Cheat Sheet #day58 - tail

tail Command Cheatsheet

The tail command in Unix-like operating systems is used to display the last part of a file. Here’s a quick reference guide:

Basic Syntax

tail [OPTION]... [FILE]...

Common Options

• -n NUM, --lines=NUM: Output the last NUM lines. Default is 10.

    tail -n 20 file.txt
  

• -c NUM, --bytes=NUM: Output the last NUM bytes.

    tail -c 100 file.txt
  

• -f, --follow: Output appended data as the file grows. Useful for monitoring log files.

    tail -f /var/log/syslog
  

• -F, --follow=name --retry: Similar to -f, but will try to reopen the file if it is moved or rotated.

    tail -F /var/log/syslog
  

• -q, --quiet, --silent: Never output headers giving file names.

    tail -q file1.txt file2.txt
  

• -v, --verbose: Always output headers giving file names.

    tail -v file.txt
  

Examples

1. Display the last 10 lines of a file:

    tail file.txt
   

2. Display the last 20 lines of a file:

    tail -n 20 file.txt
   

3. Display the last 100 bytes of a file:

    tail -c 100 file.txt
   

4. Follow a log file in real-time:

    tail -f /var/log/syslog
   

5. Follow a log file and retry if it is rotated:

    tail -F /var/log/syslog
   

6. Display the last 10 lines of multiple files:

    tail file1.txt file2.txt
   

7. Display the last 10 lines of multiple files with headers:

    tail -v file1.txt file2.txt
   

8. Quiet mode for multiple files without headers:

    tail -q file1.txt file2.txt
   

Additional Information

• Display help:

    tail --help
  

• View tail manual page:

    man tail
  

This cheatsheet covers the essential options and usage scenarios for the tail command. For more advanced features, refer to the man page or use tail --help.