Learning AWK Programming

NR and NF

NR and NF are set each time a new record is read.

AWK sets the variable NR whenever a new record from input file is read. It's value represent the number of current input record being processed by AWK. It is generally used to number the records in a file. For example, to print the number of records with each record in the output from the emp.dat file, we can use it as follows:

$ awk '{ print NR "." $0 }' emp.dat

The output of the execution of the preceding code is as follows:

1.Jack    Singh   9857532312  [e-mail]      M   hr      20002.Jane    Kaur    9837432312  [e-mail]      F   hr      18003.Eva     Chabra  8827232115  [e-mail]       F   lgs     21004.Amit    Sharma  9911887766  [e-mail]      M   lgs     23505.Julie   Kapur   8826234556  [e-mail]     F   Ops     25006.Ana Khanna ...