find Command Linux: Ultimate Guide to Search Files and Directories by Name, Size, and Attributes

The find command is one of the most powerful and versatile tools in Linux for searching files and directories. Whether you’re a system administrator managing large file systems or a developer looking for specific files in your project, mastering find will significantly boost your productivity.

Basic Syntax and Structure

The basic syntax of the find command follows this pattern:

find [path] [expression] [action]

• Path: The starting directory for the search (default is current directory)
• Expression: Criteria for matching files/directories
• Action: What to do with matching results (default is -print)

Finding Files by Name

Exact Name Matching

To find files with an exact name match:

find /home -name "config.txt"

This searches for files named exactly “config.txt” in the /home directory and its subdirectories.

Case-Insensitive Name Search

Use -iname for case-insensitive searches:

find /var/log -iname "ERROR.log"

This will match “error.log”, “Error.log”, “ERROR.LOG”, etc.

Wildcard Pattern Matching

Find all files with specific extensions:

find /home/user/documents -name "*.pdf"
find . -name "*.jpg" -o -name "*.png" -o -name "*.gif"

The -o operator means “OR”, allowing multiple patterns in a single command.

Partial Name Matching

Search for files containing specific text in their names:

find /opt -name "*backup*"
find . -name "test_*_file.txt"

Finding by File Type

The -type option filters results by file type:

find /etc -type f    # Regular files only
find /var -type d    # Directories only
find /dev -type l    # Symbolic links only
find /tmp -type s    # Socket files
find /proc -type c   # Character devices
find /dev -type b    # Block devices

Size-Based Searches

Finding Large Files

find /home -size +100M    # Files larger than 100MB
find /var/log -size +1G   # Files larger than 1GB
find . -size +500k        # Files larger than 500KB

Finding Small Files

find /tmp -size -1M       # Files smaller than 1MB
find . -size -10k         # Files smaller than 10KB

Exact Size Matching

find /home -size 50M      # Files exactly 50MB
find . -size 0            # Empty files

Size Range Searches

find /var -size +10M -size -100M    # Files between 10MB and 100MB

Time-Based Searches

Modification Time

find /home -mtime -7      # Modified in last 7 days
find /var/log -mtime +30  # Modified more than 30 days ago
find . -mtime 0           # Modified today

Access Time

find /tmp -atime +10      # Accessed more than 10 days ago
find /home -atime -1      # Accessed in last 24 hours

Change Time

find /etc -ctime -2       # Status changed in last 2 days

Minute-Based Time Searches

find /var/log -mmin -60   # Modified in last 60 minutes
find /tmp -amin +120      # Accessed more than 120 minutes ago

Permission-Based Searches

Exact Permission Match

find /home -perm 755      # Files with exactly 755 permissions
find /var/www -perm 644   # Files with exactly 644 permissions

At Least Permissions

find /usr/bin -perm -755  # Files with at least 755 permissions
find . -perm -u+x         # Files with user execute permission

Any of These Permissions

find /tmp -perm /222      # Files writable by someone
find . -perm /u+w,g+w,o+w # Files writable by user, group, or other

User and Group Ownership

find /home -user john          # Files owned by user 'john'
find /var -group developers    # Files owned by group 'developers'
find /tmp -uid 1001           # Files owned by UID 1001
find . -gid 100               # Files owned by GID 100

Advanced Search Techniques

Combining Multiple Criteria

Use logical operators to combine search criteria:

# AND condition (implicit)
find /home -name "*.log" -size +1M

# OR condition
find . -name "*.txt" -o -name "*.doc"

# NOT condition
find /tmp -not -name "*.tmp"
find . \! -name "*.bak"

# Complex combinations
find /var/log -name "*.log" -size +10M -mtime +7

Using Parentheses for Grouping

find . \( -name "*.jpg" -o -name "*.png" \) -size +1M

Executing Actions on Found Files

Delete Files

find /tmp -name "*.tmp" -delete
find /var/log -name "*.old" -mtime +30 -delete

Execute Commands

# Execute command for each file
find /home -name "*.bak" -exec rm {} \;

# Execute command with multiple files at once
find . -name "*.txt" -exec grep "pattern" {} +

# Interactive execution
find /tmp -name "core.*" -ok rm {} \;

Copy or Move Files

find /home/user -name "*.pdf" -exec cp {} /backup/pdfs/ \;
find . -name "*.old" -exec mv {} /archive/ \;

Performance Optimization

Limiting Search Depth

find /home -maxdepth 2 -name "*.txt"    # Search only 2 levels deep
find . -mindepth 2 -name "*.log"        # Skip first 2 levels

Faster Searches with locate

For frequently accessed files, consider using locate which uses a pre-built database:

locate filename.txt
updatedb  # Update the locate database

Excluding Directories

find /home -path "*/.*" -prune -o -name "*.txt" -print
find . -name ".git" -prune -o -name "*.py" -print

Practical Examples and Use Cases

System Administration Tasks

Find large log files eating disk space:

find /var/log -type f -size +100M -exec ls -lh {} \;

Clean up old temporary files:

find /tmp -type f -mtime +7 -delete

Find SUID/SGID files (security audit):

find / -perm -4000 -type f 2>/dev/null    # SUID files
find / -perm -2000 -type f 2>/dev/null    # SGID files

Development Tasks

Find all Python files modified today:

find . -name "*.py" -mtime 0

Search for TODO comments in source files:

find . -name "*.js" -exec grep -l "TODO" {} \;

Find duplicate filenames:

find . -type f -printf "%f\n" | sort | uniq -d

File Management

Find broken symbolic links:

find /home -type l ! -exec test -e {} \; -print

Find files by content type (using file command):

find . -type f -exec file {} \; | grep "PDF document"

Regular Expressions with find

Use -regex for more complex pattern matching:

find /var/log -regex ".*\(\.log\|\.txt\)$"
find . -regex ".*/[0-9]+\.jpg$"    # Files like 123.jpg, 456.jpg

Error Handling and Troubleshooting

Suppressing Permission Errors

find /etc -name "*.conf" 2>/dev/null

Verbose Output for Debugging

find /home -name "*.txt" -print0 | xargs -0 ls -la

Alternative Tools and When to Use Them

Best Practices and Tips

• Always test destructive operations first by replacing -delete with -print
• Use quotes around patterns to prevent shell expansion: find . -name "*.txt"
• Be specific with paths to avoid unnecessary directory traversal
• Consider performance when searching large filesystems – use -maxdepth when possible
• Use -print0 with xargs -0 for filenames containing spaces
• Combine with other commands using pipes for powerful workflows

Common Pitfalls to Avoid

• Forgetting to escape special characters in patterns
• Using wrong logical operators – remember -a is implicit AND
• Not handling spaces in filenames properly
• Running destructive commands without testing
• Searching entire filesystem when a specific directory would suffice

The find command is incredibly powerful and versatile. With practice, it becomes an indispensable tool for file system navigation, system administration, and development tasks. Start with simple searches and gradually incorporate more advanced features as you become comfortable with the basic syntax.

Remember to always test your find commands thoroughly, especially when performing actions like deletion or modification. The combination of find with other Unix tools creates a powerful toolkit for managing files and directories efficiently.