The general appearance of font-locking in AWK mode is much like in any other programming mode. See Faces for Font Lock in GNU Emacs Lisp Reference Manual.
The following faces are, however, used in a non-standard fashion in AWK mode:
This face was intended for variable declarations. Since variables are
not declared in AWK, this face is used instead for AWK system
variables (such as
NF) and “Special File Names” (such as
This face is normally used for preprocessor directives in CC Mode.
There are no such things in AWK, so this face is used instead for
standard functions (such as
As well as being used for strings, including localizable strings, (delimited by ‘"’ and ‘_"’), this face is also used for AWK regular expressions (delimited by ‘/’).
This face highlights the following syntactically invalid AWK constructs:
font-lock-warning-face. This is most noticeable when typing in a new string/regular expression into a buffer, when the warning-face serves as a continual reminder to terminate the construct.
AWK mode fontifies unterminated strings/regular expressions differently from other modes: Only the text up to the end of the line is fontified as a string (escaped newlines being handled correctly), rather than the text up to the next string quote.