viewfax

viewfax(1)                      Local commands                      viewfax(1)



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).



FrankĀ“s Hacks                  14 November 2004                     viewfax(1)