I have a script to download video from youtube but i want to add ss just after the www. to it will be converted into www.ssyoutube.com
#!/bin/bash
dialog --inputbox "Enter Video's Link..." 10 30 2>/tmp/video.txt
video=`cat /tmp/video.txt`
edit=ss
echo $video
sleep 5;
wget $video
Parameter Expansion can do this for you in bash.
video="www.youtube.com"
edit="ss"
video="${video/www./www.$edit}"
echo "$video" # www.ssyoutube.com
man bash → search for "Pattern substitution."
(Sure, sed works too, but for a simple string substitution it's much more efficient to use bash's built-in feature than to fork a new process.)
You could use sed. Use a escaped dot in your regex to match a literal dot.
sed 's/www\./www.ss/g' file
ie,
sed -i 's/www\./www.ss/g' /tmp/video.txt
