Intro to nl Command
The nl
command is a powerful Linux utility designed for line numbering in text files, making it an essential tool for text processing and code analysis. As part of the standard text manipulation toolkit, nl
provides developers and system administrators with a straightforward method to add line numbers to file contents.
Understanding the nl Command
The nl
command (short for "number lines") is primarily used to display text files with line numbers. Unlike simple numbering methods, nl
offers advanced configuration options for precise line numbering across various file types and formatting requirements.
Key Features of nl Command
Feature |
Description |
Line Numbering |
Adds sequential numbers to file lines |
Flexible Formatting |
Supports multiple numbering styles |
Selective Numbering |
Can number specific line types |
Basic Syntax
nl [options] filename
Example Demonstration
Let's explore a practical example on Ubuntu 22.04:
## Create a sample text file
echo -e "First line\nSecond line\nThird line" > sample.txt
## Display file with line numbers
nl sample.txt
This command will output:
1 First line
2 Second line
3 Third line
The nl
command integrates seamlessly with Linux text processing workflows, supporting complex scenarios like code review, log analysis, and file documentation.