NAME

       xlito - Append/Delete/Show a Trailing Option string in a file.  (XLoadImageTrailingOptions)

SYNOPSIS

       xlito [option] [string] files ...

DESCRIPTION

       xlito  (XLoadImageTrailingOptions)  is  a  utility that provides a file format independent way of marking
       image files with the appropriate options to display correctly.  It does this by appending to  a  file,  a
       string specified by the user. The string is marked with some magic numbers so that it can be extracted by
       a program that knows what to look for. Since almost all image files have some  sort  of  image  dimension
       information  in  the  file, the programs that load or manipulate these files generally do not look beyond
       the point at which they have read the complete image, so trailing information is  safely  be  hidden.  If
       appending this information causes trouble with other utilities, it can simply be deleted.

       Appropriate  version of xloadimage (ie. xli 1.00) will recognise these trailing options at the end of the
       image files, and will treat the embedded string as if it were a sequence of command line  Image  Options.
       Any  Global  Options  will  be ignored, and unlike command line image Options, Trailing Options are never
       propagated to other images.

       Old versions of xloadimage (3.01 or less) can be made forward compatible by using the -x option  to  pull
       the  trailing  options  out of the image files, and put them on the command line where xloadimage can see
       them.

OPTIONS

       The default behavior is to display the trailing option strings (if any) of  the  files  on  the  argument
       line.  The following options change the behavior of xlito:

       -c option_string file_name ...
               This  adds or changes the embedded string to option_string.  The string will have to be quoted if
               it is composed of more than one word.

       -d file_name ...
               Delete any embedded trailing option strings in the given files.

       -x file_name ...
               Process the files and create a command line string suitable  for  use  by  xloadimage.  Arguments
               starting  with  - are echoed, arguments not starting with - are treated as files and any trailing
               options strings are echoed followed by the file name. The  xloadimage  option  -name  is  treated
               correctly.

EXAMPLES

       If fred.gif has the wrong aspect ratio, then it might need viewing with the xloadimage options:

            xloadimage -yzoom 130 fred.gif

       This option can then be appended to the file by:

            xlito -c "-yzoom 130" fred.gif

       and  from  then  on  some new versions of xloadimage will get the appropriate options from the image file
       itself. Old versions of xloadimage can be made to work by using:

            xloadimage `xlito -x fred.gif`

       This can be made transparent by using a script containing something like:

            xloadimage `xlito -x $∗`

       The script could be called xli for instance.

       The options can be deleted with:

            xlito -d fred.gif

AUTHOR

       Graeme Gill
       Labtam Australia
       graeme@labtam.oz.au

MAINTAINER

       smar@reptiles.org

COMPATIBILITY WITH IMAGE FILES

       Some image files are actually ascii files that are used  in  other  contexts.   X  Bitmap  files  are  an
       example.  They  are  formatted as 'C' style #defines and an initialised array of characters, so that they
       can be included in 'C' source code.  Adding trailing options would therefore  render  the  file  unusable
       with a compiler, since it will get a syntax error on the railing option string and the magic numbers. The
       solution to this is that xlito will ignore a certain amount (a few  hundred  bytes)  after  the  trailing
       options,  and  uses a padding of 20 bytes before the trailing options. These two areas will be maintained
       when changing an existing trailing option. In the case of an X bitmap then, the solution is to  edit  the
       file and place the embedded string in some 'C' comments:

       eg: say the file starts as:
       #define tt_width 4
       #define tt_height 4
       static char tt_bits[] = {
          0x08, 0x02, 0x04, 0x01};

       and you add a trailing options:
       #define tt_width 4
       #define tt_height 4
       static char tt_bits[] = {
          0x08, 0x02, 0x04, 0x01};
       01234567890123456789XXX xloadimage trailing options XXX0007"-smooth"0007XXX
       xloadimage trailing options XXX

       Then the trailing options can be commented out:
       #define tt_width 4
       #define tt_height 4
       static char tt_bits[] = {
          0x08, 0x02, 0x04, 0x01};
       /∗234567890123456789XXX xloadimage trailing options XXX0007"-smooth"0007XXX
       xloadimage trailing options XXX ∗/

BUGS

       xlito  doesn't  cope  with compressed files. A files will need uncompressing, the options added, and then
       compressing again.

                                                   7 Jul 1993                                           XLITO(1)