1TOGEOMVIEW(1gv)                                                TOGEOMVIEW(1gv)
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NAME

6       togeomview - send commands or OOGL objects to geomview
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SYNOPSIS

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

12       togeomview  sends a stream of geomview commands, or OOGL-format geomet‐
13       ric data, to a cooperating copy of geomview.  If geomview is  not  run‐
14       ning, it is automatically started.  ('geomview' must be on the $PATH of
15       the user running 'togeomview' in order for this to work.)
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17       Typical usage is:
18            someprogram | togeomview    (to send commands) or
19            someprogram-generating-OOGL-data | togeomview -g  (to send geometry)
20       i.e. a program pipes geometric data into ``togeomview'';  the  data  is
21       displayed  by  a  copy  of  geomview  run with the -M option and a name
22       matching the one given to togeomview.
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24       Togeomview uses a named pipe in the directory /tmp/geomview to communi‐
25       cate with geomview.  If unspecified, the pipe's default name is "OOGL".
26       When sending geometry (-g), a geomview object with the same name as the
27       pipe appears in geomview's object browser.
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29       By  default,  when  no suitable copy of geomview is running, togeomview
30       invokes "geomview" with  arguments  specifying  the  appropriate  named
31       pipe.  A different command may be specified as in:
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33            togeomview  OOGL  gv -wpos 300x300 -c my_startup_script
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35       which  communicates  through  a  pipe  named  OOGL,  and (if necessary)
36       invokes the given gv command.  The pipe name is required if  a  command
37       is specified.
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39       After  togeomview  has  created it, the named pipe may be written as an
40       ordinary file.  For example, one could use
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42            togeomview pipename < /dev/null
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44       to invoke a listening copy of geomview, and then run  a  program  which
45       simply wrote to /tmp/geomview/pipename.
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FILES

48       /tmp/geomview
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BUGS

51       The pipe-based communications scheme imposes several restrictions.
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53       If  no  copy  of geomview is reading from the pipe, or if geomview gets
54       far enough behind, a program writing data  to  ``togeomview''  will  be
55       forced to block after sending a few kilobytes.
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57       Because  of  the buffering in the pipe, the sender may be substantially
58       ahead of the geomview display.
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60       If geomview exits, the sending program receives a  write-on-broken-pipe
61       (SIGPIPE) signal, which will kill it unless measures are taken to catch
62       or ignore that signal.
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64       Only one copy of geomview can read from a given pipe at a time.   If  a
65       second  copy  attempts  to read from it, both will probably fail.  It's
66       fine to have multiple copies of geomview reading from different pipes.
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68       Note that togeomview will invoke geomview if no extant copy is  listen‐
69       ing  to  the  relevant  pipe;  it  can't connect to an existing copy of
70       geomview started by other means.
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SEE ALSO

73       geomview(1), oogl(5)
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77Geometry Center                   21 May 1993                  TOGEOMVIEW(1gv)