IOPRO_WAIT(8) BSD System Manager's Manual IOPRO_WAIT(8) NAME iopro_wait - Wait for an IOPRO data port to be configured SYNOPSIS /usr/libexec/iopro_wait [-v] [device] DESCRIPTION The external units used in the Chase Research IOPRO system may be powered independently from the host system. When they are powered up ( or at sys- tem startup time ) they need to be downloaded and configured by the sup- port daemon ioprod(8) before the data ports are used. To prevent use before the ports have been configured the data driver will block open(2) calls on the ports in a similar way to waiting for carrier. If a non-blocking open is performed then the driver will cancel the open attempt and return the error code EAGAIN to indicate that the port is temporarily unavailable. Most system daemons and programs work well with the above scheme but a few take the EAGAIN error from a non-blocking open to indicate that the resource is permanently unavailable and fail. iopro_wait program is a simple fix for these daemons. Called before the daemon in question with the name of the device that it is going to use iopro_wait will block until the port has been configured. The daemon will then be able to access the device without seeing the error return. EXAMPLES For a daemon foobar that uses the port /dev/tty7d the following would re- place foobar & in the system startup scripts. (/usr/libexec/iopro_wait /dev/tty7d && foobar) & DIAGNOSTICS Should be self explanatory. You can add warm and fuzzys with the -v flag. BUGS Do not place iopro_wait in the system startup scripts in a position where it could block the starting of ioprod or the system will wait forever. SEE ALSO ioprod(8) open(2) BSD/OS 28 Jul 95 1[top]
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