beginnings of the new pak util

tools/pak/pakfile.c

@@ -0,0 +1,93 @@
+#include <limits.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+/*
+	Structs for pack files on disk
+*/
+
+#define PAK_PATH_LENGTH
+
+typedef struct {
+	char        name[PAK_PATH_LENGTH];
+	int         filepos, filelen;
+} dpackfile_t;
+
+typedef struct {
+	char        id[4];
+	int         dirofs;
+	int         dirlen;
+} dpackheader_t;
+
+#define MAX_FILES_IN_PACK   2048
+
+/*
+	In-memory pack file structs
+*/
+
+typedef struct {
+	char        name[PAK_PATH_LENGTH];
+	int         filepos, filelen;
+} packfile_t;
+
+typedef struct pack_s {
+	char        filename[MAX_PATH];
+	FILE       *handle;
+	int         numfiles;
+	packfile_t *files;
+} pack_t;
+
+pack_t *
+new_pack (const char *name)
+{
+	pack_t *pack = calloc (sizeof (*pack), 1);
+
+	if (!pack)
+		return 0;
+	strncpy (pack->filename, name, sizeof (pack->filename));
+	pack->filename[sizeof (pack->filename) - 1] = 0;
+	return pack;
+}
+
+void
+del_pack (pack_t *pack)
+{
+	if (pack->files)
+		free (pack->files);
+	if (pack->handle)
+		fclose (pack->handle);
+	free (pack);
+}
+
+pack_t *
+open_pack (const char *name)
+{
+	dpackheader_t header;
+	pack_t *pack = new_pack (name);
+
+	if (!pack)
+		return 0;
+	pack->handle = fopen (name, "rb");
+	if (!pack->handle) {
+		goto error;
+	}
+	if (fread (&header, sizeof (header), 1, pack->handle) != sizeof (header)) {
+		fprintf (stderr, "%s: not a pack file", name);
+		goto error;
+	}
+	if (strncmp (header.id, "PACK", 4)) {
+		fprintf (stderr, "%s: not a pack file", name);
+		goto error;
+	}
+	pack->numfiles = header.dirlen / sizeof (dpackfile_t);
+	if (pack->numfiles > MAX_FILES_IN_PACK) {
+		fprintf (stderr, "%s: too many files in pack: %d", name, pack->numfiles);
+		goto error;
+	}
+	pack->files = malloc (numpackfiles * sizeof (packfile_t));
+	if (!
+error:
+	del_pack (pack);
+	return 0;
+}