Check if the output file already exists - and open it in append mode then.

git-svn-id: http://svn.cactuscode.org/arrangements/CactusPUGHIO/IOHDF5/trunk@107 4825ed28-b72c-4eae-9704-e50c059e567d

1 files changed, 9 insertions, 3 deletions

diff --git a/src/util/hdf5_merge.c b/src/util/hdf5_merge.c
index 3614bc3..29139ef 100644
--- a/src/util/hdf5_merge.c
+++ b/src/util/hdf5_merge.c
@@ -121,11 +121,17 @@ int main (int argc, char *argv[])
       }
     }
 
-    /* create output file */
-    outfile = H5Fcreate (argv[argc-1], H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+    /* try to open an existing outfile file in append mode,
+       if this fails create it as a new file */
+    outfile = H5Fopen (argv[argc-1], H5F_ACC_RDWR, H5P_DEFAULT);
     if (outfile < 0)
     {
-      fprintf (stderr, "ERROR: Cannot create HDF5 output file '%s' !\n\n",
+      outfile = H5Fcreate (argv[argc-1], H5F_ACC_TRUNC, H5P_DEFAULT,
+                           H5P_DEFAULT);
+    }
+    if (outfile < 0)
+    {
+      fprintf (stderr, "ERROR: Cannot open HDF5 output file '%s' !\n\n",
                argv[argc - 1]);
       return (-1);
     }