[SOLVED] Find zero values from a file

Issue

I need to find whether any line of my file has a value of 0 in the fifth column. The values in this column are all numbers:

cat /home/vsrchops/Usrlogin_1.csv | awk '{print $5}'
8
8
1
4
2
8
23
61
473
1465
1771
2200

I tried this command:

cat /home/vsrchops/Usrlogin_1.csv | awk '{print $5}' | grep 0

But it matches all lines containing 0, rather than those that are exactly 0:

2200

How do I find values that are exactly zero?

Solution

Firstly, the cat command is unnecessary, since we can use < to redirect AWK's input to read from the file.

We could modify the grep command to match the start and end of line like this:

awk '{print $5}' </home/vsrchops/Usrlogin_1.csv | grep '^0$'

Here, ^ matches the start of a line and $ matches the end of line.

Or we can use grep options to match the whole line:

awk '{print $5}' </home/vsrchops/Usrlogin_1.csv | grep -Fx 0

Either of these will match only those lines that are exactly 0.

---

Alternatively, we could avoid creating the grep process, and do the matching entirely within AWK:

awk '$5 ~ /^0$/ {print $5}' </home/vsrchops/Usrlogin_1.csv

That's probably the simplest and most efficient solution.

Answered By - Øystein Baarnes

Answer Checked By - Marie Seifert (WPSolving Admin)