What are grep and awk?

awk is a very powerful programming language whereas grep is just a filtration tool.^[1]

Many tasks which can be accomplished using grep (typically in conjunction with other commands) can potentially be done using a single awk command.^[1:1]

Basically, whatever grep can do, you can also do in awk. Therefore, you should never see someone using grep and awk together.^[2]

Using grep and awk

grep "foo" file.txt | awk '{print $1}'

Using only awk

awk '/foo/ {print $1}' file.txt

How to use the awk command to…

Search a directory for files or folders with a modified time of today’s date:

ls -lrt --time-style=+'%m-%d-%Y' | awk -v d=$(date +%m-%d-%Y) '$6==d'

How to use the grep command to…

Search a directory for files with a modified time of today’s date:

ls -lrt --time-style=+'%d-%m-%Y' * | grep " $(date +'%d-%m-%Y') "

Tell grep to display file modified time with hours, minutes, and seconds:

ls -lrt --time-style=+'%r %d-%m-%Y' * | grep " $(date +'%d-%m-%Y') "