invokes
.I grep
on compressed or gzipped files.
-All options specified are passed directly to
+These
+.I grep
+options will cause
+.I zgrep
+to terminate with an error code:
+.BI (-[drRzZ] | --di* | --exc* | --inc* | --rec* | --nu*) .
+All other options specified are passed directly to
.IR grep .
If no file is specified, then the standard input is decompressed
if necessary and fed to grep.
uses it as the
.I grep
program to be invoked.
+.SH EXIT CODE
+2 - An option that is not supported was specified.
.SH AUTHOR
Charles Levert (charles@comm.polymtl.ca)
.SH "SEE ALSO"