[Sed] Sed the sed file

Purpose:
Remove hash (#) at front of the line
sed -e '^#' -i xxx.txt

Remove space / tab line
sed -e '^$' -i xxx.txtPurpose:

I want replace some string in another sed file.
So I create another sed file to replace some string which I want.

Create a Sed file is called abc.txt
sed 's|>'"$var"'|>'"$Do"'|g'  -i abc.txt

Create another Sed file is called bcd.txt
Before_Do_Happy=">'\"\$var\"'\|>'\"\$Do\"'"
After_Do_Happy=">'\"\$var\"'<\|>'\"\$Do\"'<"

sed 's|'"$Before_Do_Happy"'|'"$After_Do_Happy"'|g'  -i bcd.txt

Grep piping into sed, replacing inline
grep -rl "general.js" . | xargs   sed  -i   's|general.js|js\/general.js|g'

To remove all blank line & whitespace (include tabs)
sed -e '/^$/d' -i Happy.asp      # To remove all blank lines
sed -e 's/^[ \t]*//' -i Happy.asp # To remove all whitespace (including tabs) from left to first word

Reference:

• Replace a String in Multiple Files in Linux Using Grep and Sed
• sed tip: Remove / Delete All Leading Blank Spaces / Tabs ( whitespace ) From Each Line