Allow setting facility and options in openlog.

Modify openlog to an arity of 3. Provide some functions for retrieving
syslog constants.

c_src/syslog.c

@@ -32,14 +32,18 @@ THE SOFTWARE.
 
 #define MAXBUFLEN 1024
 
-char facil[MAXBUFLEN];
+const char ident[MAXBUFLEN];
 
 
 static ERL_NIF_TERM nif_open(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
-    if (enif_get_string(env, argv[0], facil, sizeof(facil), ERL_NIF_LATIN1) < 1) {
+    int option;
+    int facility;
+    if ( (enif_get_string(env, argv[0], (char *)ident, sizeof(ident), ERL_NIF_LATIN1) < 1) ||
+         !enif_get_int(env, argv[1], &option) ||
+         !enif_get_int(env, argv[2], &facility)) {
         return enif_make_badarg(env);
     }
-    openlog(facil, LOG_CONS | LOG_PID, 0);
+    openlog(ident, option, facility);
     return enif_make_atom(env, "ok");
 }
 
@@ -62,7 +66,7 @@ static ERL_NIF_TERM nif_close(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[
 }
 
 static ErlNifFunc nif_funcs[] = {
-    {"open", 1, nif_open},
+    {"open", 3, nif_open},
     {"write", 2, nif_write},
     {"close", 0, nif_close}
 };

src/syslog.erl

@@ -21,7 +21,8 @@
 %% FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 %% OTHER DEALINGS IN THE SOFTWARE.
 -module(syslog).
--export([open/1, write/2, close/0]).
+-export([open/1, open/3, write/2, close/0,
+         option/1, facility/1, level/1]).
 -on_load(on_load/0).
 
 on_load() ->
@@ -33,9 +34,53 @@ on_load() ->
         ]),
     erlang:load_nif(Lib, 0).
 
-open(_) -> erlang:error(not_implemented).
+open(Ident) ->
+    open(Ident, option(pid) bxor option(cons), level(info)).
+
+open(_,_,_) -> erlang:error(not_implemented).
 
 write(_,_) -> erlang:error(not_implemented).
 
 close() -> erlang:error(not_implemented).
 
+
+% options for openlog()
+option(pid) -> 16#01;       % log the pid with each message
+option(cons) -> 16#02;      % log on the console if errors in sending
+option(odelay) -> 16#04;    % delay open until first syslog() (default)
+option(ndelay) -> 16#08;    % don't delay open
+option(nowait) -> 16#10;    % don't wait for console forks: DEPRECATED
+option(perror) -> 16#20.    % log to stderr as well
+
+%% specify the type of program logging the message
+facility(kern) -> 0 bsl 3;      % kernel messages
+facility(user) -> 1 bsl 3;      % random user-level messages
+facility(mail) -> 2 bsl 3;      % mail system
+facility(daemon) -> 3 bsl 3;    % system daemons
+facility(auth) -> 4 bsl 3;      % security/authorization messages
+facility(syslog) -> 5 bsl 3;    % messages generated internally by syslogd
+facility(lpr) -> 6 bsl 3;       % line printer subsystem
+facility(news) -> 7 bsl 3;      % network news subsystem
+facility(uucp) -> 8 bsl 3;      % UUCP subsystem
+facility(cron) -> 9 bsl 3;      % clock daemon
+facility(authpriv) -> 10 bsl 3; % security/authorization messages (private)
+facility(ftp) -> 11 bsl 3;      % ftp daemon
+
+facility(local0) -> 16 bsl 3;   % reserved for local use
+facility(local1) -> 17 bsl 3;   % reserved for local use
+facility(local2) -> 18 bsl 3;   % reserved for local use
+facility(local3) -> 19 bsl 3;   % reserved for local use
+facility(local4) -> 20 bsl 3;   % reserved for local use
+facility(local5) -> 21 bsl 3;   % reserved for local use
+facility(local6) -> 22 bsl 3;   % reserved for local use
+facility(local7) -> 23 bsl 3.   % reserved for local use
+
+%% importance of message
+level(emerg) -> 0;
+level(alert) -> 1;
+level(crit) -> 2;
+level(err) -> 3;
+level(warning) -> 4;
+level(notice) -> 5;
+level(info) -> 6;
+level(debug) -> 7.