4.10 Directories On The Command Line

According to the POSIX standard, files named on the awk command line must be text files. It is a fatal error if they are not. Most versions of awk treat a directory on the command line as a fatal error.

By default, gawk produces a warning for a directory on the command line, but otherwise ignores it. If either of the ‘--posix’ or ‘--traditional’ options is given, then gawk reverts to treating a directory on the command line as a fatal error.