perror(3C)                                             perror(3C)



     NAME
          perror, errno, sys_errlist, sys_nerr - system error messages

     SYNOPSIS
          void perror(s)
          char *s;

          extern int errno;

          extern char *sys_errlist[];

          extern int sys_nerr;

     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 print-
          ed first, then a colon and a blank, then the message and a
          newline.  To be of most use, the argument string should in-
          clude 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 noner-
          roneous calls are made.

          To simplify variant formatting of messages, the array of
          message strings sys_errlist is provided; errno can be used
          as an index in this table to get the message string without
          the newline.  sys_nerr is the largest message number provid-
          ed 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.

     SEE ALSO
          intro(2).





















     April, 1990                                                     1