README

usage: ogrep -- [OPTIONS] PATTERN [FILE...]
       ogrep -- [OPTIONS] [-e PATTERN | -f FILE] [FILE...]

The '--' is required, so AWK itself doesn't read the options

Searches the named input FILEs (or standard input if no files are named, or
if a single hyphen (-) is given as a filename) for lines matching the given
PATTERN. Prints only the matching portions of each line, with each portion on a
separate output line.  PATTERNs may be any regular expression valid in AWK.

 Options:
  -h, --help            Display this help and exit
  -F, --fixed-strings   Interpret PATTERN as a list of fixed strings, separated
                        by newlines
  -e, --regex PATTERN   Use PATTERN as the pattern. This can be used to specify
                        multiple search patterns, or to protect a pattern
                        beginning with a hyphen (-)
  -f, --file FILE       Use FILE as a list of patterns, one per line. may be
                        given multiple times, all files will be read
  -i, --ignore-case     Ignore case distinctions in both the PATTERN and the
                        input files.
  -c, --count           Suppress normal output; instead print a count of
                        matching strings for each input file
  -W, --with-filename   Print the file name for each match. this is the default
                        when there is more than one input file
  -w, --no-filename     Do not print the file name for each match. this is the
                        default when there is only one input file, or ogrep is
                        only reading stdin
  -n, --line-number     Prefix each line of output with the 1-based line number
                        within its input file.
  -Z, --null            Separate each output line with a NUL byte