LWM-Linux/06 - Linux File Operations/File Searching (find).md

File Searching using find

##1. Basic Syntax: The basic syntax of the find command is: find [path] [expression] # Where [path] is the directory you want to search in, and [expression] defines the search criteria.

2. Searching by Name:

• To find files by name:
  • find /path/to/search -name "filename" # Perform a case-sensitive search "-name"
• Use wildcards for pattern matching:
  • find /path/to/search -name "*.txt"
• For case-insensitive search:
  • find /path/to/search -iname "filename" # Perform a insensitive case search.

3. Searching by Type:

• Find only directories:
  • find /path/to/search -type d
• Find only regular files:
  • find /path/to/search -type f
• Find symbolic links:
  • find /path/to/search -type l

4. Searching by Size:

• Find files larger than 100MB:
  • find /path/to/search -size +100M
• Find files smaller than 1KB:
  • find /path/to/search -size -1k
• Find files exactly 50 bytes:
  • find /path/to/search -size 50c

5. Searching by Time:

• Find files modified in the last 7 days:
  • find /path/to/search -mtime -7
• Find files accessed more than 30 days ago:
  • find /path/to/search -atime +30
• Find files whose status was changed within the last hour:
  • find /path/to/search -cmin -60

6. Searching by Permissions:

• Find files with exact permissions:
  • find /path/to/search -perm 644
• Find files with at least these permissions:
  • find /path/to/search -perm -644

7. Logical Operators:

• AND operation (implicit):
  • find /path/to/search -name "*.txt" -size +1M
• OR operation:
  • find /path/to/search \( -name "*.txt" -o -name "*.pdf" \)
• NOT operation:
  • find /path/to/search ! -name "*.txt"

8. Actions:

• Print results (default action):
  • find /path/to/search -name "*.txt" -print
• Execute a command on found files:
  • find /path/to/search -name "*.txt" -exec cat {} \;
• Delete found files (use with caution):
  • find /path/to/search -name "*.tmp" -delete

9. Limiting Depth:

• Search only in the current directory:
  • find /path/to/search -maxdepth 1 -name "*.txt"
• Limit search to 3 levels deep:
  • find /path/to/search -maxdepth 3 -name "*.txt"

10. Performance Optimization:

• Use '-xdev' to stay on one filesystem:
  • find /path/to/search -xdev -name "*.txt"
• Optimize for large directories:
  • find /path/to/search -name "*.txt" -fprintf /dev/stdout '%p\0' | xargs -0 process

11. Advanced Examples:

• Find all empty directories:
  • find /path/to/search -type d -empty
• Find all files owned by a specific user:
  • find /path/to/search -user username
• Find files and compress them:
  • find /path/to/search -name "*.log" -exec gzip {} +

12. Find Alternatives:

Using locate:

• The locate command quickly searches for files and directories by their names. Here's the basic syntax:

  locate {filename}
  

• For example, to locate a file named resolv.conf, you can run:

  locate resolv.conf