1 files changed, 56 insertions, 0 deletions
diff --git a/coreutils/cksum.c b/coreutils/cksum.c
new file mode 100644
index 0000000..194ea7d
--- /dev/null
+++ b/coreutils/cksum.c
@@ -0,0 +1,56 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * cksum - calculate the CRC32 checksum of a file
+ *
+ * Copyright (C) 2006 by Rob Sullivan, with ideas from code by Walter Harms
+ * 
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include "busybox.h"
+
+int cksum_main(int argc, char **argv) {
+	
+	uint32_t *crc32_table = bb_crc32_filltable(1);
+
+	FILE *fp;
+	uint32_t crc;
+	long length, filesize;
+	int bytes_read;
+	char *cp;
+	RESERVE_CONFIG_BUFFER(buf, BUFSIZ);
+	int inp_stdin = (argc == optind) ? 1 : 0;
+	
+	do {
+		fp = bb_wfopen_input((inp_stdin) ? bb_msg_standard_input : *++argv);
+			
+		crc = 0;
+		length = 0;
+		
+		while ((bytes_read = fread(buf, 1, BUFSIZ, fp)) > 0) {
+			cp = buf;
+			length += bytes_read;
+			while (bytes_read--)
+				crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ (*cp++)) & 0xffL];
+		}
+		
+		filesize = length;
+		
+		for (; length; length >>= 8)
+			crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ length) & 0xffL];
+		crc ^= 0xffffffffL;
+
+		if (inp_stdin) {
+			printf("%"PRIu32" %li\n", crc, filesize);
+			break;
+		}
+		
+		printf("%"PRIu32" %li %s\n", crc, filesize, *argv);	
+		fclose(fp);
+	} while (*(argv+1));
+	
+	return EXIT_SUCCESS;
+}