Provided by: mgetty-viewfax_1.1.36-1.6_amd64 bug

NAME

       viewfax - display fax files in an X11 window

SYNOPSIS

       viewfax  [-fnluirvW24]  [-hheight]  [-wwidth]  [-zzoom]  [-ddisplay]  [-gwxh+x+y] [-bbell]
       [-mmemory] filename...

DESCRIPTION

       viewfax displays one or more fax files in an X11 window.  The input files  may  be  either
       raw,  single-page  faxes received by a fax modem with a program such as mgetty(1), or tiff
       files such as those used by hylafax.  The first  (or  only)  page  of  "PC-Research"-style
       (DigiFAX)  files  produced  by  the  ghostscript  dfaxhigh  or dfaxlow drivers can also be
       displayed.

       Input files using any common fax encoding such as group 3 (1 and 2 dimensional) and  group
       4 can be displayed.

       The  fax  images  are  rendered  at full resolution and then successively scaled down by a
       linear factor of 2 prior to display, until they fit on the screen.   The  display  can  be
       controlled interactively using mouse and keyboard commands.  The left mouse button expands
       the image by a factor of two and the right button reduces it by the same factor.   If  the
       image  is  bigger  than  the available window size, the middle mouse button can be used to
       reposition it within the window.  Hold down the middle button while dragging the image  to
       its new position.

       If  the  mouse  has  a  scroll-wheel it can be used to move an oversized image vertically.
       With the shift key depressed, the wheel scrolls through the pages.   The  shift  sense  is
       inverted if viewfax is started with -W on the command-line.

       Further interaction is controlled by single-key commands:

       h or Help
              displays a page of help information.  Type 'q' to return to the original document.

       p or Prior or PgUP or - or BackSpace
              displays the previous page from the command-line list.

       n or Next or PgDn or + or space
              displays the next page from the command-line list.

       Shift HOME
              displays the first page from the command-line list.

       Shift END
              displays the last page from the command-line list.

       z      zoom in (same as right mouse button).

       Shift Z
              zoom out (same as left mouse button).

       u      turns  the  image  upside  down,  which is useful if the fax was originally fed the
              wrong way into the machine.

       Shift U
              turns this and all following pages upside down.

       l      turns the image through 90 degrees, to view landscape text.

       Shift L
              turns this and all following pages sideways.

       m      produce a left/right mirror image of the page.

       Shift M
              mirror this and all following pages.

       cursor arrows
              reposition the displayed image if it exceeds the window size.

       HOME   repositions so that the top left corner is visible.

       END    makes the bottom right corner visible.

       Print  if the environment variable VIEWFAX_PRINT is defined, the current page is  printed.
              All pages are printed with Shift Print.

       e      if  the environment variable VIEWFAX_EDIT is defined, the current page is passed to
              the editor.  All input files can be edited with Shift e.

       q      terminates the program.

       Shift Q
              terminates the program with non-zero exit status.  Can be used  to  abort  a  shell
              script,  e.g.  when  the user is previewing an outbound fax and decides not to send
              it.

OPTIONS

       viewfax is designed to "do the right thing" when given just a filename.  Special cases can
       be  handled  with  the  following  options.   (Note that tiff-files contain a header which
       overrides the -f, -n, -h, -w, -l, -m, and -u flags.)

       -f     indicates that raw input files are fine resolution (7.7 lines/mm) faxes.   This  is
              the default unless the filename begins with "fn".  Tiff and "PC-Research" (DigiFAX)
              files are self-specifying.

       -n     indicates that raw input files are normal resolution (3.85 lines/mm)  faxes.   Each
              fax  line is duplicated in the displayed image to give approximately equal vertical
              and horizontal scales.

       -hheight
              specifies the number of fax lines.  If this option is missing, viewfax  counts  the
              number of lines in the input file.

       -wwidth
              specifies the number of pixels in each scan-line.  The default value is 1728.

       -l     display in landscape mode.

       -u     turn the image upside down.

       -i     invert pixels (black/white).

       -b     preferred  warning style: 'a' for audible bell (console beep), 'v' for visible bell
              (flash the window), 'n' for neither.  'v' is the default.

       -d or -display
              use specified X server

       -g or -geometry
              the preferred size and position of the window, specified as widthxheight+x+y.  If a
              position  is  given  (x and y values), viewfax asks the window manager to place the
              window there.  The initial size  of  the  window  is  constrained  to  be  at  most
              widthxheight.

