From b8a86a6c988386207567cba8eafdf352b468f426 Mon Sep 17 00:00:00 2001
From: Alan Cox <alan@linux.intel.com>
Date: Mon, 29 Dec 2014 22:31:59 +0000
Subject: [PATCH] utils: Add sum

---
 Applications/util/Makefile |   1 +
 Applications/util/sum.c    | 114 +++++++++++++++++++++++++++++++++++++
 2 files changed, 115 insertions(+)
 create mode 100644 Applications/util/sum.c

diff --git a/Applications/util/Makefile b/Applications/util/Makefile
index 95b634b7..4f2d6729 100644
--- a/Applications/util/Makefile
+++ b/Applications/util/Makefile
@@ -64,6 +64,7 @@ SRCS  = banner.c \
 	rmdir.c \
 	sleep.c \
 	ssh.c \
+	sum.c \
 	su.c \
 	sync.c \
 	termcap.c \
diff --git a/Applications/util/sum.c b/Applications/util/sum.c
new file mode 100644
index 00000000..99e32fc6
--- /dev/null
+++ b/Applications/util/sum.c
@@ -0,0 +1,114 @@
+/* sum - checksum a file		Author: Martin C. Atkins */
+
+/*
+ *	This program was written by:
+ *		Martin C. Atkins,
+ *		University of York,
+ *		Heslington,
+ *		York. Y01 5DD
+ *		England
+ *	and is released into the public domain, on the condition
+ *	that this comment is always included without alteration.
+ */
+
+#include <sys/types.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+
+#define BUFFER_SIZE (512)
+
+int rc = 0;
+
+char *defargv[] = {"-", 0};
+
+void error(const char *s, const char *f);
+void sum(int fd, const char *fname);
+void putd(int number, int fw, int zeros);
+
+int main(int argc, char *argv[])
+{
+  register int fd;
+
+  if (*++argv == 0) argv = defargv;
+  for (; *argv; argv++) {
+	if (argv[0][0] == '-' && argv[0][1] == '\0')
+		fd = 0;
+	else
+		fd = open(*argv, O_RDONLY);
+
+	if (fd == -1) {
+		error("can't open ", *argv);
+		rc = 1;
+		continue;
+	}
+	sum(fd, (argc > 2) ? *argv : (char *) 0);
+	if (fd != 0) close(fd);
+  }
+  return(rc);
+}
+
+void error(const char *s, const char *f)
+{
+
+  write(STDERR_FILENO,"sum: ", 5);
+  write(STDERR_FILENO,s, strlen(s));
+
+  if (f) write(STDERR_FILENO, f, strlen(f));
+  write(STDERR_FILENO, "\n", 1);
+}
+
+void sum(int fd, const char *fname)
+{
+  char buf[BUFFER_SIZE];
+  register int i, n;
+  long size = 0;
+  unsigned crc = 0;
+  unsigned tmp, blks;
+
+  while ((n = read(fd, buf, BUFFER_SIZE)) > 0) {
+	for (i = 0; i < n; i++) {
+		crc = (crc >> 1) + ((crc & 1) ? 0x8000 : 0);
+		tmp = buf[i] & 0377;
+		crc += tmp;
+		crc &= 0xffff;
+		size++;
+	}
+  }
+
+  if (n < 0) {
+	if (fname)
+		error("read error on ", fname);
+	else
+		error("read error", (char *) 0);
+	rc = 1;
+	return;
+  }
+  putd(crc, 5, 1);
+  blks = (size + (long) BUFFER_SIZE - 1L) / (long) BUFFER_SIZE;
+  putd(blks, 6, 0);
+  if (fname) printf(" %s", fname);
+  printf("\n");
+}
+
+void putd(int number, int fw, int zeros)
+{
+/* Put a decimal number, in a field width, to stdout. */
+
+  char buf[10];
+  int n;
+  unsigned num;
+
+  num = (unsigned) number;
+  for (n = 0; n < fw; n++) {
+	if (num || n == 0) {
+		buf[fw - n - 1] = '0' + num % 10;
+		num /= 10;
+	} else
+		buf[fw - n - 1] = zeros ? '0' : ' ';
+  }
+  buf[fw] = 0;
+  printf("%s", buf);
+}
-- 
2.34.1