line-rs

line-rs is a simple command-line tool to extract specific lines from a text file without hacks like head -n 5 filename.txt | tail -n +2.

Features

Line Selection

line-rs supports three main ways to select lines:

1. Select a single line:

line -n=5 file.txt

2. Select a range of lines (both ends are included):

line -n=2:4 file.txt # 2, 3, 4

3. Select multiple specific lines:

line -n=2,4,6 file.txt

You can also combine the above! The command bellow selects the line 2 and the range 4:6.

line -n=2,4:6 file.txt # 2, 4, 5, 6

Advanced Line Selection

line-rs supports line selection in a powerful way. If you are familiar with Python syntax, the following should be familiar as well:

• Negative indexing:

  • Select the last line:

    line -n=-1
    

  • From line 3 up to the 2 line from the end:

    line -n=3:-2
    

• Unbounded Ranges:

  • From line 3 up to the end of the file:

    line -n=3:
    

  • From the begining of the file up to line 9:

    line -n=:9 # equivalent to 1:9
    

  • All lines, equivalent to cat:

    line -n=:
    

• Steps:

  • From line 3 up to 9, jumping two lines at a time:

    line -n=3:7:2 # 3, 5, 7
    

  • From line 9 up to 3, jumping backwards:

  line -n=5:3:-1 # 5, 4, 3
  

  • Reverse all lines:

  line -n=::-1
  

You can also skip lines easily:

• Print all line except 5 and 7:

  line --skip=5,7
  

• Print line 2 onwards, skipping lines 6, 7, and 8:

  line -n=2: --skip=6:8
  

Pretty Printing

More about that soon

Json Output

The output can be serialized as JSON, useful for piping and scripts

line -n=2,4 --json # one line, useful for piping
line -n=2,4 --pretty-json

Output:

{
  "source": "file.txt", // or "stdin"
  "lines": [
    { "number": 2, "content": "hi" },
    { "number": 4, "content": "hello" }
  ]
}

line -n=2,4 --array

Output

["hi", "hello"]

line -n=2,4 --json-line

Output

{"number":2,"content":"foo"}
{"number":4,"content":"bar"}

🔧 Installation

More about that soon

Using Cargo

Using pip

Using apt

Using brew

Shell Complition

More about that soon

Examples

# Print line 5
line -n=5 notes.txt

# Print lines 3 to 7
line -n=3:7 notes.txt

# Print lines 2, 4, and 6
line -n=2,4,6 notes.txt

# Print line 1 from stdin
echo -e "a\nb\nc" | line -n=1 -

🛠 Motivation

This tool simplifies extracting lines from a file or stream without relying on brittle chains like:

cat file.txt | head -n=4 | tail -n=1

line-rs gives you a cleaner and more flexible alternative.

📃 License

MIT

💬 Feedback

Feel free to open issues or suggestions on GitHub.

Let me know if you'd like me to add sections for contributing, testing, or packaging (e.g., Debian, Homebrew, etc).