awk

There are a few options under Gentoo gawk (default GNU awk), mawk (often faster than gawk) or nawk. They mostly all work the same. Tons of tutorials out there and it really depends on what you want to get done, a simple-ish overview and good guide is Steve's Awk Acadamy.

If you want to sort a file or list based on a particular column you can place the desired column at the start, pipe to sort and then remove the column

awk -F, '{ print $3, $0 }' user.csv | sort | sed 's/^.* //'

Alternatively you can use sort directly…

sort -t, -nk3 user.csv

# Print the 12th column ('{print $12}') of a comma separated file (-F,) called my_file.csv
awk -F, '{print $12}' my_file.csv
# As above but for multiple files and include the filename (FILENAME)
awk -F, '{print FILENAME,$12}' *.csv

# Search for two delimiters (can be regular expressions, hence escaping the period)
awk -F'.|,' '{print $1 "\t" $13}' my_file.csv 

Source

awk -F $'\t' ' { t = $1; $1 = $2; $2 = t; print; } ' OFS=$'\t' input_file

• @bork awk
• awk One-Liners Explained (Part One)
• awk One-Liners Explained (Part Two)
• awk One-Liners Explained (Part Three)
• awk One-Liners Explained (Bonus)