AWK variables

We saw how to use data fields such as $1 and $2. Also, we saw the NR field, which holds the number of processed lines, but there are more built-in variables that AWK offers to simplify work more and more.

• FIELDWIDTHS: Specifies the field width
• RS: Specifies the record separator
• FS: Specifies the field separator
• OFS: Specifies the output separator, which is a space by default
• ORS: Specifies the output separator
• FILENAME: Holds the processed file name
• NF: Holds the line being processed
• FNR: Holds the record which is processed
• IGNORECASE: Ignores character case

These variables can help you a lot in many cases. Let's assume that we have the following file:

John Doe
15 back street
[phone]
    
Mokhtar Ebrahim
10 Museum street
[phone]  

We can say that we have two records for two persons and each record contains three fields. Let's assume that we need to print the name and the phone number. So how do we make AWK process them correctly?

In this case, the fields are separated by a...