Initial revision

src/libmdb/file.c

@@ -0,0 +1,103 @@
+/* MDB Tools - A library for reading MS Access database files
+ * Copyright (C) 2000 Brian Bruns
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include "mdbtools.h"
+
+MDB_HANDLE *mdb_open(char *filename)
+{
+MDB_HANDLE *mdb;
+
+	mdb = mdb_alloc_handle();
+	mdb->filename = (char *) malloc(strlen(filename)+1);
+	strcpy(mdb->filename, filename);
+	mdb->fd = open(filename,O_RDONLY);
+
+	if (mdb->fd==-1) {
+		fprintf(stderr,"Couldn't open file %s\n",filename);
+		return NULL;
+	}
+
+	return mdb;
+}
+
+/* 
+** mdb_read a wrapper for read that bails if anything is wrong 
+*/
+size_t mdb_read_pg(MDB_HANDLE *mdb, unsigned long pg)
+{
+size_t len;
+off_t offset = pg * MDB_PGSIZE;
+struct stat status;
+
+        fstat(mdb->fd, &status);
+        if (status.st_size < offset) { 
+                fprintf(stderr,"offset %lu is beyond EOF\n",offset);
+                return 0;
+        }
+	lseek(mdb->fd, offset, SEEK_SET);
+	len = read(mdb->fd,mdb->pg_buf,MDB_PGSIZE);
+	if (len==-1) {
+		perror("read");
+		return 0;
+	}
+	else if (len<MDB_PGSIZE) {
+		fprintf(stderr,"EOF reached.\n");
+		return 0;
+	}
+	return len;
+}
+int mdb_get_int16(MDB_HANDLE *mdb, int offset)
+{
+unsigned char *c;
+int           i;
+
+	if (offset < 0 || offset+2 > MDB_PGSIZE) return -1;
+	c = &mdb->pg_buf[offset];
+	i = c[1]*256+c[0];
+
+	mdb->cur_pos+=2;
+	return i;
+	
+}
+long mdb_get_int32(MDB_HANDLE *mdb, int offset)
+{
+long l;
+unsigned char *c;
+
+	if (offset <0 || offset+4 > MDB_PGSIZE) return -1;
+	c = &mdb->pg_buf[offset];
+	l =c[3]; l<<=8;
+	l+=c[2]; l<<=8;
+	l+=c[1]; l<<=8;
+	l+=c[0];
+
+	mdb->cur_pos+=4;
+	return l;
+}
+int mdb_set_pos(MDB_HANDLE *mdb, int pos)
+{
+	if (pos<0 || pos >= MDB_PGSIZE) return 0;
+
+	mdb->cur_pos=pos;
+	return pos;
+}
+int mdb_get_pos(MDB_HANDLE *mdb)
+{
+	return mdb->cur_pos;
+}