More very useful sed tips for the command line on Linux.
More useful sed tips.
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Easily change files on your Linux system with a simple command.
This command will change the default port for the SSH server on your Linux machine. jason@jason-desktop:~$ perl -pi -e ‘s/^#?Port 22$/Port 443/’ /etc/ssh/sshd_configjason@jason-desktop:~$ perl -pi -e ‘s/^#?Port 22$/Port 443/’ /etc/ssh/sshd_config Then run this command to restart the SSH server. jason@jason-desktop:~$ sudo service ssh restartjason@jason-desktop:~$ sudo service ssh restart This will…
Read MoreConvert text from comma delimited to newline delimited with a simple command.
Some text files are shipped as comma-delimited files. This can be annoying to fix, but it can be done with the Linux command line. Here is an example of comma-delimited text. jason@jason-desktop:~/Documents$ cat banlist.txt | head -c 200 ; echo 10.34.28.4, 103.11.70.143, 103.11.70.143, 103.22.245.6, 107.20.178.108, 108.163.248.74, 108.21.102.146, 108.62.110.25, 108.62.33.114, 108.62.33.114,…
Read MoreTrim multiple spaces with sed into a normal string.
To trim multiple spaces from a sentence and turn it back into properly readable text, use this sed syntax. sed ‘s/ \+/ /g’sed ‘s/ \+/ /g’ This is an example. echo "Hello, this sentence has multiple spaces in it and needs fixing." Hello, this sentence has multiple spaces in it…
Read MoreFun with sed on Linux.
The sed command can be used to reverse text. This is a very interesting feature. Provide a text string, and it will be reversed. jason@jason-Virtual-Machine:~$ sed ‘/\n/!G;s/\(.\)\(.*\n\)/&\2\1/;//D;s/./Hello. /’ <<< ‘This is a long sentence in reverse. This is a lot of fun.’ Hello. .nuf fo tol a si sihT .esrever…
Read MoreSearch and replace text in a file with ed.
I have a text file containing this string. deusexmachina:Documents jason$ cat out Darwin deusexmachina.local 18.2.0 Darwin Kernel Version 18.2.0: Mon Nov 12 20:24:46 PST 2018; root:xnu-4903.231.4~2/RELEASE_X86_64 x86_64deusexmachina:Documents jason$ cat out Darwin deusexmachina.local 18.2.0 Darwin Kernel Version 18.2.0: Mon Nov 12 20:24:46 PST 2018; root:xnu-4903.231.4~2/RELEASE_X86_64 x86_64 And I want to replace…
Read MoreUse sed to filter text, this is very useful.
This sed sample will filter out all HTML opening and closing tags in HTML sed -e ‘s/<[^>]*>//g’ blog.txtsed -e ‘s/<[^>]*>//g’ blog.txt This is an example of the usage of this one-liner. 4.4 Sun Nov 11 jason@Yog-Sothoth 0: $ sed -e ‘s/<[^>]*>//g’ index.php <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">…
Read MoreAnother way to get the actual IP address of your machine.
This is yet another way to get the actual IP address of your Linux machine on a LAN. This returns just the IP address of your Linux computer. jason@jason-Lenovo-H50-55:~$ ip a | awk ‘/inet / { print $2 }’ | sed -n 2p 192.168.1.4/24jason@jason-Lenovo-H50-55:~$ ip a | awk ‘/inet /…
Read MoreVery cool Linux text processing tricks.
Align all text right on an 80 column width. jason@jason-Lenovo-H50-55:~/Documents$ ls -hula | sed -e :a -e ‘s/^.\{1,80\}$/ &/;ta’ total 872K drwxr-xr-x 2 jason jason 4.0K May 4 08:48 . drwxr-xr-x 23 jason jason 4.0K May 3 20:51 .. -rw-r–r– 1 jason jason 848K Apr 21 13:01 altis_insurgency_altis.pbo -rwxrwxr-x 1…
Read MoreSome awesome tricks with awk, grep and sed.
Reading a large text file and then finding all words that contain between 5 and 7 vowels. Notice I am not using cat. jason@Yog-Sothoth:~/Documents$ egrep ‘^([^aieou]*[aieou]){5,7}[^aieou]*$’ < pg768.txt | wc -l 284jason@Yog-Sothoth:~/Documents$ egrep ‘^([^aieou]*[aieou]){5,7}[^aieou]*$’ < pg768.txt | wc -l 284 Count the number of times a single word appears in…
Read MoreHow to use the sed command to filter text files in Linux and other useful shell tricks for the Linux command line.
Using sed to filter a text file and change a specific character for another. In this case the ” character becomes the ‘ character using the magic of the sed command. Since I am using a character the shell also uses I have to escape it out so the command…
Read MoreHow to strip all of the text out of a text file and leave only the numbers and formatting. And other sed tricks.
How to strip all numbers out of a text stream This is how to remove all text from the output of a file and only keep the other formatting. homer@deep-thought ~/Desktop/b $ fortune -l | sed s/[a-z]/\ /gi; : 3:15 . . – . , ! — ’84homer@deep-thought ~/Desktop/b…
Read MoreUseful shell tips. How to search and replace characters or words with the bash shell.
Search and replace on the bash shell is very useful for various one-liner shell commands. The below example shows how to replace a # character with a * character. jason@DESKTOP-R72SPS3:/mnt/c/Users/johnc/Documents$ cat ip.c | sed ‘s/#/*/gi;’ *include <stdio.h> int main() { printf("."); return 0; }jason@DESKTOP-R72SPS3:/mnt/c/Users/johnc/Documents$ cat ip.c | sed…
Read MoreBasic text filtering with sed. Very useful when you are manipulating text files.
This example uses sed to replace the beginning word of a sentence. Administrator@WIN-EM8GK0ROU41 ~ $ echo "this is a line of text." | sed "s/this/This/gi;" This is a line of text.Administrator@WIN-EM8GK0ROU41 ~ $ echo "this is a line of text." | sed "s/this/This/gi;" This is a line of text. This…
Read MoreHow to search and replace text in a file with sed. Not using cat.
The sed command is very useful for searching and replacing text in a file. This is how to search for and replace a text string in a file. Homer@bejiitas ~ $ sed -i ‘s/<main>/<mein>/gi;’ my.cHomer@bejiitas ~ $ sed -i ‘s/<main>/<mein>/gi;’ my.c This is how to search and replace text in…
Read MoreHow to filter text with the sed command. This is useful for various shell tricks.
Using wildcards on the Linux command line This is a standard listing of files with wildcards in the bash shell. homer@deep-thought ~/Documents $ ls *.wad basenew.wad cc4-tex.wad city-heat.wad dark.wad doom.wad plutonia.wad scythe2.wad SKYTEST.wad brick.wad cchest4.wad consoleCopy.wad doom2.wad hexen.wad RIII.wad scythex.wad SODfinal.wadhomer@deep-thought ~/Documents $ ls *.wad basenew.wad cc4-tex.wad city-heat.wad dark.wad doom.wad…
Read MoreConverting a comma delimited file to newline delimited. Using sed to perform the conversion.
The search and replace dialog in Gedit. I have used this to convert a comma-delimited file to a newline delimited file. I had saved a huge long list of IP addresses that I had to put into the ban list on my forums, and the list was comma-delimited, but the…
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