How can I check if a field is greater than a certain number if that field has a $ sign in front?

Question

Given a file called employee.txt in the format (Firstname, Lastname, Salary) with space as the field separator:

Foo Bar $1,000
First Last $5,550
Abc Def $3,000
Stack Overflow $6000
Help Please $4700

I want to print lines that have its third field greater than $4,000. Desired output:

First Last $5,550
Stack Overflow $6000
Help Please $4700

I am unsure how to check if a field is greater than 4000, for instance, with the $ and , in it.

I've tried using sed to substitute $ and , with blanks then redirect to awk but I want the output to contain $ and , like the original.

Is this doable with awk?

Answer 1

$ awk '{v=$3; gsub(/[$,]/, "", v)} v+0>4000' employee.txt 
First Last $5,550
Stack Overflow $6000
Help Please $4700

How it works

1. v=$3

   Save the third field as variable v.

2. gsub(/[$,]/, "", v)

   Remove the problematic characters from v,

3. v+0>4000

   Print lines for which v is greater than 4000.

Printing a range of values

To print all lines with a value greater than 4000 and less than 5000:

$ awk '{v=$3; gsub(/[$,]/, "", v)} v+0>4000 && v+0<5000' employee.txt 
Help Please $4700