com_err

COM_ERR(3)							   COM_ERR(3)



NAME
       com_err - common error display routine

SYNOPSIS
	#include <et/com_err.h>
       void (*proc) (const char *, long, const char *, va_list);

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

       proc = set_com_err_hook (proc);

       proc = reset_com_err_hook ();

       void initialize_XXXX_error_table ();

DESCRIPTION
       Com_err	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
       message generated from the code value  (derived	from  compile_et(1)),
       and  a string produced using the format string and any following argu-
       ments, in the same style as fprintf(3).

       The behavior of com_err can be modified using  set_com_err_hook;	 this
       defines	a  procedure  which  is	 called	 with the arguments passed to
       com_err, instead of the default internal	 procedure  which  sends  the
       formatted  text	to error output.  Thus the error messages from a pro-
       gram can all easily be diverted to another form of diagnostic logging,
       such  as	 syslog(3).   Reset_com_err_hook  may  be used to restore the
       behavior of com_err to its default form.	 Both procedures  return  the
       previous ‘‘hook’’ value.	 These ‘‘hook’’ procedures must have the dec-
       laration given for proc above in the synopsis.

       The initialize_XXXX_error_table routine is generated  mechanically  by
       compile_et(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 XXXX in the name of the routine.  These routines
       should be called before any of the corresponding error codes are used,
       so  that	 the  com_err  library	will recognize error codes from these
       tables when they are used.

       The com_err.h header file should be included in any source  file	 that
       uses  routines  from  the  com_err  library;  executable files must be
       linked using ‘‘-lcom_err’’ in order to cause the com_err library to be
       included.



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

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



SIPB				 22 Nov 1988			   COM_ERR(3)