Info Catalog grep: Generic Program Information grep: Command-line Options grep: General Output Control

grep: Matching Control

 
 2.1.2 Matching Control
 ----------------------
 
 ‘-e PATTERN’
 ‘--regexp=PATTERN’
      Use PATTERN as the pattern.  If this option is used multiple times
      or is combined with the ‘-f’ (‘--file’) option, search for all
      patterns given.  (‘-e’ is specified by POSIX.)
 
 ‘-f FILE’
 ‘--file=FILE’
      Obtain patterns from FILE, one per line.  If this option is used
      multiple times or is combined with the ‘-e’ (‘--regexp’) option,
      search for all patterns given.  The empty file contains zero
      patterns, and therefore matches nothing.  (‘-f’ is specified by
      POSIX.)
 
 ‘-i’
 ‘-y’
 ‘--ignore-case’
      Ignore case distinctions, so that characters that differ only in
      case match each other.  Although this is straightforward when
      letters differ in case only via lowercase-uppercase pairs, the
      behavior is unspecified in other situations.  For example,
      uppercase “S” has an unusual lowercase counterpart “ſ” (Unicode
      character U+017F, LATIN SMALL LETTER LONG S) in many locales, and
      it is unspecified whether this unusual character matches “S” or “s”
      even though uppercasing it yields “S”.  Another example: the
      lowercase German letter “ß” (U+00DF, LATIN SMALL LETTER SHARP S) is
      normally capitalized as the two-character string “SS” but it does
      not match “SS”, and it might not match the uppercase letter “ẞ”
      (U+1E9E, LATIN CAPITAL LETTER SHARP S) even though lowercasing the
      latter yields the former.
 
      ‘-y’ is an obsolete synonym that is provided for compatibility.
      (‘-i’ is specified by POSIX.)
 
 ‘-v’
 ‘--invert-match’
      Invert the sense of matching, to select non-matching lines.  (‘-v’
      is specified by POSIX.)
 
 ‘-w’
 ‘--word-regexp’
      Select only those lines containing matches that form whole words.
      The test is that the matching substring must either be at the
      beginning of the line, or preceded by a non-word constituent
      character.  Similarly, it must be either at the end of the line or
      followed by a non-word constituent character.  Word-constituent
      characters are letters, digits, and the underscore.  This option
      has no effect if ‘-x’ is also specified.
 
 ‘-x’
 ‘--line-regexp’
      Select only those matches that exactly match the whole line.  For a
      regular expression pattern, this is like parenthesizing the pattern
      and then surrounding it with ‘^’ and ‘$’.  (‘-x’ is specified by
      POSIX.)
 

Info Catalog grep: Generic Program Information grep: Command-line Options grep: General Output Control