In awk, you can find and replace values in specific fields using the sub() function.
The sub() function has the following syntax:
sub(regex, replacement, target)
regexis a regular expression that defines the pattern to search for in the target.replacementis the string that will replace the pattern in the target.targetis the variable or expression that the function will operate on.
Here’s an example of how you can use the sub() function to find and replace values in fields:
awk '{sub(/old_value/,"new_value",$field_number); print}' file.txt
This command will find and replace old_value with new_value in the field_number field of each line in the file.txt file. The result will be printed to the standard output.
Note that you can use the gsub() function to perform a global find and replace, replacing all occurrences of the pattern in the target. The gsub() function has the same syntax as sub().