perror(3C)                                             perror(3C)



NAME
     perror, strerror, errno, syserrlist, sysnerr - system
     error messages

SYNOPSIS
     void perror (s)
     char *s;

     char *strerror (errnum)
     int errnum;

     extern int errno;

     extern char *syserrlist[ ];

     extern int sysnerr;

DESCRIPTION
     perror produces a message on the standard error output,
     describing the last error encountered during a call to a
     system or library function.  The argument string s is
     printed first, then a colon and a blank, then the message
     and a new-line.  To be of most use, the argument string
     should include the name of the program that incurred the
     error.  The error number is taken from the external variable
     errno, which is set when errors occur but not cleared when
     non-erroneous calls are made.

     To simplify variant formatting of messages, the array of
     message strings syserrlist is provided; errno can be used
     as an index in this table to get the message string without
     the new-line.  Sysnerr is the largest message number pro-
     vided 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.

     Strerror returns a pointer to the error message string from
     the syserrlist array, indexed by errnum.  The string
     returned shall not be modified by the program, but may be
     overwritten by a subsequent call to the strerror function.

SEE ALSO
     intro(2).












Page 1                        CX/UX Programmer's Reference Manual