Provided by: gzip_1.6-5ubuntu2_amd64
zgrep - search possibly compressed files for a regular expression
zgrep [ grep_options ] [ -e ] pattern filename...
Zgrep invokes grep on compressed or gzipped files. These grep options will cause zgrep to terminate with an error code: (-[drRzZ]|--di*|--exc*|--inc*|--rec*|--nu*). All other options specified are passed directly to grep. If no file is specified, then the standard input is decompressed if necessary and fed to grep. Otherwise the given files are uncompressed if necessary and fed to grep. If the GREP environment variable is set, zgrep uses it as the grep program to be invoked.
2 - An option that is not supported was specified.
Charles Levert (firstname.lastname@example.org)