NAME    [Toc]    [Back]

       com_err - common error display routine

SYNOPSIS    [Toc]    [Back]

        #include <com_err.h>

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

       proc = set_com_err_hook (proc);
       void  (*  proc  )  (const  char  *,  long,  const  char *,
       va_list);

       proc = reset_com_err_hook ();

       void initialize_XXXX_error_table ();

DESCRIPTION    [Toc]    [Back]

       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
 arguments, 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  program
       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 declaration 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    [Toc]    [Back]

       compile_et (1), syslog (3).

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


SIPB                       22 Nov 1988                          2