cli: Introduce a logfile command to log errors to a file
The evolution would be to introduce libosmocore and start using
the logging framework. But even then we can map this option to
the file target.
Fixes: SYS#263
diff --git a/lib/syserr.h b/lib/syserr.h
index e3ebdf0..a65dfc3 100644
--- a/lib/syserr.h
+++ b/lib/syserr.h
@@ -14,6 +14,8 @@
#define SYSERR_MSGSIZE 256
+void sys_err_setlogfile(FILE*);
+
void sys_err(int pri, char *filename, int en, int line, char *fmt, ...);
void sys_errpack(int pri, char *fn, int ln, int en, struct sockaddr_in *peer,
void *pack, unsigned len, char *fmt, ...);