While the filter interface is compatible with System V interface scripts, CUPS does not support System V interface scripts.
.SH NOTES
CUPS filters are not meant to be run directly by the user.
-Aside from the legacy System V interface issues (\fIargv[0]\fR is the printer name), CUPS filters also expect specific environment variables and file descriptors, and typically run in a user session that (on OS X) has additional restrictions that affect how it runs.
+Aside from the legacy System V interface issues (\fIargv[0]\fR is the printer name), CUPS filters also expect specific environment variables and file descriptors, and typically run in a user session that (on macOS) has additional restrictions that affect how it runs.
Unless you are a developer and know what you are doing, please do not run filters directly.
Instead, use the
.BR cupsfilter (8)