SHELL

delete a line starting with sed

# Delete all lines starting with '#'
$ sed -i '/^#/d' filepath

delete line in sed

# -i here update the file, try with and without -i, 
sed -i -e '/yourpattern/,$d' file # delete everyhing afer the pattern
sed '/yourpattern/d' file   #delete pattern containing line
sed -i -e "/your_pattern/,+2 d" file  # 2 lines after the pattern
sed -i -e "5,5d" file # remove 5th line
sed '10,$d' pes.com # delete everything after 10th line
sed '7,36!d' tmp.com > tmp_coord # specific lines to a file
sed -i '$d' file # delete last line
sed -i -e '29,36d' pes.com delete specific lines 
sed -i -e '78r../../insert_file' File_you_change.txt   #sed interst lines to a file
sed 's/^........//' delete chars 1st to x in ANY line, ... = charachters 

sed remove line

$ sed 's|http://||' <<EOL
http://url1.com
http://url2.com
http://url3.com
EOL