Index: /branches/eam_branches/ipp-20140206/Ohana/src/relphot/src/launch_region_hosts.c
===================================================================
--- /branches/eam_branches/ipp-20140206/Ohana/src/relphot/src/launch_region_hosts.c	(revision 36547)
+++ /branches/eam_branches/ipp-20140206/Ohana/src/relphot/src/launch_region_hosts.c	(revision 36548)
@@ -4,11 +4,10 @@
 int strextend (char *input, char *format,...) {
 
-  char tmpfmt[1024], tmpline[1024];
+  char tmpextra[1024], tmpline[1024];
   va_list argp;
 
   va_start (argp, format);
-  
-  snprintf (tmpfmt, 1024, "%%s %s", format);
-  vsnprintf (tmpline, 1024, tmpfmt, argp);
+  vsnprintf (tmpextra, 1024, format, argp);
+  snprintf (tmpline, 1024, "%s %s", input, tmpextra);
   strcpy (input, tmpline);
 
Index: /branches/eam_branches/ipp-20140206/Ohana/src/relphot/src/syncfile.c
===================================================================
--- /branches/eam_branches/ipp-20140206/Ohana/src/relphot/src/syncfile.c	(revision 36548)
+++ /branches/eam_branches/ipp-20140206/Ohana/src/relphot/src/syncfile.c	(revision 36548)
@@ -0,0 +1,77 @@
+# include "relphot.h"
+# define MSG_LENGTH 12
+
+char *make_filename (char *dirname, char *hostname, int hostID, char *tailname) {
+
+  char tmp[10], *line; 
+  int Nchar = snprintf (tmp, 0, "%s/%s.%03d.%s", dirname, hostname, hostID, tailname);
+  
+  ALLOCATE (line, char, Nchar + 1);
+  snprintf (line, Nchar + 1, "%s/%s.%03d.%s", dirname, hostname, hostID, tailname);
+
+  return line;
+}
+
+int check_sync_file (char *filename, int nloop) {
+
+  char message[MSG_LENGTH];
+
+  FILE *f = NULL; 
+
+  while (TRUE) {
+
+    f = fopen (filename, "r");
+    if (!f) {
+      usleep (2000000);
+      continue;
+    }
+
+    // XXX MSG_LENGTH : 0 EOL byte?
+    int Nread = fread (message, 1, MSG_LENGTH, f);
+    if (Nread < MSG_LENGTH) {
+      fclose (f);
+      usleep (2000000);
+      continue;
+    }
+    fclose (f);
+
+    // message is of the form: NLOOP: %03d
+    int loop;
+    sscanf (message, "%*s %d", &loop);
+    if (loop != nloop) {
+      usleep (2000000);
+      continue;
+    }
+    return TRUE;
+  }
+  return FALSE;
+}
+
+int clear_sync_file (char *filename) {
+  // delete file contents
+  truncate (filename, 0);
+
+  return TRUE;
+}
+
+int update_sync_file (char *filename, int nloop) {
+
+  char message[MSG_LENGTH];
+
+  FILE *f = fopen (filename, "w");
+  if (!f) { 
+    fprintf (stderr, "failure to open sync file for write\n");
+    exit (4);
+  }
+
+  snprintf (message, MSG_LENGTH, "NLOOP: %03d\n", nloop);
+  
+  int Nwrite = fwrite (message, 1, MSG_LENGTH, f);
+  if (Nwrite != MSG_LENGTH) {
+    fprintf (stderr, "failure to write sync message\n");
+    exit (3);
+  }
+
+  fclose (f);
+  return TRUE;
+}