Sequential grep that preserves the order of the list of patterns provided

sequencial.grep.sh

# https://stackoverflow.com/questions/21908809/grep-f-file-to-print-in-order-as-a-file
# You can pipe patt.grep (pattern) to xargs, which will pass the patterns to grep one at a time.
# By default xargs appends arguments at the end of the command. But in this case, grep needs myfile.log to be the last argument. So use the -I{} option to tell xargs to replace {} with the arguments.
# foobar here is the placeholder

# This is useful as grep
cat patt.grep | xargs -Ifoobar grep foobar myfile.log