In the elogd.c file nearly at the very top is the following line:

char svn_revision[] = "$Id: elogd.c 2411 2011-04-01 14:39:35Z ritt $";

How does this information get into the source file?  Is it a script used when the svn changes are committed, or perhaps when they are checked out?  Any details or pointers to info on the web would be greatly appreciated.

Thanks.