OS/2 Professional/OS2PRO194.ISO/os2/prgramer/unix/doc/wdiff.man

Text File | 1993-06-13 | 12.4 KB | 397 lines

WDIFF(1)                                                 WDIFF(1)


NAME
       wdiff - display word differences between text files


SYNOPSIS
       wdiff [ option ...  ] old_file new_file


COPYRIGHT
       Copyright (C) 1992 by the Free Software Foundation, Inc.


DESCRIPTION
       wdiff  compares  two  files, finding which words have been
       deleted or added to old_file to get new_file.  A  word  is
       anything  between whitespace.  The output is collected and
       used to produce an annotated copy of new_file on  standard
       output.  Suitable  annotations  produce  a nice display of
       word differences between the original files.

       wdiff will exit with a status of 0 if no differences  were
       found,  a  status of 1 if any differences were found, or a
       status of 2 for any error.

       Usually underlining is used to mark  deleted  text,  while
       bold or reverse video is used to mark inserted text; these
       defaults may  be  over-ridden  by  command  line  options.
       deleted  text  refers  to text in old_file which is not in
       new_file, while inserted text refers to text  on  new_file
       which is not in old_file.


OPTIONS
       --help Has the same effect as -h.

       -h     Print  an  informative  help message describing the
              options.

       --version
              Has the same effect as -v.

       -v     Print the version number of wdiff on  the  standard
              error output.

       --no-deleted
              Has the same effect as -1.

       -1     Avoid  producing  deleted  words  on the output. If
              neither -1 or -2 is selected,  the  original  right
              margin may be exceeded for some lines.

       --no-inserted
              Has the same effect as 2.




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WDIFF(1)                                                 WDIFF(1)


       -2     Avoid  producing  inserted  words on the output. If
              neither -1 or -2 is selected,  the  original  right
              margin may be exceeded for some lines.

       --no-common
              Has the same effect as -3.

       -3     Avoid  producing  common words on the output.  When
              this option  is  not  selected,  common  words  and
              whitespace are taken from new_file.  When selected,
              differences are separated from one another by lines
              of dashes.  Moreover, if this option is selected at
              the same time as -1 or -2, then none of the  output
              will  have any emphasis - i.e. no bold or underlin-
              ing.  Finally, if this option is not selected,  but
              both  -1  and -2 are, then sections of common words
              between  differences  are  separated  by  lines  of
              dashes.


       --statistics
              Has the same effect as -s.

       -s     On  completion,  for each file, the total number of
              words, the  number  of  common  words  between  the
              files,  the number of words deleted or inserted and
              the number of words that have changed is output. (A
              changed  word  is  one that has been replaced or is
              part of a replacement.)  Except for the total  num-
              ber  of words, all of the numbers are followed by a
              percentage relative to the total number of words in
              the file.


       --auto-pager
              Has the same effect as -a.

       -a     A  pager is interposed whenever the wdiff output is
              directed to  the  user's  terminal.   Without  this
              option,  no  pager will be called; the user is then
              responsible for explicitly piping wdiff output into
              a pager if required.

              The  pager  is  selected  by the value of the PAGER
              environment variable when wdiff is run.   If  PAGER
              is  not  defined at run time, then a default pager,
              selected  at  installation  time,  will   be   used
              instead.   A defined but empty value of PAGER means
              no pager at all.

              When a pager is interposed through the use of  this
              option,  one  of  the  options  -l  or  -t  is also
              selected, depending on whether  the  string  "less"
              appears in the pager's name or not.



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WDIFF(1)                                                 WDIFF(1)


              It  is often useful to define wdiff as an alias for
              wdiff -a.  However, this "hides" the  normal  wdiff
              behaviour.  The  default  behaviour may be restored
              simply by piping the output from wdiff through cat.
              This dissociates the output from the user terminal.


       --printer
              Has the same effect as -p.

       -p     Use over-striking to emphasize parts of the output.
              Each character of the deleted text is underlined by
              writing an underscore _ first, then a backspace and
              then  the  letter to be underlined.  Each character
              of the inserted text is emboldened  by  writing  it
              twice, with a backspace in between.  This option is
              not selected by default.


       --less-mode
              Has the same effect as -l.

       -l     Use over-striking to  emphasize  parts  of  output.
              This  option  works  as  option  -p, but also over-
              strikes whitespace associated with  inserted  text.
              less  shows  such  whitespace  using reverse video.
              This option is not selected by  default.   However,
              it   is  automatically  turned  on  whenever  wdiff
              launches less.  (See option -a.)

              This option is commonly used  in  conjunction  with
              less:

              wdiff -l old_file new_file | less


       --terminal
              Has the same effect as -t.

