TOGEOMVIEW(1gv) 														   TOGEOMVIEW(1gv)

NAME

       togeomview - send commands or OOGL objects to geomview

SYNOPSIS

       togeomview [-c] [-g]  [pipename	[program args ...]]

DESCRIPTION

       togeomview  sends a stream of geomview commands, or OOGL-format geometric data, to a cooperating copy of geomview.  If geomview is not run-
       ning, it is automatically started.  ('geomview' must be on the $PATH of the user running 'togeomview' in order for this to work.)

       Typical usage is:
	    someprogram | togeomview	(to send commands) or
	    someprogram-generating-OOGL-data | togeomview -g  (to send geometry)
       i.e. a program pipes geometric data into ``togeomview''; the data is displayed by a copy of geomview run with the  -M  option  and  a  name
       matching the one given to togeomview.

       Togeomview  uses  a  named  pipe  in  the directory /tmp/geomview to communicate with geomview.	If unspecified, the pipe's default name is
       "OOGL".	When sending geometry (-g), a geomview object with the same name as the pipe appears in geomview's object browser.

       By default, when no suitable copy of geomview is running, togeomview invokes "geomview" with arguments  specifying  the	appropriate  named
       pipe.  A different command may be specified as in:

	    togeomview	OOGL  gv -wpos 300x300 -c my_startup_script

       which  communicates  through a pipe named OOGL, and (if necessary) invokes the given gv command.  The pipe name is required if a command is
       specified.

       After togeomview has created it, the named pipe may be written as an ordinary file.  For example, one could use

	    togeomview pipename < /dev/null

       to invoke a listening copy of geomview, and then run a program which simply wrote to /tmp/geomview/pipename.

FILES

       /tmp/geomview

BUGS

       The pipe-based communications scheme imposes several restrictions.

       If no copy of geomview is reading from the pipe, or if geomview gets far enough behind, a program writing data to  ``togeomview''  will	be
       forced to block after sending a few kilobytes.

       Because of the buffering in the pipe, the sender may be substantially ahead of the geomview display.

       If  geomview  exits,  the sending program receives a write-on-broken-pipe (SIGPIPE) signal, which will kill it unless measures are taken to
       catch or ignore that signal.

       Only one copy of geomview can read from a given pipe at a time.	If a second copy attempts to read from it, both will probably fail.   It's
       fine to have multiple copies of geomview reading from different pipes.

       Note  that  togeomview  will  invoke  geomview if no extant copy is listening to the relevant pipe; it can't connect to an existing copy of
       geomview started by other means.

SEE ALSO

       geomview(1), oogl(5)

Geometry Center 						    21 May 1993 						   TOGEOMVIEW(1gv)