SYNTAX

       #include "logmsg.h"

       int logmsg(char *who, int ecode, unsigned int classs, char *msg)

       err_sys(w,e) logmsg(w,e,FATAL,"")
       err_sys_plus(w,e,m) logmsg(w,e,FATAL,m)
       err_tmp(w,e) logmsg(w,e,WARN,"")
       err_tmp_plus(w,e,m) logmsg(w,e,WARN,m)
       err_int(w,e,c) logmsg(w,e,c,"")
       err_int_plus(w,e,c,m) logmsg(w,e,c,m)
       log(w,m) logmsg(w,0,LOG,m)
       log_anon(m) logmsg("",0,LOG,m)


DESCRIPTION

       logmsg prints error, warning, or info/logging messages to stderr and
       potentially terminates the calling program, depending on the class
       given.  who is the name of the program, ecode is an error code, class
       determines the behavior upon call and msg is the logging message.  Read
       "error.h" to learn related constants.


ECODE

       ecode is the error code and subject to be displayed in the log file and
       potentially used upon exit in case the class equals FATAL or DROP.

       To avoid conflicts with syscall error codes, appplication defined error
       codes should be negative.  The values -15, -100 and -111 are reserved
       for backwards compatibility.


CLASS

       The class parameter indicates how the application handles exceptions
       and displays the log message.

       o   LOG, INFO, WARN - display message and continue operation

       o   DROP - display warning message and continue while going to the
           calling program

       o   USAGE, SYNTAX, FATAL, ERROR - display error message and exit
           application with error code

       INFO, WARN, DROP, USAGE, and FATAL as well as ERROR display the
       respective class string like warn: in the log message, while LOG shows
       the log message only.

       The class FATAL should be used for system error codes only, rather
       ERROR and WARN shall be set in conjunction with an application
       error/warning.


MESSAGE

       If the custom message msg is given, it will be printed additionally.

FORMAT

       The log message format consists of the tokens who: (ecode) msg :
       errmsg.  ecode is displayed only for classes FATAL, ERROR, or DROP.
       errmsg is the system's explanation according to the variable errno if
       provided.

NOTES

       logmsg.c uses errstr.c routines.  Error codes and classes are defined
       in error.h and included by logmsg.h.

EXIT CODE

       logmsg exits ecode for classes ERROR, FATAL, SYNTAX, and USAGE
       terminating the application.


HISTORY

       Dan Bernstein used sets of strerr_dieY*() and strerr_warnY() messages
       which explicitely determine the message and behavior class.  Other
       classes were occasionally defined on demand, such als usage().

       Kai Peter introduced the errmsg facility in his qlibs including a
       syslog compliant severity as second parameter.


EXAMPLES

       The macro definitions uses  w for the calling program, e for error
       code, c for class and m for message.

         #include "logmsg.h"
         #define WHO "my_prog"

         err_sys(WHO,errno);
         err_sys_plus(WHO,-111,"additional message");

         err_tmp("",-100);
         err_tmp("",errno,"additional message");

         log(WHO,"message");

       log_anon() is like log() but doesn't print the caller name.

       An user defined message s can be build from multiple arguments by using
       the B (build) macro:

         err_sys_plus((errno),B("unable to run: ",*argv));


SEE ALSO

       syslog(3)



                                       3                        qlibs:(logmsg)

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