Practical Examples

# Find all files containing "homework" in their name
locate homework
# Lists all files with "homework" in their path

# Find files containing "report" regardless of case
locate -i report
# Finds "Report.pdf", "REPORT.txt", "weekly_report", etc.

# Find at most 5 PDF files
locate -n 5 "*.pdf"
# Shows only the first 5 PDF files found

# Find all configuration files using regular expressions
locate -r "/etc/.*\.conf$"
# Finds all .conf files in /etc and its subdirectories

# Count how many Python files you have
locate -c "*.py"
# Shows just the number of Python files found

# Update the locate database (do this after creating new files)
sudo updatedb
# Refreshes the database so locate will find new files

Practical Examples

In the practical examples below we assume the find is look in only in the directory it is running in. So starting directory is the current directory, which is denoted by a period (.).

# Find all text files in the current directory
find . -name "*.txt"
# Lists all .txt files in the current directory and subdirectories

# Find large files that might be wasting space
find . -type f -size +100M
# Finds files larger than 100MB in the current directory

# Find files between 10MB and 100MB in size (using "and" logic)
find . -type f -size +10M -size -100M
# Finds files larger than 10MB but smaller than 100MB

# Find files modified in the last week but not in the last day
find . -type f -mtime -7 -not -mtime -1
# Finds files modified between 1 and 7 days ago

# Find recently modified files
find . -type f -mtime -2
# Finds files in the current directory modified in the last 2 days

# Find files with specific permissions
find . -type f -perm 0777
# Finds files with potentially insecure 777 permissions

# Find all empty files and directories
find . -empty
# Lists all empty files and directories in the current directory

# Find files owned by a specific user
find . -user john
# Finds files owned by user 'john'

# Find with complex conditions (find text files NOT owned by root)
find . -name "*.txt" -not -user root
# Finds text files that don't belong to root

# Find either PNG or JPG files (using "or" logic)
find . \( -name "*.png" -or -name "*.jpg" \)
# Finds all PNG or JPG files in the current directory

# Find executable files that are not shell scripts
find . -type f -executable -not -name "*.sh"
# Finds executable files that don't have the .sh extension

# Find files that match multiple criteria (AND example)
find . -type f -user john -and -mtime -30
# Finds files owned by john that were modified in the last 30 days

# Find docx files OR pdf files (OR example)
find . \( -name "*.docx" -o -name "*.pdf" \)
# Finds all Word documents or PDF files

# Find files with complex conditions using AND, OR, and NOT together
find . -type f \( -name "*.java" -o -name "*.py" \) -not -path "*/test/*"
# Finds Java or Python files that are not in test directories

Using -exec

-exec is used to run a command on each file that matches your search criteria. The {} placeholder is replaced with each filename, and \; marks the end of the command.

For Example:

in the code find my_project -type f -exec echo "Processing file: {} " \; the -exec option will run the echo "Processing file: {} " command on each file that matches the search criteria. The {} placeholder is replaced with each filename, and \; marks the end of the command. So for example if there are 3 files in the my_project directory that match the search criteria, the command will be run 3 times, once for each file.

# Find and delete all .tmp files
find /tmp -name "*.tmp" -exec rm {} \;
# The {} is replaced with each filename, and \; marks the end of the command

# Make all shell scripts executable
find ~/scripts -name "*.sh" -exec chmod +x {} \;
# Adds executable permission to all .sh files

# Find and copy all configuration files to a backup directory
find /etc -name "*.conf" -exec cp {} ~/backup/ \;
# Copies each .conf file to ~/backup/

# Find and list details about PDF files
find ~/Documents -name "*.pdf" -exec ls -lh {} \;
# Shows detailed listing of each PDF file

Using xargs

xargs is used to run a command on each file that matches your search criteria. It is often used in combination with find to perform actions on the files you find.

For Example:

in the code find . -name "*.txt" | xargs wc -l the find command will locate all text files in the current directory, and the xargs command will run the wc -l command on each file. The | operator is used to pipe the output of the find command to the xargs command. So for example if there are 3 text files in the current directory, the command will be run 3 times, once for each file.

# Find and delete all .bak files (alternative to -exec)
find /home -name "*.bak" | xargs rm
# Pipes filenames to xargs which runs rm with those filenames as arguments

# Count lines of code in all Python files
find . -name "*.py" | xargs wc -l
# Counts lines in all Python files

# Create a tar archive of all HTML files
find . -name "*.html" | xargs tar -czf html_files.tar.gz
# Archives all HTML files into a single compressed file

# Replace text in multiple files
find . -name "*.txt" | xargs sed -i 's/old text/new text/g'
# Replaces "old text" with "new text" in all text files

Cleaning Up Temporary Files

# Find and remove files older than 30 days in /tmp
find /tmp -type f -mtime +30 -delete

# Explanation:
# This finds all regular files (-type f) in the /tmp directory
# that haven't been modified in more than 30 days (-mtime +30)
# and deletes them (-delete)
# This is a common system maintenance task to free up disk space

Finding and Fixing Permissions

# Find and fix world-writable files
find . -type f -perm -0002 -exec chmod o-w {} \;

# Explanation:
# This finds all regular files in the current directory
# with world-writable permissions (potentially insecure)
# and removes the world-writable bit
# This improves security by preventing unauthorized users from modifying files

Creating a Backup of Important Files

# Back up all configuration files modified today
find . -name "*.conf" -type f -mtime 0 -exec cp {} ~/config_backup/ \;

# Explanation:
# This finds all .conf files in the current directory
# that were modified today (-mtime 0)
# and copies them to a backup directory
# This helps preserve important changes before making system changes