perror(3C) — sys5 — Apollo Domain/IX SR9.5



PERROR(3C)               DOMAIN/IX SYS5                PERROR(3C)



NAME
     perror, sys_errlist, sys_ner - system error messages

USAGE
     perror(s)
     char *s;

     int sys_nerr;
     char *sys_errlist[];


DESCRIPTION
     Perror produces a short error message on the standard error
     file that describes the error that a C program encountered
     during its most recent call to the system.  The argument
     string s is printed first, followed by a colon, the message,
     and a new-line.  The argument string is the name of the pro-
     gram that caused the error.  The error number is taken from
     the external variable errno, which is set when errors occur.

     The vector of message strings, sys_errlist, is provided to
     simplify the message formats.  Use errno as an index into
     this table to get the message string without the newline.
     Sys_nerr is the number of messages provided for in the
     table; it should be checked, because new error codes may be
     added to the system before they are added to the table.

NOTES
     Errno is only set when an error occurs.  It is not cleared
     when a valid call is made.























Printed 12/4/86                                          PERROR-1
Museum
