2.0; chpat (change_pattern), revision 2.0, 81/07/01.
CHPAT (CHANGE_PATTERN) -- Replace pattern in text file.
usage: CHPAT [-A|-X] [-L] [-O] [-OUT [pathname]] [pathname... -P]
         [from_pattern | [pat...] from_pattern to_expr]


FORMAT

  CHPAT [options] [pathname ... -P] [from_pattern | pat ...]
        from_pattern [to_expression]


  CHPAT copies every line from its input files to its output files,
  globally substituting the text replacement pattern "to_expr" for
  each occurrence of "fr_pat" in those lines which match according
  to the "pat" arguments and the options flags.

  Refer to the help files of the ED (EDIT), FPAT (FIND_PATTERN), and
  EDSTR (EDIT_STREAM) commands for related information.

ARGUMENTS

  pathname
  (optional)       Specify name of file to be searched.  Multiple pathnames
                   and wildcarding are permitted.  If this argument is present,
                   it must be followed by "-P" to separate the pathname(s)
                   from the search patterns on the command line.
                   Default if omitted: search standard input.
  from_pattern
  (required)       Specify target text string (a regular expression) for
                   substitution or deletion.  If the string includes the
                   characters % $ [ ] { } ! * or any other Shell special
                   characters, enclose it in quotes to avoid unpredictable
                   results.

  to_expression
  (optional)       Specify replacement string.  If no replacement is specified,
                   the 'from_pattern' string will be deleted. If regular
                   expressions defining a range of text ('pat' argument) are
                   present, you must use a literally null 'to_expression' ("")
                   to delete 'from_pattern'.

  pat
  (optional)       Specify range of text for which the substitution is to
                   apply, in the form of a regular expression . Multiple
                   expressions separated by blanks are permitted.  Unless
                   modified by options, any line of text matching any pattern
                   is replaced and all lines, changed or not, are written to
                   output.
                   Default if omitted: use 'from_pattern' to select matching
                                       lines


OPTIONS

  -A               Select only lines that match all of the leading expressions,
                   in any order.

  -X               Select only lines that match none of the leading expressions.

  -O               Write only the selected lines to standard output.  By default,
                   CHPAT writes all lines to output.

  -L               List name(s) of input file(s) on output file(s) as the input
                   file(s) are searched.

  -OUT pathname    Specify name of output file.  Pathname may be derived from
                   the input file name.  If this option is omitted, output is
                   written to standard output.


EXAMPLES

  1. $ chpat foo bar

     changes all occurrences of 'foo' in standard input to  'bar'  and
     writes the results to standard output.

  2. $ chpat '%This' "  *" ' '

     in  lines  starting  with  'This',  it changes all occurrences of
     multiple spaces to a single space.

  3. $ chpat '%This' '%That' "  *" ' '

     like 2., but works  on  lines  starting  with  either  'This' OR
     'That'.

  4. $ chpat -a '%when' 'only$' ';' ':'

     in  lines  that start with 'when' AND end with 'only', change all
     semicolons to colons.

  5. $ chpat -x not none some all

     in lines that do NOT contain either 'not' or 'none',  change  all
     instances of 'some' to 'all'.

  6. $ chpat erase

     delete   (replace   with  nothing)  all  occurences  of  'erase'.
     Exactly the same effect can be obtained with:

     $ chpat erase ''

  7. $ chpat -o other_opts pat... fr_pat to_pat

     is exactly the same as

     $ fpat pat... | chpat other_opts fr_pat to_pat

  8. $ chpat ?*.pas -out =.new -p "if x = y" "if (x = y)"

     will  change  all  occurrences  of  the  string   "if x = y"   to
     "if (x = y)"  in  all  pascal  source  files  (files  ending with
     '.pas') and put the output for, say, 'X.pas' in 'X.pas.new'.

RELATED TOPICS

  More information is available.  Type:

    - HELP PATTERNS
      for details about regular expression syntax and usage.