--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/libphysfs/archiver_grp.c	Fri Feb 22 05:43:56 2013 +0100
@@ -0,0 +1,110 @@
+/*
+ * GRP support routines for PhysicsFS.
+ *
+ * This driver handles BUILD engine archives ("groupfiles"). This format
+ *  (but not this driver) was put together by Ken Silverman.
+ *
+ * The format is simple enough. In Ken's words:
+ *
+ *    What's the .GRP file format?
+ *
+ *     The ".grp" file format is just a collection of a lot of files stored
+ *     into 1 big one. I tried to make the format as simple as possible: The
+ *     first 12 bytes contains my name, "KenSilverman". The next 4 bytes is
+ *     the number of files that were compacted into the group file. Then for
+ *     each file, there is a 16 byte structure, where the first 12 bytes are
+ *     the filename, and the last 4 bytes are the file's size. The rest of
+ *     the group file is just the raw data packed one after the other in the
+ *     same order as the list of files.
+ *
+ * (That info is from http://www.advsys.net/ken/build.htm ...)
+ *
+ * Please see the file LICENSE.txt in the source's root directory.
+ *
+ *  This file written by Ryan C. Gordon.
+ */
+
+#define __PHYSICSFS_INTERNAL__
+#include "physfs_internal.h"
+
+#if PHYSFS_SUPPORTS_GRP
+
+static UNPKentry *grpLoadEntries(PHYSFS_Io *io, PHYSFS_uint32 fileCount)
+{
+    PHYSFS_uint32 location = 16;  /* sizeof sig. */
+    UNPKentry *entries = NULL;
+    UNPKentry *entry = NULL;
+    char *ptr = NULL;
+
+    entries = (UNPKentry *) allocator.Malloc(sizeof (UNPKentry) * fileCount);
+    BAIL_IF_MACRO(entries == NULL, PHYSFS_ERR_OUT_OF_MEMORY, NULL);
+
+    location += (16 * fileCount);
+
+    for (entry = entries; fileCount > 0; fileCount--, entry++)
+    {
+        GOTO_IF_MACRO(!__PHYSFS_readAll(io, &entry->name, 12), ERRPASS, failed);
+        GOTO_IF_MACRO(!__PHYSFS_readAll(io, &entry->size, 4), ERRPASS, failed);
+        entry->name[12] = '\0';  /* name isn't null-terminated in file. */
+        if ((ptr = strchr(entry->name, ' ')) != NULL)
+            *ptr = '\0';  /* trim extra spaces. */
+
+        entry->size = PHYSFS_swapULE32(entry->size);
+        entry->startPos = location;
+        location += entry->size;
+    } /* for */
+
+    return entries;
+
+failed:
+    allocator.Free(entries);
+    return NULL;
+} /* grpLoadEntries */
+
+
+static void *GRP_openArchive(PHYSFS_Io *io, const char *name, int forWriting)
+{
+    PHYSFS_uint8 buf[12];
+    PHYSFS_uint32 count = 0;
+    UNPKentry *entries = NULL;
+
+    assert(io != NULL);  /* shouldn't ever happen. */
+
+    BAIL_IF_MACRO(forWriting, PHYSFS_ERR_READ_ONLY, NULL);
+
+    BAIL_IF_MACRO(!__PHYSFS_readAll(io, buf, sizeof (buf)), ERRPASS, NULL);
+    if (memcmp(buf, "KenSilverman", sizeof (buf)) != 0)
+        BAIL_MACRO(PHYSFS_ERR_UNSUPPORTED, NULL);
+
+    BAIL_IF_MACRO(!__PHYSFS_readAll(io, &count, sizeof(count)), ERRPASS, NULL);
+    count = PHYSFS_swapULE32(count);
+
+    entries = grpLoadEntries(io, count);
+    BAIL_IF_MACRO(!entries, ERRPASS, NULL);
+    return UNPK_openArchive(io, entries, count);
+} /* GRP_openArchive */
+
+
+const PHYSFS_Archiver __PHYSFS_Archiver_GRP =
+{
+    {
+        "GRP",
+        "Build engine Groupfile format",
+        "Ryan C. Gordon <icculus@icculus.org>",
+        "http://icculus.org/physfs/",
+    },
+    GRP_openArchive,        /* openArchive() method    */
+    UNPK_enumerateFiles,    /* enumerateFiles() method */
+    UNPK_openRead,          /* openRead() method       */
+    UNPK_openWrite,         /* openWrite() method      */
+    UNPK_openAppend,        /* openAppend() method     */
+    UNPK_remove,            /* remove() method         */
+    UNPK_mkdir,             /* mkdir() method          */
+    UNPK_closeArchive,      /* closeArchive() method   */
+    UNPK_stat               /* stat() method           */
+};
+
+#endif  /* defined PHYSFS_SUPPORTS_GRP */
+
+/* end of grp.c ... */
+