Restructure files

filereader: file operation, reading files, reading .obj
parser: parses a string representing obj structure, converting
        to HE_obj
print: various helper functions for printing the structures

filereader.c

@@ -0,0 +1,96 @@
+/*
+ * Copyright 2011-2014 hasufell
+ *
+ * This file is part of a hasufell project.
+ *
+ * This program 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 only.
+ *
+ * This program 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/>.
+ */
+
+#include "err.h"
+#include "filereader.h"
+#include "parser.h"
+#include "types.h"
+
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+
+/**
+ * Read an obj file and return a HE_obj
+ * if parsing worked.
+ *
+ * @param filename file to open
+ * @return the HE_obj or NULL for failure
+ */
+HE_obj *read_obj_file(char const * const filename)
+{
+	char *string = NULL; /* file content */
+	HE_obj *obj = NULL;
+
+	/* read the whole file into string */
+	string = read_file(filename);
+	if (!filename || !*filename || !string || !*string)
+		return NULL;
+
+	obj = parse_obj(string);
+	free(string);
+	return obj;
+}
+
+/**
+ * Reads a file and returns a newly allocated string.
+ *
+ * @param filename file to open
+ * @return newly allocated string, must be freed by the caller
+ */
+char *read_file(char const * const filename)
+{
+	char buf[STD_FILE_BUF],
+		 *string = NULL;
+	int objfile = 0;
+	size_t str_size = 0;
+	ssize_t n;
+
+	objfile = open(filename, O_RDONLY);
+
+	if (objfile) {
+		/* read and copy chunks */
+		while ((n = read(objfile, buf, STD_FILE_BUF)) > 0) {
+			char *tmp_ptr = NULL;
+
+			str_size += n; /* count total bytes read */
+
+			tmp_ptr = (char*) realloc( /* allocate correct size */
+					string, /* pointer to realloc */
+					str_size /* total bytes read */
+					+ 1); /* space for trailing NULL byte */
+			CHECK_PTR_VAL(tmp_ptr);
+			string = tmp_ptr;
+
+			/* append buffer to string */
+			memcpy(string + (str_size - n), buf, n);
+		}
+		/* add trailing NULL byte */
+		string[str_size] = '\0';
+
+		close(objfile);
+
+		return string;
+	} else {
+		return NULL;
+	}
+}