Sept 6, 2023.

AWK is very useful and powerful for pattern extraction, match, print or in other words file manipulations, simple to use and get the job done.

1: Split line and print fields, try: cat list.txt | awk '{print $1, $2}'

2. Extract pattern from file and do sum of all entries matching the pattern, try: grep ” Sequential ” idle_power.txt | awk ‘{sum += $3} END {print sum}’

Here $3 represents which column is to get sum of. Idea is to grep a certain pattern from file from each line and then process output by awk to get sum of column 3. idle_power.txt:

2.345E-6 3.45E-4 1.6078E-3 Sequential …

1.345E-6 2.45E-4 3.6078E-3 Sequential …

3. Count a pattern match – in this example HARRISH to be matched in file.txt, try:awk ‘/HARRISH/{sum++} END {print “Count = “, sum}’

4. Split line and then print – in this example split with “:” and print 5th column, try: awk ‘{split ($0, a, “:”); print a[5]}’

$0 – gets whole line, a – array contains split column value per line, : – separator for split, default is space.

5. Find a pattern from file, print certain columns, and sort the output, try: grep “Leprofesseur” file.txt | awk ‘{print $1, $2, $5}’ | sort | uniq -c