Import BSDDB 4.7.25 (as of svn r89086)

os_windows/os_getenv.c

@@ -0,0 +1,102 @@
+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 1997,2008 Oracle.  All rights reserved.
+ *
+ * $Id: os_getenv.c 63573 2008-05-23 21:43:21Z trent.nelson $
+ */
+
+#include "db_config.h"
+
+#include "db_int.h"
+
+/*
+ * __os_getenv --
+ *	Retrieve an environment variable.
+ */
+int
+__os_getenv(env, name, bpp, buflen)
+	ENV *env;
+	const char *name;
+	char **bpp;
+	size_t buflen;
+{
+#ifdef DB_WINCE
+	COMPQUIET(name, NULL);
+	/* WinCE does not have a getenv implementation. */
+	return (0);
+#else
+	_TCHAR *tname, tbuf[1024];
+	int ret;
+	char *p;
+
+	/*
+	 * If there's a value and the buffer is large enough:
+	 *	copy value into the pointer, return 0
+	 * If there's a value and the buffer is too short:
+	 *	set pointer to NULL, return EINVAL
+	 * If there's no value:
+	 *	set pointer to NULL, return 0
+	 */
+	if ((p = getenv(name)) != NULL) {
+		if (strlen(p) < buflen) {
+			(void)strcpy(*bpp, p);
+			return (0);
+		}
+		goto small_buf;
+	}
+
+	TO_TSTRING(env, name, tname, ret);
+	if (ret != 0)
+		return (ret);
+	/*
+	 * The declared size of the tbuf buffer limits the maximum environment
+	 * variable size in Berkeley DB on Windows.  If that's too small, or if
+	 * we need to get rid of large allocations on the BDB stack, we should
+	 * malloc the tbuf memory.
+	 */
+	ret = GetEnvironmentVariable(tname, tbuf, sizeof(tbuf));
+	FREE_STRING(env, tname);
+
+	/*
+	 * If GetEnvironmentVariable succeeds, the return value is the number
+	 * of characters stored in the buffer pointed to by lpBuffer, not
+	 * including the terminating null character.  If the buffer is not
+	 * large enough to hold the data, the return value is the buffer size,
+	 * in characters, required to hold the string and its terminating null
+	 * character.  If GetEnvironmentVariable fails, the return value is
+	 * zero.  If the specified environment variable was not found in the
+	 * environment block, GetLastError returns ERROR_ENVVAR_NOT_FOUND.
+	 */
+	if (ret == 0) {
+		if ((ret = __os_get_syserr()) == ERROR_ENVVAR_NOT_FOUND) {
+			*bpp = NULL;
+			return (0);
+		}
+		__db_syserr(env, ret, "GetEnvironmentVariable");
+		return (__os_posix_err(ret));
+	}
+	if (ret > (int)sizeof(tbuf))
+		goto small_buf;
+
+	FROM_TSTRING(env, tbuf, p, ret);
+	if (ret != 0)
+		return (ret);
+	if (strlen(p) < buflen)
+		(void)strcpy(*bpp, p);
+	else
+		*bpp = NULL;
+	FREE_STRING(env, p);
+	if (*bpp == NULL)
+		goto small_buf;
+
+	return (0);
+
+small_buf:
+	*bpp = NULL;
+	__db_errx(env,
+	    "%s: buffer too small to hold environment variable %s",
+	    name, p);
+	return (EINVAL);
+#endif
+}