              If  the  window  is  subsequently  resized  due  to the user zooming in or out, the
              geometry is taken as a constraint on the screen area which may be used by viewfax.

              If you do not supply a geometry value, everything works fine  with  ICCCM-compliant
              window  managers like olwm, mwm, twm, and tvtwm.  When fully zoomed out the viewfax
              window will occupy the entire screen.

              Users of fvwm will notice that the title bar and left border are moved  off  screen
              when  viewfax  repositions  the  window to (0,0).  A workaround is to use -geometry
              +5+23 when using fvwm.  The proper fix would be for someone to update  the  routine
              HandleConfigureRequest()   in   fvwm/events.c   to   correspond   to  the  code  in
              twm/events.c.

       -mmemory limit
              each page is kept in memory after being fetched and expanded, which saves  time  if
              the  user returns to it in the same session.  To prevent viewfax from using all the
              available swap space, a limit is placed on the total size of cached  images.   This
              defaults  to  4  MBytes,  enough for about 6 typical pages.  If the memory limit is
              exceeded, old images are discarded and must be  reloaded  from  disk  if  the  user
              returns  to  them.   The  operation of this mechanism is transparent apart from the
              occasional delays due to reloading.  The value specified on the command line can be
              suffixed k or m for kilo- or megabytes.

       -r     the  bit  order  of the bytes in the input file is reversed.  The fax specification
              deals only with serial data  transmission.   Modem  manufacturers  have  to  decide
              whether  the  first  bit  received  should be placed in the most significant or the
              least significant position in a byte.  The consensus is to  pack  most  significant
              first, but the -r flag is available to deal with the opposite order.

       -v     produce some informative messages (verbose mode).

       -zzoom specifies  an  initial  zoom  factor.  A full-scale fax will usually not fit on the
              screen.  If the -z option is not specified, viewfax scales the image by a power  of
              2 such that it is fully visible at a reduced size.  The user can then use the mouse
              buttons (see above) to view expanded portions of the image.

       -2     Assume that raw input files use group 3 two dimensional coding.

       -4     Assume that raw input files use group 4  coding.   The  number  of  fax  lines  (-h
              option) is required in this case.

ENVIRONMENT

       VIEWFAX_PRINT
              Defines a command that will print one or more fax pages.

       VIEWFAX_EDIT
              Defines a command that will calls an editor on one or more fax pages.

       These  two variables are optional.  If a variable is undefined, the corresponding keyboard
       command is ignored.  If the variable is defined, it should contain the name of  a  command
       or  executable  script  that  performs the desired function.  The command should process a
       single page if called with a -p page-number argument.  Alternatively,  if  can  be  called
       with just a list of filenames, meaning that all pages should be processed.

       Here  is  an  oversimplified  example  of  a print command.  Note that it assumes that the
       format is tiff and will fail when handed a raw fax file.
         VIEWFAX_PRINT=printfax

         /usr/local/bin/printfax:
         #!/bin/sh
         case "$1" in
         -p) shift
             dopt=`expr $1 - 1`
             shift
             tiff2ps -d ${dopt} -2 -h 11.69 -w 8.27 "$1" | lp
             ;;
         *)  tiff2ps -2 -h 11.69 -w 8.27 "$*" | lp
             ;;
         esac

SEE ALSO

       mgetty (http://alpha.greenie.net/mgetty/) controls data/fax/voice modems.

       hylafax (http://www.hylafax.org/) is a full-function fax client/server system.

       g3topbm(1) and xv(1) can be used in a pipeline to view faxes.  This will usually be slower
       than  using viewfax, but xv has many capabilities for manipulating the image and saving it
       in other formats.

       faxview.tcl,    (ftp://ftp.leo.org/pub/comp/os/unix/networking/mgetty/faxview.tcl.gz)    a
       simple dialog for viewing FAX messages by Ralph Schleicher (rs@purple.in-ulm.de).  This is
       a useful tool which provides a file menu from which incoming faxes  can  be  selected  for
       display with viewfax.

       CCITT  (now  ITU)  Recommendation  T.4, Standardization of Group 3 Facsimile Apparatus for
       Document Transmission.

       CCITT (now ITU) Recommendation T.6, Facsimile Coding Schemes and Coding Control  Functions
       for Group 4 Facsimile Apparatus.

BUGS

       The user interface does not comply with any known style guide.
       The  help  text looks moth-eaten because it is encoded as a fax.  This avoids dealing with
       X11 fonts.
       The program does not refer to the X resources database.

AUTHOR

       Frank D. Cringle (fdc@cliwe.ping.de).