viewfax - display fax files in an X11 window
SYNOPSIS
viewfax [-fnluirv24] [-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 pro
duced 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 com
mands. The left mouse button expands the image by a fac
tor 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.
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).
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 land
scape 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.
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 resolu
tion (3.85 lines/mm) faxes. Each fax line is
duplicated in the displayed image to give approxi
mately 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.
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 (con
sole beep), 'v' for visible bell (flash the win
dow), '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 repo
sitions 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 Han
dleConfigureRequest() in fvwm/events.c to corre
spond 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
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 signif
icant position in a byte. The consensus is to pack
most significant first, but the -r flag is avail
able 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 but
tons (see above) to view expanded portions of the
image.
-2 Assume that raw input files use group 3 two dimen
sional coding.
-4 Assume that raw input files use group 4 coding.
The number of fax lines (-h option) is required in
this case.
SEE ALSO
mgetty (http://alpha.greenie.net/mgetty/) controls
data/fax/voice modems.
hylafax (ftp://sgi.com/sgi/fax) 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.
xli(1) can display a wide variety of image formats,
including g3 faxes. Version 1.15 has difficulty recognis
ing damaged fax files.
faxview.tcl, (ftp://ftp.leo.org/pub/comp/os/unix/network
ing/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.
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).
Man(1) output converted with
man2html