add file operations table and make all frontends use it.

This rationalises the path construction and basename file
operations. The default implementation is POSIX which works for all
frontends except windows, riscos and amiga which have differeing path
separators and rules.

These implementations are significantly more robust than the previous
nine implementations and also do not use unsafe strncpy or buffers
with arbitrary length limits.

These implementations also carry full documentation comments.

1 files changed, 117 insertions, 0 deletions

diff --git a/utils/file.c b/utils/file.c
new file mode 100644
index 000000000..7b0a4677a
--- /dev/null
+++ b/utils/file.c
@@ -0,0 +1,117 @@
+/*
+ * Copyright 2014 vincent Sanders <vince@netsurf-browser.org>
+ *
+ * This file is part of NetSurf, http://www.netsurf-browser.org/
+ *
+ * NetSurf is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * NetSurf is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** \file
+ * Table operations for files with posix compliant path separator.
+ */
+
+#include <stdarg.h>
+#include <string.h>
+
+#include "desktop/gui_factory.h"
+#include "utils/utils.h"
+
+#include "utils/file.h"
+
+/**
+ * Generate a posix path from one or more component elemnts.
+ *
+ * If a string is allocated it must be freed by the caller.
+ *
+ * @param[in,out] str pointer to string pointer if this is NULL enough
+ *                    storage will be allocated for the complete path.
+ * @param[in,out] size The size of the space available if \a str not
+ *                     NULL on input and if not NULL set to the total
+ *                     output length on output.
+ * @param[in] nemb The number of elements.
+ * @param[in] ... The elements of the path as string pointers.
+ * @return NSERROR_OK and the complete path is written to str
+ *         or error code on faliure.
+ */
+static nserror posix_mkpath(char **str, size_t *size, size_t nelm, va_list ap)
+{
+	return vsnstrjoin(str, size, '/', nelm, ap);
+}
+
+/**
+ * Get the basename of a file using posix path handling.
+ *
+ * This gets the last element of a path and returns it.
+ *
+ * @param[in] path The path to extract the name from.
+ * @param[in,out] str Pointer to string pointer if this is NULL enough
+ *                    storage will be allocated for the path element.
+ * @param[in,out] size The size of the space available if \a
+ *                     str not NULL on input and set to the total
+ *                     output length on output.
+ * @return NSERROR_OK and the complete path is written to str
+ *         or error code on faliure.
+ */
+static nserror posix_basename(const char *path, char **str, size_t *size)
+{
+	const char *leafname;
+	char *fname;
+
+	if (path == NULL) {
+		return NSERROR_BAD_PARAMETER;
+	}
+
+	leafname = strrchr(path, '/');
+	if (!leafname) {
+		leafname = path;
+	} else {
+		leafname += 1;
+	}
+
+	fname = strdup(leafname);
+	if (fname == NULL) {
+		return NSERROR_NOMEM;
+	}
+
+	*str = fname;
+	if (size != NULL) {
+		*size = strlen(fname);
+	}
+	return NSERROR_OK;
+}
+
+/* exported interface documented in utils/file.h */
+nserror netsurf_mkpath(char **str, size_t *size, size_t nelm, ...)
+{
+	va_list ap;
+	nserror ret;
+
+	va_start(ap, nelm);
+	if (guit != NULL) {
+		ret = guit->file->mkpath(str, size, nelm, ap);
+	} else {
+		/* default to posix */
+		ret = vsnstrjoin(str, size, '/', nelm, ap);
+	}
+	va_end(ap);
+
+	return ret;
+}
+
+/* default to using the posix file handling */
+static struct gui_file_table file_table = {
+	.mkpath = posix_mkpath,
+	.basename = posix_basename,
+};
+
+struct gui_file_table *default_file_table = &file_table;