




                            XEQ
                            ===


     XEQ is like the RUN command, except that it will search
one or more directories to find the program you wish to run,
and then chain to that program.   You  may  tell  XEQ  which
directories  to search;  once you have done so, you need not
do it ever again  unless  you  wish  to  change  the  search
directories.   For example, if LB:[100,100] was in my search
path, I would only have to type:

          XEQ PROGRAM

to run LB:[100,100]PROGRAM, even if my default directory was
not LB:[100,100].

     XEQ is also able to pass a command line to the  program
it invokes.  This feature is very useful for users who don't
have the privilege to install tasks, as it  allows  them  to
pass  command lines to their programs from the terminal, or,
most importantly, when the program is executing in a command
file.   Also,  pool space is saved by XEQing programs rather
than installing them.  Uninstalled programs can be stored on
a common task UIC and XEQ'ed when needed provided the UIC is
in your search path.

     XEQ's list of search directories is maintained for each
user  in an installed global common area, XEQCOM.  Currently
there is room for up to 256 users and 380 search directories
in  XEQCOM,  which  is about 8K words long.  The common area
may be enlarged  or  decreased  by  modifying  the  symbolic
parameters in XEQCOM.COM.

     XEQ needs to be able to find out who is running XEQ  to
look  up  the  correct  search  path.  A program, WHOIST, is
included on  this  directory  which  is  mapped  to  IASCOM.
WHOIST  waits  in  a  swapable  stop  state  until it gets a
request for a  user's  name  from  XEQ  through  the  WHOZON
subroutine.

     The three parts  of  XEQ  (XEQ  itself,  XEQCOM  global
common,  and  .WHO.) may all be built by saying @BUILD.  You
will probably want to move XEQ and  WHOIST  to  your  system
task  directory  and XEQCOM to your shared library directory
after building them.

     A test program, ECHO, is built by  the  BUILD  file  to
test XEQ.  ECHO echoes command lines.  In order to receive a
command line from XEQ, a program such as ECHO must be linked
with a routine, RECCML, which is included on this directory.
RECCML's calling sequence is like the calling  sequence  for
GETMCR.   However ECHO illustrates the use of a more general


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routine, GCMD, which attempts to get a  command  line  first
from  MCR  using  GETMCR, then, failing that, from XEQ using
RECCML,  and  failing  that,  from  the  terminal,  using  a
user-specified prompt.  Thus programs which use GCMD can get
their command lines from MCR if they are installed, as  well
as from XEQ or the terminal.  You should look at ECHO.RAT if
you want to use  GCMD.   GCMD  is  located  in  the  support
library, and it's source is in GETARG.RAT.

     The file XEQ.HLP is a user help file which should go in
your  system  help  file.   It explains how to tell XEQ your
search path.  One command is not described in XEQ.HLP;  this
is  the /PEEK command, which causes XEQ to print the name of
each user, his/her search path, and the index of  that  user
in  XEQCOM.   The  output  from /PEEK may be redirected to a
file if FILE is specified after /PEEK, for instance:

          XEQ/PEEK PATH.LST

XEQ is IAS specific.




To build XEQ, do

@BUILD


Documentation is in the file "XEQ.HLP".  Note that users  of
XEQ must have the privilege to chain to another task.  


Send comments, problems, etc.  to:

       William Wood
       Institute For Cancer Research
       7701 Burholme Ave.
       Philadelphia, PA. 19111
       (215) 728 2760



