# You can use awk's field separator (-F) following way: $ cat file google.com/funny unix.stackexchange.com/questions isuckatunix.com/ireallydo
# To explicitly delete everything that comes after ".com", just tweak your existing sed solution to replace ".com(anything)" with ".com": sed 's/\.com.*/.com/' file.txt
$ cat file | awk -F '\\.com' '{print $1".com"}' google.com unix.stackexchange.com isuckatunix.com