tastiero, please use [code][/code]
tags around your code and data, to preserve formatting and to improve readability. Please do not use quote tags, colors, or other fancy formatting.
Don't bother trying to backslash-escape the contents of the variable itself. Trying to do such generally only leads to frustration.
As grail mentioned, you don't have to use "/
" as the sed "s
" command delimiter; just about any ascii character can be substituted instead. Simply choose one that isn't found in the string itself.
grail used "@
" above, but I personally like to use "|
" myself most of the time.
sed "s|^|$URL|" list.txt
Edit: BTW, since "^
" can only match once per line, the "g
" (global) modifier isn't necessary here. You only need to use it when doing multiple replacements on a single line.