HP-UX 11i System Administration Handbook and Toolkit, Second Edition

awk

awk can pretty much do it all. With awk, you can search, modify files, generate reports, and a lot more. awk performs these tasks by searching for patterns in lines of input (from standard input or from a file). For each line that matches the specified pattern, it can perform some very complex processing on that line. The code to process matching lines of input is a cross between a shell script and a C program.

Data manipulation tasks that would be very complex with combinations of grep, cut, and paste are very easily done with awk. Because awk is a programming language, it can also perform mathematical operations or check the input very easily ...