Fix G_snprintf() to allow for bug in Windows vsnprintf()

Change G_vasprintf() to use vsnprintf instead of temporary file


git-svn-id: https://svn.osgeo.org/grass/grass/trunk@40839 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/gis/asprintf.c

@@ -6,39 +6,23 @@
  *
  * Eric G. Miller - Thu, 2 May 2002 17:51:54 -0700
  *
- * I've got a sort of cheat for asprintf. We can't use vsnprintf for the
- * same reason we can't use snprintf ;-)  Comments welcome.
- *
- * We cheat by printing to a tempfile via vfprintf() and then reading it
- * back in. Probably not the most efficient way.
- *
- * <b>WARNING:</b> Temporarily, the G_asprintf macro cannot be used. See 
- * explanation in gisdefs.h.
+ * Rewritten by Glynn Clements, Sat, 6 Feb 2010
+ * Assumes that vsnprintf() is available
  *
  * (C) 2001-2008 by the GRASS Development Team
+ * (C) 2010 by Glynn Clements
  *
  * This program is free software under the GNU General Public License
  * (>=v2). Read the file COPYING that comes with GRASS for details.
- *
- * \author Eric Miller - egm2 at jps net
- *
- * \date 2002-2008
  */
 
 #define _GNU_SOURCE		/* enable asprintf */
 #include <grass/config.h>
 #include <stdio.h>
-#include <stdlib.h>
 #include <stdarg.h>
-#include <unistd.h>
-#include <assert.h>
+#include <string.h>
 #include <grass/gis.h>
 
-#ifdef __MINGW32__
-#include <windows.h>
-#endif /* __MINGW32__ */
-
-
 #ifndef G_asprintf
 
 /**
@@ -54,64 +38,29 @@
  * \return number of bytes written
  */
 
-#ifdef HAVE_ASPRINTF
-
 int G_vasprintf(char **out, const char *fmt, va_list ap)
 {
+#ifdef HAVE_ASPRINTF
     return vasprintf(out, fmt, ap);
-}
-
 #else
+    size_t size = strlen(fmt) + 50;
+    char *buf = G_malloc(size);
+    int count;
 
-int G_vasprintf(char **out, const char *fmt, va_list ap)
-{
-    int ret_status = EOF;
-    char dir_name[2001];
-    char file_name[2000];
-    FILE *fp = NULL;
-    char *work = NULL;
-
-    assert(out != NULL && fmt != NULL);
-
-    /* Warning: tmpfile() does not work well on Windows (MinGW)
-     *          if user does not have write access on the drive where 
-     *          working dir is? */
-#ifdef __MINGW32__
-    /* file_name = G_tempfile(); */
-    GetTempPath(2000, dir_name);
-    GetTempFileName(dir_name, "asprintf", 0, file_name);
-    fp = fopen(file_name, "w+");
-#else
-    fp = tmpfile();
-#endif /* __MINGW32__ */
-
-    if (fp) {
-	int count;
-
-	count = vfprintf(fp, fmt, ap);
-	if (count >= 0) {
-	    work = G_calloc(count + 1, sizeof(char));
-	    if (work != NULL) {
-		rewind(fp);
-		ret_status = fread(work, sizeof(char), count, fp);
-		if (ret_status != count) {
-		    ret_status = EOF;
-		    G_free(work);
-		    work = NULL;
-		}
-	    }
-	}
-	fclose(fp);
-#ifdef __MINGW32__
-	unlink(file_name);
-#endif /* __MINGW32__ */
+    for (;;) {
+	count = vsnprintf(buf, size, fmt, ap);
+	if (count >= 0 && count < size)
+	    break;
+	size *= 2;
+	buf = G_realloc(buf, size);
     }
-    *out = work;
 
-    return ret_status;
-}
+    buf = G_realloc(buf, count + 1);
+    *out = buf;
 
+    return count;
 #endif /* HAVE_ASPRINTF */
+}
 
 int G_asprintf(char **out, const char *fmt, ...)
 {

lib/gis/snprintf.c

@@ -27,8 +27,6 @@
 #include <assert.h>
 #include <grass/gis.h>
 
-/* #ifdef HAVE_SNPRINTF */
-
 /**
  * \brief snprintf() clone.
  *
@@ -51,7 +49,9 @@ int G_snprintf(char *str, size_t size, const char *fmt, ...)
     count = vsnprintf(str, size, fmt, ap);
     va_end(ap);
 
+    /* Windows' vsnprintf() doesn't always NUL-terminate the buffer */
+    if (count == size)
+	str[--count] = '\0';
+
     return count;
 }
-
-/* #endif */