       -t     Force  the production of termcap strings for empha-
              sising parts of output, even if the standard output
              is  not associated with a terminal.  The TERM envi-
              ronment variable must contain the name of  a  valid
              termcap entry. If the terminal description permits,
              underlining is used for marking deleted text, while
              bold  or reverse video is used for marking inserted
              text.  This option  is  not  selected  by  default.
              However,  it  is  automatically  turned on whenever
              wdiff launches a pager, and it is  known  that  the
              pager is not less.  (See option -a.)

              This  option  is commonly used when wdiff output is
              not redirected, but sent  directly  to  the  user's
              terminal, as in:



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WDIFF(1)                                                 WDIFF(1)


              wdiff -t old_file new_file

              A  common kludge uses wdiff together with the pager
              more, as in:

              wdiff -t old_file new_file | more


              However, some versions of more use termcap emphasis
              for their own purposes, so strange interactions are
              possible.


       --start-delete argument
              Has the same effect as -w.

       -w argument
              Use argument as the "start  delete"  string.   This
              string  will  be  output prior to every sequence of
              deleted text, to mark where it starts.  By default,
              no  start  delete string is used unless there is no
              other  means  of  distinguishing  where  such  text
              starts;  in  this  case  the  default  start delete
              string is [-.


       --end-delete argument
              Has the same effect as -x.

       -x argument
              Use argument as  the  "end  delete"  string.   This
              string  will  be  output  after  every  sequence of
              deleted text, to mark where it ends.   By  default,
              no  end  delete  string  is used unless there is no
              other means of distinguishing where such text ends;
              in this case the default end delete string is -].


       --start-insert argument
              Has the same effect as -y.

       -y argument
              Use  argument  as  the "start insert" string.  This
              string will be output  prior  to  any  sequence  of
              inserted   text,  to  mark  where  it  starts.   By
              default, no start  insert  string  is  used  unless
              there  is  no  other  means of distinguishing where
              such text starts; in this case  the  default  start
              insert string is {+.


       --end-insert argument
              Has the same effect as -z.




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WDIFF(1)                                                 WDIFF(1)


       -z argument
              Use  argument  as  the  "end  insert" string.  This
              string  will  be  output  after  any  sequence   of
              inserted  text, to mark where it ends.  By default,
              no end insert string is used  unless  there  is  no
              other means of distinguishing where such text ends;
              in this case the default end insert string is +}.


       --avoid-wraps
              Has the same effect as -n.

       -n     Avoid  spanning  the  end  of  line  while  showing
              deleted  or  inserted text.  Any single fragment of
              deleted or inserted text spanning many  lines  will
              be  considered  as  being  made  up of many smaller
              fragments not containing  a  newline.   So  deleted
              text,  for  example, will have an end delete string
              at the end of each line, just before the new  line,
              and  a  start delete string at the beginning of the
              next line.  A long paragraph of inserted text  will
              have  each  line bracketed between start insert and
              end insert strings.  This behaviour is not selected
              by default.



       Note  that  options  -p,  -t, and -[wxyz] are not mutually
       exclusive. If you use a  combination  of  them,  you  will
       merely  accumulate  the  effect  of  each.  Option -l is a
       variant of option -p.


EXAMPLES
       The following command produces a copy of new_file, shifted
       right  one space to accommodate change bars since the last
       revision, ignoring those changes coming  only  from  para-
       graph  refilling.   Any line with new or changed text will
       get a | in column 1. However, deleted text  is  not  shown
       nor marked.

       wdiff  -1n  old_file  new_file  |  sed  -e 's/^/ /;/{+/s/^
       /|/;s/{+//g;s/+}//g'



BUGS
       If you find a bug in wdiff, please send electronic mail to
       [e-mail].    Include  the  version  number,
       which you can find by running wdiff --version.  Include in
       your message sufficient input to reproduce the problem and
       also, the output you expected.

       wdiff currently calls diff.  wdiff would  be  quicker  and



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WDIFF(1)                                                 WDIFF(1)


       cleaner  to implement if it were part of the diff suite of
       programs.

       Here are some (un-processed) suggestions:

       -      Make an MS-DOS port.

       -      Select by options exactly what is whitespace.

       -      Have a wpatch program.  Hard to see a good  way  of
              doing this.



IDENTIFICATION
       Author: Francois Pinard, [e-mail]
       Manual Page: Colin M. Brough, [e-mail]
       Revision Number: 0.4; Release Date: 1992/12/21.


SEE ALSO
       diff(1), less(1), cat(1), more(1), termcap(3).



































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