Extract function to compose file names.

* This enables nicer failure modes for long file names and better
  diagnostics.

tests/deco2d_model.c

@@ -86,7 +86,7 @@ modelRun(struct model_config setup, MPI_Comm comm)
   time_t current_time;
   int vdate = 19850101, vtime = 120000;
   int rank = 0;
-  char filename[1024];
+  char *filename = NULL;
   int nlon = setup.nlon, nlat = setup.nlat;
   size_t nVars = setup.nvars > 0 ? (size_t) setup.nvars : 0;
   size_t varslice_size = 0;
@@ -235,7 +235,7 @@ modelRun(struct model_config setup, MPI_Comm comm)
   taxisID = taxisCreate(TAXIS_ABSOLUTE);
   vlistDefTaxis(vlistID, taxisID);
 
-  sprintf(&filename[0], "%s_%d.%s", fname_prefix, tfID, setup.suffix);
+  composeFilename(&filename, fname_prefix, tfID, setup.suffix);
   streamID = streamOpenWrite(filename, setup.filetype);
   xassert(streamID >= 0);
   streamDefVlist(streamID, vlistID);
@@ -250,7 +250,8 @@ modelRun(struct model_config setup, MPI_Comm comm)
       if (tfID > 0)
         {
           streamClose(streamID);
-          sprintf(&filename[0], "%s_%d.%s", fname_prefix, tfID, setup.suffix);
+
+          composeFilename(&filename, fname_prefix, tfID, setup.suffix);
           streamID = streamOpenWrite(filename, setup.filetype);
           xassert(streamID >= 0);
           streamDefVlist(streamID, vlistID);
@@ -338,7 +339,7 @@ modelRun(struct model_config setup, MPI_Comm comm)
         {
           FILE *tablefp;
           {
-            sprintf(filename, "%s_%d.cksum", fname_prefix, tfID);
+            composeFilename(&filename, fname_prefix, tfID, "cksum");
             if (!(tablefp = fopen(filename, "w")))
               {
                 perror("failed to open table file");
@@ -389,6 +390,7 @@ modelRun(struct model_config setup, MPI_Comm comm)
 #endif
   Free(varDesc);
   Free(levs);
+  Free(filename);
 }
 
 #ifdef USE_MPI

tests/simple_model.c

@@ -78,7 +78,7 @@ modelRun(struct model_config setup, MPI_Comm comm)
   time_t current_time;
   int vdate = 19850101, vtime = 120000;
   int rank = 0;
-  char filename[1024];
+  char *filename = NULL;
   int nlon = setup.nlon, nlat = setup.nlat;
   size_t nVars = (size_t) setup.nvars;
   size_t varslice_size = 0;
@@ -175,7 +175,8 @@ modelRun(struct model_config setup, MPI_Comm comm)
   taxisID = taxisCreate(TAXIS_ABSOLUTE);
   vlistDefTaxis(vlistID, taxisID);
 
-  sprintf(&filename[0], "%s_%d.%s", fname_prefix, tfID, setup.suffix);
+  composeFilename(&filename, fname_prefix, tfID, setup.suffix);
+
   streamID = streamOpenWrite(filename, setup.filetype);
   xassert(streamID >= 0);
   streamDefVlist(streamID, vlistID);
@@ -190,7 +191,8 @@ modelRun(struct model_config setup, MPI_Comm comm)
       if (tfID > 0)
         {
           streamClose(streamID);
-          sprintf(&filename[0], "%s_%d.%s", fname_prefix, tfID, setup.suffix);
+
+          composeFilename(&filename, fname_prefix, tfID, setup.suffix);
           streamID = streamOpenWrite(filename, setup.filetype);
           xassert(streamID >= 0);
           streamDefVlist(streamID, vlistID);
@@ -265,7 +267,7 @@ modelRun(struct model_config setup, MPI_Comm comm)
         {
           FILE *tablefp;
           {
-            sprintf(filename, "%s_%d.cksum", fname_prefix, tfID);
+            composeFilename(&filename, fname_prefix, tfID, "cksum");
             if (!(tablefp = fopen(filename, "w")))
               {
                 perror("failed to open table file");
@@ -318,6 +320,7 @@ modelRun(struct model_config setup, MPI_Comm comm)
 #endif
   Free(varDesc);
   Free(levs);
+  Free(filename);
 }
 
 /*

tests/simple_model_helper.c

@@ -5,6 +5,7 @@
 #include <inttypes.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include "cdi.h"
 #include "dmemory.h"
@@ -63,6 +64,24 @@ time_t2cditime(time_t t, int *date, int *timeofday)
   *timeofday = t_s->tm_hour * 10000 + t_s->tm_min * 100 + t_s->tm_sec;
 }
 
+void
+composeFilename(char **buf, const char *fname_prefix, int tfID, const char *suffix)
+{
+  size_t fnSize = strlen(fname_prefix) + 1 + sizeof(int) * 3 + 1 + strlen(suffix) + 1;
+  char *filename = Realloc(*buf, fnSize);
+  int plen;
+  if ((size_t) (plen = snprintf(filename, fnSize, "%s_%d.%s", fname_prefix, tfID, suffix)) >= fnSize)
+    {
+      fprintf(stderr,
+              "unexpected error: printing to string of size %zu"
+              " results in %d chars to write\n",
+              fnSize, plen);
+      abort();
+    }
+  filename[fnSize - 1] = 0;
+  *buf = filename;
+}
+
 #if defined USE_MPI && !defined HAVE_PPM_CORE
 
 static int32_t uniform_partition_start(struct PPM_extent set_interval, int nparts, int part_idx);
@@ -113,3 +132,13 @@ PPM_prime_factorization_32(uint32_t n, uint32_t **factors)
 }
 
 #endif
+
+/*
+ * Local Variables:
+ * c-file-style: "Java"
+ * c-basic-offset: 2
+ * indent-tabs-mode: nil
+ * show-trailing-whitespace: t
+ * require-trailing-newline: t
+ * End:
+ */

tests/simple_model_helper.h

@@ -36,6 +36,8 @@ dg_wobble(double frac_x, double frac_y, double mscale, double mrscale)
 time_t cditime2time_t(int date, int timeofday);
 void time_t2cditime(time_t t, int *date, int *timeofday);
 
+void composeFilename(char **buf, const char *fname_prefix, int tfID, const char *suffix);
+
 #if defined(USE_MPI) && !defined(HAVE_PPM_CORE)
 struct PPM_extent
 {