done through rm command.

Prerequisites

Introduction to Linux Commands

See How easy, simple, and short it is to use the find command.

Synopsis of the find command in Linux

find [-H | -L | -P] [-EXdsx] [-f path] path ... [expression]
find [-H | -L | -P] [-EXdsx] -f path [path ...] [expression]

Understanding the Basics of the Find Command

At its core, the find command scans through one or more directories and evaluates each file and directory against an expression you provide. It returns every file name that matches this expression. The basic syntax of the find command is as follows:

find [options] [path...] [expression]

• options: Modify the behavior of the find command.
• path: Specify the directory to start the search. If no path is specified, it defaults to the current directory.
• expression: Dictate what to search for and what to do with the matched items.

Key Options and How to Use Them

1. Searching by Name

The -name option allows you to specify the name of the files you want to search for. It’s case-sensitive by default, but you can use -iname for a case-insensitive search.

find /home/user -name "sample.txt" find /home/user -iname "Sample.TXT"

2. Searching by Type

You can find files of a specific type using the -type option. Common types include:

• f for regular files
• d for directories
• l for symbolic links

find /var/log -type f find /home -type d

3. Searching by Modification Date

The find command can search files based on when they were last modified:

• -mtime n: Files modified n*24 hours ago.
• -mtime +n: Files modified more than n days ago.
• -mtime -n: Files modified less than n days ago.

find /home/user -mtime -7 # Files modified in the last week

4. Searching by Size

To find files based on their size, use the -size option. You can specify sizes in kilobytes (k), megabytes (M), gigabytes (G), and others.

find / -size +100M # Files larger than 100 MB

5. Using Logical Operators

Combine conditions using logical operators:

• -and: Both conditions must be true (implicit if omitted).
• -or: Either condition is true.
• -not: Negates a condition.

find /home/user -type f -not -name "*.txt"

6. Executing Commands on Found Files

The -exec option allows you to run a command on each file found. Use {} to represent the current file, and \; to terminate the command.

find /tmp -type f -name "*.tmp" -exec rm {} \;

7. Finding Files by Permissions

To find files with specific permissions, use the -perm option.

find /home/user -perm 644

8. Advanced Searches

Combine multiple search criteria for more refined searches. For instance, finding all .jpg files that are larger than 1MB and modified in the last 30 days:

find / -type f -name "*.jpg" -size +1M -mtime -30

Usage

Example 1 – Find all text files (.txt) extension in the current directory

Solution

find . -name "*.txt"

Explanation – We are using the find command to find files, next we are specifying. (. means current directory) to find in the current directory only, further, we are filtering the search for text files only (with *.txt).

Challenges in using the find command

Not able to correctly break down the problem statement

Not able to solve those sub-problems broken in the previous steps

Difficulty in constructing the find command for the given problem

Right approach for using the find command

Understand the problem well. Any difficult or complex problem related to Linux commands should be approached with a divide-and-conquer strategy.

Divide – Break the problem into sub-problems

Conquer – Solve sub-problems and merge sub-solutions to arrive at the final solution.

In the context of find command, you should first solve the base problem (finding the required files), then keep adding difficult (taken from the problem) one at a time and finally construct the complete find command (solution).

Let us learn this with an example.

Let us understand this with an example

Q1 – find all log files (.log extension) greater than 5MB and older than 10 days in /var/log directory

Approach

Break down the problem
find all log files (.log extension)
greater than 5MB
older than 10 days
directory – /var/log
Tip – Breaking down the problem is 80% of the solution

Solution:
We need to find files -> Use the find command
Command -> find
We need to find files in a given directory -> search only in the given directory
Command -> find /var/log
We need to find only log files -> Use pattern matching to filter log files -> -iname “*.log”
Commad -> find /var/log -iname "*.log"
We need to find files greater than 5 MB -> add a filter for file size
Command -> find /var/log -iname "*.log" -size +5M
We need to find files older than 10 days -> add a filter for time
Command -> find /var/log -iname "*.log" -size +5mb -mtime +10

Final Command

find /var/log -iname "*.log" -size +5mb +mtime 10
# if you face permission issue in /var/log directory then elevate priviledge using sudo
Command - find /var/log -iname "*.log" -size +5mb +mtime 10

Practical Examples and Common Use Cases of Find Command

Example 1: Cleanup Temporary Files

Automatically find and remove temporary files that haven’t been accessed in the last 10 days:

find /var/tmp -type f -atime +10 -exec rm {} \;

Example 2: Archiving Old Files

Find all log files older than a year and archive them:

find /var/log -name "*.log" -mtime +365 -exec tar -rvf yearly_logs.tar {} \;

Example 3: Permission Auditing

Audit files to ensure sensitive files are not world-readable:

find /secure -type f -perm -o=r

Usecases

Find a file in a given directory or its sub-directory

Question 1 – Find a file example.txt in the ~/Downloads directory.

Answer – find ~/Downloads -iname "example.txt"

find command power over other commands

Find older log files and delete them

Question 1 – find more than 2 days older system.log files (files matching with system.log) in /var/log directory and delete them

Answer – First let us find system.log files older than 2 days (modified more than 2 days ago)

find /var/log -iname "system.log.*" -mtime +2

Note: Please don’t use trailing / in the directory name above (e.g /var/log/)

Now, to delete the required found files use -delete option in the find command

find /var/log -iname "system.log.*" -mtime +2 -delete

The above command will throw an error due to a permission issue, so use the sudo

Final command – sudo find /var/log -iname "system.log.*" -mtime +2 -delete

Validation – Again run the find command without the delete option to confirm whether the required files were deleted or not.

Validation command – find /var/log -iname "system.log.*" -mtime +2

See the below screenshot for the complete run of the command

How to use chatgpt or Gemini to solve problems related with find command

Chatgpt or Gemini is a great AI assistant to make our lives easy. If used correctly it can offload 80% of our tasks related to coding, DevOps, and other general tasks as well.

The advent of chatgpt is a paradigm shift in the landscape of programming or system-related tasks. This is going to change the way we solve programming problems, design systems, and troubleshoot issues for always. So please give it a try.

If you can master prompt engineering then it can increase your output 10x.

Let us learn prompt engineering to solve problems related to the find command.

Problem 1 – Find empty files in the ./test folder.

Solution – Simply prompt the above problem to chatgpt as below.

Copy the command and execute on the system

Problem 2 – find files more than 10 MB and older than 5 days in /var/log/nginx and zip them and move them to ~/archive/nginx folder

Solution – First prompt chatgpt with the above problem, understand the solution, then try it
If the provided solution has any issues then again prompt chatgpt the issue until the solution completely works.

FAQs

What is the basic syntax of the find command in Linux?
The basic syntax is find [path] [expression], where you specify the directory path and search criteria.

How can I use find to search by file type?
Use -type followed by f for files or d for directories, e.g., find /path -type f.

Can find search by modification date?
Yes, use options like -mtime or -mmin to filter by modification time.

How do I search for files by name?
Use -name or -iname (case-insensitive) with the filename pattern, e.g., find /path -name "*.txt".

Can I delete files directly with find?
Yes, by adding -exec rm {} \; to the command, but be cautious as this is irreversible.

Conclusion

In this post, You learned about the find command, how to solve related problems, and finally how to construct the find command for the given Problem.

Related Posts

• Introduction to the Linux Operating System

Editorial Team