Description
bool
openlog ( string ident, int option, int facility )
openlog() opens a connection to the system
logger for a program. The string ident is
added to each message. Values for option
and facility are given below.
The option argument is used to indicate
what logging options will be used when generating a log message.
The facility argument is used to specify what
type of program is logging the message. This allows you to specify
(in your machine's syslog configuration) how messages coming from
different facilities will be handled.
The use of openlog() is optional. It
will automatically be called by syslog() if
necessary, in which case ident will default
to FALSE.
Table 1. openlog() Options
| Constant | Description |
|---|
| LOG_CONS |
if there is an error while sending data to the system logger,
write directly to the system console
|
| LOG_NDELAY |
open the connection to the logger immediately
|
| LOG_ODELAY |
(default) delay opening the connection until the first
message is logged
|
| LOG_PERROR | print log message also to standard error |
| LOG_PID | include PID with each message |
You can use one or more of this options. When using multiple options
you need to
OR them, i.e. to open the connection
immediately, write to the console and include the PID in each message,
you will use:
LOG_CONS | LOG_NDELAY | LOG_PID
Table 2. openlog() Facilities
| Constant | Description |
|---|
| LOG_AUTH |
security/authorization messages (use LOG_AUTHPRIV instead
in systems where that constant is defined)
|
| LOG_AUTHPRIV | security/authorization messages (private) |
| LOG_CRON | clock daemon (cron and at) |
| LOG_DAEMON | other system daemons |
| LOG_KERN | kernel messages |
| LOG_LOCAL0 ... LOG_LOCAL7 | reserved for local use, these are not available in Windows |
| LOG_LPR | line printer subsystem |
| LOG_MAIL | mail subsystem |
| LOG_NEWS | USENET news subsystem |
| LOG_SYSLOG | messages generated internally by syslogd |
| LOG_USER | generic user-level messages |
| LOG_UUCP | UUCP subsystem |
Note:
LOG_USER is the only valid log type under Windows
operating systems
See also define_syslog_variables(),
syslog() and
closelog().
