grep searches a file for a given pattern.  Execute by
	 grep [flags] regular_expression file_list

Flags are single characters preceeded by '-':
   -c	    Only a count of matching lines is printed
   -f	    Print file name for matching lines switch, see below
   -n	    Each line is preceeded by its line number
   -v	    Only print non-matching lines

The file_list is a list of files.
If no files are given, input comes from the terminal --
  there is no prompting.
The file name is normally printed if there is a file given.
The -f flag reverses this action (print name no file, not if more).

The regular_expression defines the pattern to search for.  Upper- and
lower-case are always ignored.  Blank lines never match.
x	An ordinary character (not mentioned below) matches that character.
'\'	The backslash quotes any character.  "\$" matches a dollar-sign.
'^'	A circumflex at the beginning of an expression matches the
	  beginning of a line.
'$'	A dollar-sign at the end of an expression matches the end of
	  a line.
'.'	A period matches any character except "new-line".
':a'	A colon matches a class of characters described by the following
':d'	  character.  ":a" matches any alphabetic, ":d" matches digits,
':n'	  ":n" matches alphanumerics, ": " matches spaces, tabs, and
':~'	  other control characters, such as new-line.
'*'	An expression followed by an asterisk matches zero or more
	  occurrances of that expression: "fo*" matches "f", "fo"
	  "foo", etc.
'+'	An expression followed by a plus sign matches one or more
	  occurrances of that expression: "fo+" matches "fo", etc.
'-'	An expression followed by a minus sign optionally matches
	  the expression.
'[]'	A string enclosed in square brackets matches any character in
	  that string, but no others.  If the first character in the
	  string is a circumflex, the expression matches any character
	  except "new-line" and the characters in the string.  For
	  example, "[xyz]" matches "xx" and "zyx", while "[^xyz]"
	  matches "abc" but not "axb".  A range of characters may be
	  specified by two characters separated by "-".  Note that,
	  [a-z] matches alphabetics, while [z-a] never matches.

The concatenation of regular expressions is a regular expression.

[These inadequate instructions are reproduced exactly as the author
intended. Use Control-S, then Control-C to stop program. Use ":~"
to make spaces.]

