awk

Table of Contents

1. Match every lines starting with Link: or [number] except [1]

Link: https://example.com/foobar1

Links:
[1]: https://example.com/foobar1
[2]: https://example.com/foobar4

awk '/^Link:/ || (/^\[[0-9]+\]/ && ! /^\[1\]/) {print $2}' foo.txt

1.1. Print unique links without changing the order of the list

awk '/^Link:/ || /^\[[0-9]+\]/ { if (!seen[$2]++) print $2}' foo.txt

2. Print the total amount from a list of numbers found on the first field ($1)

awk '{sum+=$1} END {print sum}'

3. Print value in matching FIELD= from each lines

awk '{for (i=1; i<=NF; i++) if ($i ~ /FIELD=/) print $i}'

4. Print the last 2 fields, separated by ., return foobar

echo "buz.foo.bar" | awk -F '.' '{print $(NF-1)$NF}'

5. Return first field with the highest number

printf '8,buz\n42,foo\n27,bar' | awk -F, 'NR == 1 { var = $1 } { if ($1 > var ) var = $1 } END { print var }'
#                                         \__________________/ \_________________________/ \_______________/
#                                                  |                        |                      |
#                                         while we are on the    run this on every lines    run this after
#                                         first line, set the                               every lines have
#                                         variable "var" to                                 been processed
#                                         the value of the
#                                         first field $1
#                                         delimited by ","

6. References