Start parsing a DEC file.

[cascardo/libreceita.git] / decfile.c

diff --git a/decfile.c b/decfile.c
new file mode 100644 (file)
index 0000000..ebffc9f
--- /dev/null
+++ b/decfile.c
@@ -0,0 +1,118 @@
+/*
+ *  Copyright (C) 2012-2013  Thadeu Lima de Souza Cascardo <cascardo@minaslivre.org>
+ *
+ *  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; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  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, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#define _GNU_SOURCE
+#include "decfile.h"
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <unistd.h>
+
+struct rnet_decfile {
+       char *filename;
+       FILE *file;
+       char **lines;
+       int lines_len;
+};
+
+/*
+ * line should be an allocated buffer given to append_line
+ * this means, free(line) will be called when decfile is released
+ */
+static int append_line(struct rnet_decfile *decfile, char *line)
+{
+       size_t len;
+       char **old_lines;
+       decfile->lines_len += 1;
+       len = sizeof(*decfile->lines) * decfile->lines_len;
+       old_lines = decfile->lines;
+       decfile->lines = realloc(decfile->lines, len);
+       if (!decfile->lines) {
+               decfile->lines = old_lines;
+               goto out;
+       }
+       decfile->lines[decfile->lines_len - 1] = line;
+       return 0;
+out:
+       decfile->lines_len -= 1;
+       return -1;
+}
+
+static void decfile_release_lines(struct rnet_decfile *decfile)
+{
+       int i;
+       for (i = 0; i < decfile->lines_len; i++)
+               free(decfile->lines[i]);
+       free(decfile->lines);
+       decfile->lines = NULL;
+}
+
+static int decfile_parse(struct rnet_decfile *decfile)
+{
+       char *buffer = NULL;
+       size_t len = 0;
+       int r;
+       while ((r = getline(&buffer, &len, decfile->file)) > 0) {
+               r = append_line(decfile, buffer);
+               if (r) {
+                       free(buffer);
+                       goto out;
+               }
+               buffer = NULL;
+               len = 0;
+       }
+       return 0;
+out:
+       decfile_release_lines(decfile);
+       return -1;
+}
+
+struct rnet_decfile * rnet_decfile_open(char *filename)
+{
+       struct rnet_decfile *decfile;
+       decfile = malloc(sizeof(*decfile));
+       if (!decfile)
+               return NULL;
+       decfile->filename = strdup(filename);
+       if (!decfile->filename)
+               goto out_filename;
+       decfile->file = fopen(filename, "r");
+       if (!decfile->file)
+               goto out_file;
+       decfile->lines_len = 0;
+       decfile->lines = NULL;
+       if (decfile_parse(decfile))
+               goto out_parse;
+       return decfile;
+out_parse:
+       fclose(decfile->file);
+out_file:
+       free(decfile->filename);
+out_filename:
+       free(decfile);
+       return NULL;
+}
+
+void rnet_decfile_close(struct rnet_decfile *decfile)
+{
+       decfile_release_lines(decfile);
+       fclose(decfile->file);
+       free(decfile->filename);
+       free(decfile);
+}