zgrep(1): suppress the prefixing of filename on output when only
one file is specified to match the grep(1)'s output.

fferentiate zegrep and zfgrep by their basename only, so they can be
invoked with a pathname (ie, /usr/bin/z{e,f}grep).

OK wiz@

2-clause my license.

grep "-H" option (print the filename for each match) always prints
filenames whether "-h" option (suppress filenames when multiple files
are searched) is speficied or not.

Make zgrep "-h" option act

grep "-H" option (print the filename for each match) always prints
filenames whether "-h" option (suppress filenames when multiple files
are searched) is speficied or not.

Make zgrep "-h" option actually works with using "-H" option only
when "-h" is not specified.

show more ...

- fix --.
- fix -e.
- fix patterns starting with -.
- fix "missing argument" message.

use "zcat -fq" not just plain "zcat". this lets zgrep work on non
compressed files (as reported by simonb) as well as not printing
random warnings that zgrep isn't ready to handle.

quote pattern when passing to grep, so that paterns containing
spaces would be handled properly

fixes PR bin/25345 by Arto Selonen

Add RCS Id.

Add a BSD licensed zgrep written by me.
Much nicer than the old one, if I may say so.

Thanks go to atatat for testing and suggestions.