(coreutils.info.gz) Input processing in ptx

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(coreutils.info.gz) Charset selection in ptx

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(coreutils.info.gz) Output formatting in ptx

 
 7.5.3 Word selection and input processing
 -----------------------------------------
 
 '-b FILE'
 '--break-file=FILE'
 
      This option provides an alternative (to '-W') method of describing
      which characters make up words.  It introduces the name of a file
      which contains a list of characters which can_not_ be part of one
      word; this file is called the "Break file".  Any character which is
      not part of the Break file is a word constituent.  If both options
      '-b' and '-W' are specified, then '-W' has precedence and '-b' is
      ignored.
 
      When GNU extensions are enabled, the only way to avoid newline as a
      break character is to write all the break characters in the file
      with no newline at all, not even at the end of the file.  When GNU
      extensions are disabled, spaces, tabs and newlines are always
      considered as break characters even if not included in the Break
      file.
 
 '-i FILE'
 '--ignore-file=FILE'
 
      The file associated with this option contains a list of words which
      will never be taken as keywords in concordance output.  It is
      called the "Ignore file".  The file contains exactly one word in
      each line; the end of line separation of words is not subject to
      the value of the '-S' option.
 
 '-o FILE'
 '--only-file=FILE'
 
      The file associated with this option contains a list of words which
      will be retained in concordance output; any word not mentioned in
      this file is ignored.  The file is called the "Only file".  The
      file contains exactly one word in each line; the end of line
      separation of words is not subject to the value of the '-S' option.
 
      There is no default for the Only file.  When both an Only file and
      an Ignore file are specified, a word is considered a keyword only
      if it is listed in the Only file and not in the Ignore file.
 
 '-r'
 '--references'
 
      On each input line, the leading sequence of non-white space
      characters will be taken to be a reference that has the purpose of
      identifying this input line in the resulting permuted index.  
      Output formatting in ptx, for more information about reference
      production.  Using this option changes the default value for option
      '-S'.
 
      Using this option, the program does not try very hard to remove
      references from contexts in output, but it succeeds in doing so
      _when_ the context ends exactly at the newline.  If option '-r' is
      used with '-S' default value, or when GNU extensions are disabled,
      this condition is always met and references are completely excluded
      from the output contexts.
 
 '-S REGEXP'
 '--sentence-regexp=REGEXP'
 
      This option selects which regular expression will describe the end
      of a line or the end of a sentence.  In fact, this regular
      expression is not the only distinction between end of lines or end
      of sentences, and input line boundaries have no special
      significance outside this option.  By default, when GNU extensions
      are enabled and if '-r' option is not used, end of sentences are
      used.  In this case, this REGEX is imported from GNU Emacs:
 
           [.?!][]\"')}]*\\($\\|\t\\|  \\)[ \t\n]*
 
      Whenever GNU extensions are disabled or if '-r' option is used, end
      of lines are used; in this case, the default REGEXP is just:
 
           \n
 
      Using an empty REGEXP is equivalent to completely disabling end of
      line or end of sentence recognition.  In this case, the whole file
      is considered to be a single big line or sentence.  The user might
      want to disallow all truncation flag generation as well, through
      option '-F ""'.   Syntax of Regular Expressions
      (emacs)Regexps.
 
      When the keywords happen to be near the beginning of the input line
      or sentence, this often creates an unused area at the beginning of
      the output context line; when the keywords happen to be near the
      end of the input line or sentence, this often creates an unused
      area at the end of the output context line.  The program tries to
      fill those unused areas by wrapping around context in them; the
      tail of the input line or sentence is used to fill the unused area
      on the left of the output line; the head of the input line or
      sentence is used to fill the unused area on the right of the output
      line.
 
      As a matter of convenience to the user, many usual backslashed
      escape sequences from the C language are recognized and converted
      to the corresponding characters by 'ptx' itself.
 
 '-W REGEXP'
 '--word-regexp=REGEXP'
 
      This option selects which regular expression will describe each
      keyword.  By default, if GNU extensions are enabled, a word is a
      sequence of letters; the REGEXP used is '\w+'.  When GNU extensions
      are disabled, a word is by default anything which ends with a
      space, a tab or a newline; the REGEXP used is '[^ \t\n]+'.
 
      An empty REGEXP is equivalent to not using this option.  
      Syntax of Regular Expressions (emacs)Regexps.
 
      As a matter of convenience to the user, many usual backslashed
      escape sequences, as found in the C language, are recognized and
      converted to the corresponding characters by 'ptx' itself.
 

Info Catalog

(coreutils.info.gz) Charset selection in ptx

(coreutils.info.gz) ptx invocation

(coreutils.info.gz) Output formatting in ptx