> ## Documentation Index
> Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Delete
> This guide explores how to delete lines from input files using the `sed` command, covering various deletion methods and in-place updates.
Stream Editor (`sed`) is a powerful command-line utility for transforming text in a pipeline. In this guide, we’ll explore how to delete lines from input files using the `d` command, covering non-destructive edits, specific-line removals, range deletions, and in-place updates.
## Table of Contents
1. [Overview of the `d` Command](#overview-of-the-d-command)
2. [Non-Destructive Deletion](#non-destructive-deletion)
3. [Deleting a Specific Line](#deleting-a-specific-line)
4. [Deleting a Range of Lines](#deleting-a-range-of-lines)
5. [In-Place Deletion with `-i`](#in-place-deletion-with--i)
6. [Quick Reference](#quick-reference)
7. [Links & References](#links--references)
***
## Overview of the `d` Command
The simplest way to remove lines in `sed` is with the delete script `d`:
```bash theme={null}
sed 'd' employees.txt
```
This command reads every line and deletes it, producing no output.
Under the hood, `sed` follows this syntax:
```text theme={null}
sed [OPTIONS] SCRIPT [INPUT-FILE...]
```
* **SCRIPT**: A quoted set of editing commands (here, `'d'`).
* **INPUT-FILE**: One or more files to process (defaults to standard input).
Wrap your script in single quotes (e.g., `'d'`) so the shell interprets it literally.
***
## Non-Destructive Deletion
By default, `sed` writes the transformed text to **standard output** and leaves the original file unchanged. To delete line 2 from `employees.txt`:
```bash theme={null}
sed '2d' employees.txt
```
Output:
```text theme={null}
1|Kriti|Shreshtha|Finance|Financial Analyst|kriti.shreshtha@company.com|60000
3|Debbie|Miller|IT|Software Developer|debbie.miller@company.com|80000
4|Enrique|Rivera|Marketing|Marketing Specialist|enrique.rivera@company.com|65000
5|Feng|Lin|Sales|Sales Manager|feng.lin@company.com|90000
6|Andy|Luscomb|IT|IT Manager|andy.luscomb@company.com|95000
7|Mark|Crocker|HR|HR Manager|mark.crocker@company.com|85000
8|Jing|Ma|Engineering|Engineering Manager|jing.ma@company.com|100000
```
Your source file remains intact:
```bash theme={null}
cat employees.txt
```
***
## Deleting a Specific Line
To drop only the sixth line:
```bash theme={null}
sed '6d' employees.txt
```
This command filters out line 6 from the output stream, leaving all others.
***
## Deleting a Range of Lines
Use a comma-separated address pair to remove a block of lines:
```bash theme={null}
sed '3,5d' employees.txt
```
This deletes lines 3 through 5.
Address ranges must ascend (e.g., `3,5d`). Specifying `5,3d` is invalid and will have no effect.
***
## In-Place Deletion with `-i`
To modify the file directly, add the `-i` (in-place) option:
```bash theme={null}
# Inspect original
cat employees.txt
# Delete lines 2 through 7 and save changes
sed -i '2,7d' employees.txt
# Verify result
cat employees.txt
```
Resulting file:
```text theme={null}
1|Kriti|Shreshtha|Finance|Financial Analyst|kriti.shreshtha@company.com|60000
8|Jing|Ma|Engineering|Engineering Manager|jing.ma@company.com|100000
```
On macOS, `sed -i` requires a zero-length extension: `sed -i '' '2,7d' file.txt`. Always back up critical data before in-place edits.
***
## Quick Reference
| Command Syntax | Effect | Example |
| --------------- | ----------------- | ----------------------------- |
| `sed 'd'` | Delete all lines | `sed 'd' employees.txt` |
| `sed 'Nd'` | Delete Nth line | `sed '6d' employees.txt` |
| `sed 'M,Nd'` | Delete line range | `sed '3,5d' employees.txt` |
| `sed -i 'M,Nd'` | In-place deletion | `sed -i '2,7d' employees.txt` |
***
## Links & References
* [GNU `sed` Manual](https://www.gnu.org/software/sed/manual/sed.html)
* [Sed One-Liners Explained](https://www.pement.org/sed/)
* [Shell Quoting Best Practices](https://www.gnu.org/software/bash/manual/html_node/Quoting.html)
By mastering these delete operations, you can efficiently cleanse, filter, or reorganize textual data in scripts and pipelines. Happy editing!