This script takes every integer passed to it and prints it to standard output as an integer formatted according to US English convention. That is, numbers with more than three digits are printed with every three digits from the right separated by a comma.

print-formatted-integers.sh

#!/usr/bin/bash
#
# This script takes every integer passed to it and prints it to standard output
# as an integer formatted according to US English convention. That is, numbers
# with more than three digits are printed with every three digits from the right
# separated by a comma.
#
# This command was run via the command-line, not as an actual shell script. This
# gist is just a way for me to remember how I did it.
#
# The memory-numbers.txt file contains the following data.
#
#   128974848
#   2147483648
#   128974848
#   1073741824
#   3145728000
#   4724465664
#   128974848
#   4116774912
#   6291456000
#
# This command results in the following output.
#
#   128,974,848
#   2,147,483,648
#   128,974,848
#   1,073,741,824
#   3,145,728,000
#   4,724,465,664
#   128,974,848
#   4,116,774,912
#   6,291,456,000
#
# It could also be used as follows:
#
#   echo -e "82771968\n3145728000" | perl -nE 'chomp;my $value = $_;while ($value =~ s/(\d+)(\d{3})/$1,$2/) {} print "$value\n";'
#
# This example would result in the following output:
#
#   82,771,968
#   3,145,728,000
#
perl -nE 'chomp;my $value = $_;while ($value =~ s/(\d+)(\d{3})/$1,$2/) {} print "$value\n";' memory-numbers.txt