COMER(3)                                                          COMER(3)



NAME
       comerr - common error display routine

SYNOPSIS
        #include 

       void comerr (whoami, code, format, ...);
            const char *whoami;
            long code;
            const char *format;

       proc = setcomerrhook (proc);
       void (* proc ) (const char *, long, const char *, valist);

       proc = resetcomerrhook ();

       void initializeXerrortable ();

DESCRIPTION
       Comerr  displays  an error message on the standard error stream stderr
       (see stdio(3S)) composed of the whoami string, which should specify the
       program name or some subportion of a program, followed by an error mes-
       sage generated from the code value (derived from compileet(1)), and  a
       string produced using the format string and any following arguments, in
       the same style as fprintf(3).

       The behavior of comerr can be modified  using  setcomerrhook;  this
       defines  a  procedure  which  is  called  with  the arguments passed to
       comerr, instead of the default internal procedure which sends the for-
       matted  text  to  error output.  Thus the error messages from a program
       can all easily be diverted to another form of diagnostic logging,  such
       as  syslog(3).   Resetcomerrhook may be used to restore the behavior
       of comerr to its default form.  Both procedures  return  the  previous
       ``hook''  value.   These  ``hook'' procedures must have the declaration
       given for proc above in the synopsis.

       The initializeXerrortable routine is  generated  mechanically  by
       compileet(1)  from  a  source  file  containing  names  and associated
       strings.  Each table has a name of up to four characters, which is used
       in place of the X in the name of the routine.  These routines should
       be called before any of the corresponding error codes are used, so that
       the  comerr  library will recognize error codes from these tables when
       they are used.

       The comerr.h header file should be included in any  source  file  that
       uses routines from the comerr library; executable files must be linked
       using ``-lcomerr'' in  order  to  cause  the  comerr  library  to  be
       included.



SEE ALSO
       compileet (1), syslog (3).

       Ken Raeburn, "A Common Error Description Library for UNIX".



SIPB                              22 Nov 1988                       COMER(3)