awk

Smth like UNIX SQL. Yup, it’s a whole language.

• How to Use the awk Command on Linux

Print the third column of a space-separated file:

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awk '{print $3}' tables.txt

Print the last column of each line in a file, using a comma as a field separator:

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awk -F ',' '{print $NF}' tables.txt

Print lines that match a condition:

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awk '($10 >= min_value && $10 <= max_value)' tables.txt

Print first, second and last arguments:

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awk '{print $1,$2,$NF}' some_text.txt

• -F - set field separator

• RS - record separator (think “line separator”), \n by default
• FS - field separator, space by default
• NF - number of fields read
• FNR - current record number in FILENAME
• NR - current record number in the total input stream

Records are read one at a time, and stored in the field variable $0. The record is split into fields which are stored in $1, $2, …, $NF.

Data input stored in fields is string, unless the entire field has numeric form and then the type is number and string.

So you can treat it like both:

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echo 24 24E | mawk '{ print($1>100, $1>"100", $2>100, $2>"100") }'
0 1 1 1