The term `awk' refers to a particular program, and to the language you use to tell this program what to do. When we need to be careful, we call the program "the `awk' utility" and the language "the `awk' language." The term `gawk' refers to a version of `awk' developed as part the GNU project. The purpose of this manual is to explain both the `awk' language and how to run the `awk' utility. While concentrating on the features of `gawk', the manual will also attempt to describe important differences between `gawk' and other `awk' implementations. In particular, any features that are not in the POSIX standard for `awk' will be noted.