Field Processing: awk

awk is a powerful text-processing language built into Linux. At its simplest, it splits each line into fields and lets you print the ones you want.

By default, awk splits on whitespace. Fields are numbered $1, $2, $3, etc. $0 is the entire line.

awk '{print $1}' crew.txt

This prints only the first word of each line.

Printing multiple fields

awk '{print $1, $3}' data.txt

The comma inserts a space between fields in the output.

Custom field separator with -F

If your data uses a different delimiter (like a colon), tell awk:

awk -F: '{print $2}' /etc/passwd

This splits on : and prints the second field.

Adding text

awk '{print "Name:", $1}' crew.txt

Name: Voss
Name: Tanaka

You can mix literal strings and field variables freely inside the print statement.

Mission: Sensor Data Extract

Engineering has requested a quick readout of sector names and their sensor values. They do not need the reading type column cluttering the display.

1. Use awk to print only columns 1 and 3 from sensors.dat (sector and value), and display them.
2. Save that two-column extract into a new file called readout.txt.
3. Create a folder called sensor-log and move readout.txt into it.
4. Sort the saved readout numerically by the second column so the lowest sensor value appears first.

Expected result

sensor-log/readout.txt holds each sector name followed by its numeric value, separated by a space.