Redirecting I/O
Description
Application programs often call routines that display data on standard output,
or accept data from standard input. This can be confusing at first in the
VxWorks Shell, because the standard output and input streams are not
necessarily directed to the same window as the shell. In fact the default
setting in VxWorks is direct everything to the serial console(port).
For example, if your application program does a printf, you will not see
the item to be printed on the shell window.
Syntax
To designate a standard I/O device, execute the target routine
ioGlobalStdSet() in WindSh. For example, the following sequence
of commands resets standard input, standard output, and standard error to
virtual I/O channel 0:
-> vf0=open("/vio/0",2,0) /* Creating virtual I/O Channel */
-> ioGlobalStdSet(0,vf0) /* Redirecting Standard In */
-> ioGlobalStdSet(1,vf0) /* Redirecting Standard Out */
-> ioGlobalStdSet(2,vf0) /* Redirecting Standard Error */
Notes:
o These sequence of instructions can be added to application source code
for automatic execution at run time or can be stored in a script file to be
loaded and executed from the shell.
o If after performing these steps IO still does not show up on the virtual
console, you must reboot the VME board and start over.
Additional Information
Please see the VxWorks User's manual for further information.
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Last Updated: 09 November 1998
Created by: Dan Eyassu
eyassud@db.erau.edu