Differences

This shows you the differences between two versions of the page.

--- linux_wiki:sed [2016/03/18 23:23]
billdozor [Sed]
+++ linux_wiki:sed [2019/05/25 23:50]
@@ Line 1: / Line 1: @@
-====== Sed ======
-**General Information**
-Stream editor tips and tricks.
-**Checklist**
-  * Distro(s): Any
-  * Package: 'sed' package installed
-----
-====== Print Lines ======
-Different ways to print specific lines.
-Print only line 5 pattern space<code bash>sed -n '5p' /etc/passwd</code>
-  * -n => silent; do not print the entire file
-Line 5, don't delete it<code bash>sed '5!d' /etc/passwd</code>
-  * !d => don't delete
-Print up to line 5, quit and delete the rest of the output<code bash>sed '5q;d' /etc/passwd</code>
-  * q => quit/stop processing more input
-  * d => delete the pattern space (removes all but line 5 from output)
-----
-====== Insert Lines ======
-Insert lines before a found matched pattern.
-Given the contents of /etc/resolv.conf:
-<code bash>
-# Generated by NetworkManager
-nameserver 192.168.1.254
-</code>
-Insert a new DNS entry that will be checked first:
-<code bash>
-sed -i '/nameserver/ i\nameserver 8.8.8.8' /etc/resolv.conf
-</code>
-  * /nameserver/ => pattern to match
-  * -i => in-line editing (changes the file in place)
-  * i\ => insert
-Results in:
-<code bash>
-# Generated by NetworkManager
-nameserver 8.8.8.8
-nameserver 192.168.1.254
-</code>
-===== Insert at first line =====
-Insert also works against line numbers.
-Insert a new comment at line 1:
-<code bash>
-sed -i '1 i\# My first line comment' /etc/resolv.conf
-</code>
-Results in:
-<code bash>
-# My first line comment
-# Generated by NetworkManager
-nameserver 8.8.8.8
-nameserver 192.168.1.254
-</code>
-----
-====== Append Lines ======
-Append lines after a found matched pattern.
-Given the contents of /etc/resolv.conf:
-<code bash>
-# Generated by NetworkManager
-nameserver 8.8.8.8
-nameserver 192.168.1.254
-</code>
-Append a new DNS entry that will be checked 2nd:
-<code bash>
-sed -i '/nameserver 8.8.8.8/ a\nameserver 8.8.4.4' /etc/resolv.conf
-</code>
-Results in:
-<code bash>
-# Generated by NetworkManager
-nameserver 8.8.8.8
-nameserver 8.8.4.4
-nameserver 192.168.1.254
-</code>
-----
-====== Remove Lines ======
-Remove lines that match a pattern.
-Given /etc/resolv.conf:
-<code bash>
-# Generated by NetworkManager
-nameserver 8.8.8.8
-nameserver 8.8.4.4
-nameserver 192.168.1.254
-</code>
-Remove the 8.8.4.4 entry:
-<code bash>
-sed -i '/8.8.4.4/d' /etc/resolv.conf
-</code>
-Results in:
-<code bash>
-# Generated by NetworkManager
-nameserver 8.8.8.8
-nameserver 192.168.1.254
-</code>
-----