1 files changed, 98 insertions, 0 deletions
diff --git a/hexdump.c b/hexdump.c
new file mode 100644
index 0000000..552e4c6
--- /dev/null
+++ b/hexdump.c
@@ -0,0 +1,98 @@
+/* See LICENSE file for copyright and license details. */
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <ctype.h>
+
+#include "util.h"
+
+static void
+usage(void)
+{
+	eprintf("usage: %s [-C] [file ...]\n", argv0);
+}
+
+#define BYTES_PER_LINE 16
+
+int
+main(int argc, char *argv[])
+{
+	int fd;
+	char c;
+	int nread;
+	int pos;
+	int lastpos;
+	int i;
+	char buf[BYTES_PER_LINE];
+
+	ARGBEGIN {
+	case 'v':
+		break;
+	case 'C':
+		break;
+	default:
+		usage();
+	} ARGEND
+
+	if (argc < 1 && isatty(STDIN_FILENO)) {
+		usage();
+	}
+
+	if (isatty(STDIN_FILENO)) {
+		if ((fd = open(*argv, O_RDONLY)) < 0) {
+			weprintf("open %s:", *argv);
+			return 0;
+			
+		}
+	} else {
+		fd = STDIN_FILENO;
+	}
+
+	lastpos = 0;
+	pos = 0;
+	while ((nread=read(fd, &c, 1)) >= 0) {
+		if (nread > 0) {
+			if (pos % BYTES_PER_LINE == 0) {
+				printf("%08x ", pos);
+			}
+			printf(" %02x", c & 0xFF );
+			buf[pos%BYTES_PER_LINE] = c;
+			pos++;
+		} else {
+			if (lastpos == 0) {
+				lastpos = pos;
+			}
+			printf("   ");
+			pos++;
+		}
+		if (pos % BYTES_PER_LINE == BYTES_PER_LINE/2) {
+			printf(" ");
+		}
+		if (pos % BYTES_PER_LINE == 0) {
+			printf("  |");
+			if (nread == 0) {
+				pos = lastpos;
+			}
+			for (i = 0; i <= (pos+BYTES_PER_LINE-1) % BYTES_PER_LINE; i++) {
+				if (isprint(buf[i]) ) {
+					putchar(buf[i]);
+				} else {
+					putchar('.');
+				}
+			}
+			puts("|");
+			if (nread == 0) {
+				goto END;
+			}
+		}
+	}
+END:
+	printf("%08x\n", pos);
+
+
+	if (fd > STDERR_FILENO) {
+		close(fd);
+	}
+	
+	return 0;
+}