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tac

Explanation​

The tac command is the reverse of cat. It reads files and prints them to standard output, but it reverses the order of the lines. The last line of the file is printed first, and the first line is printed last. This is particularly useful for reading log files where the most recent entries are at the bottom.

Basic Syntax​

tac [OPTION]... [FILE]...

Common Flags and Options​

FlagDescription
-b, --beforeAttach the separator before instead of after.
-r, --regexInterpret the separator as a regular expression.
-s, --separator=STRINGUse STRING as the separator instead of newline.

Real-world Examples​

  1. View a file in reverse order:

    tac log.txt

  2. View recent log entries first (often piped to head):

    tac /var/log/syslog | head -n 10