ERROR(M)                 XENIX System V                  ERROR(M)



     Name
          error - Kernel error output device.

     Description
          System error messages are collected and made available to
          error logging daemons through the /dev/error device.
          /dev/error is a read-only device which returns one error per
          read and no EOF character.  /etc/rc uses a utility to read
          messages from /dev/error and write them to the system error
          log file /usr/adm/messages:

               /etc/logger /dev/error /usr/adm/messages &

          Any process can read /dev/error or arrange to be signaled
          when errors are queued in /dev/error.  The following ioctl
          causes the error device to signal the process with SIGUSR1
          when an error message is queued in /dev/error.

               #include <signal.h>
               #include <syserr.h>
               ...
               int fd;
               ...
               fd = open("/dev/error", O_RDONLY);
               ioctl(fd, EMSG_SIG, SIGUSR1);

          Before exiting, the process must return /dev/error to its
          normal state.  Do this with the following ioctl:

               ...
               ioctl(fd,EMSG_NOSIG, 0);
               ...

          Panic error messages are not logged in /dev/error.

     Files
          /dev/error

     See Also
          messages(M)















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