hex

commit 37dbb85cda6f5a92b89c22bb410943aa011a5852
Author: Louis Burda <quent.burda@gmail.com>
Date:   Fri,  5 Aug 2022 18:09:15 +0200

Simple hex manipulation tools

Diffstat:
A
.gitignore
 | 
3
+++
A
Makefile
 | 
12
++++++++++++
A
hex.c
 | 
44
++++++++++++++++++++++++++++++++++++++++++++
A
hexv.c
 | 
113
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A
unhex.c
 | 
63
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

5 files changed, 235 insertions(+), 0 deletions(-)
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1,3 @@
+hex
+unhex
+hexv
diff --git a/Makefile b/Makefile
@@ -0,0 +1,12 @@
+.PHONY: all clean
+
+all: hex hexv unhex
+
+clean:
+	rm -f hex hexv unhex
+
+hex: hex.c
+
+hexv: hexv.c
+
+unhex: unhex.c
diff --git a/hex.c b/hex.c
@@ -0,0 +1,44 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+const char *hex = "0123456789abcdef";
+
+void
+tohex(int fd)
+{
+	char buf[4096];
+	ssize_t i, nread;
+
+	while (1) {
+		nread = read(fd, buf, sizeof(buf));
+		if (nread <= 0) return;
+
+		for (i = 0; i < nread; i++) {
+			putchar(hex[(buf[i] >> 4) & 0xf]);
+			putchar(hex[(buf[i] >> 0) & 0xf]);
+		}
+	}
+}
+
+int
+main(int argc, const char **argv)
+{
+	int i, fd;
+
+	if (argc > 1) {
+		for (i = 1; i < argc; i++) {
+			fd = open(argv[i], O_RDONLY);
+			if (fd < 0) {
+				fprintf(stderr, "Could not open file: %s\n",
+					argv[i]);
+				continue;
+			}
+			tohex(fd);
+			close(fd);
+		}
+	} else {
+		tohex(0);
+	}
+}
diff --git a/hexv.c b/hexv.c
@@ -0,0 +1,113 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+static const char hex[] = "0123456789abcdef";
+
+static int color = 0;
+static int gradient[256] = {
+	[0] = 241,
+	[1 ... 31] = 242,
+	[32 ... 63] = 244,
+	[64 ... 95] = 246,
+	[96 ... 127] = 247,
+	[128 ... 159] = 248,
+	[160 ... 191] = 250,
+	[192 ... 223] = 252,
+	[224 ... 253] = 254,
+	[255] = 255,
+};
+
+void
+colorhex(uint8_t c)
+{
+	if (gradient[c] != color) {
+		color = gradient[c];
+		printf("\x1b[38;5;%im", color);
+	}
+	putchar(hex[(c >> 4) & 0xf]);
+	putchar(hex[(c >> 0) & 0xf]);
+}
+
+void
+printrow(char *row, size_t pos, size_t len)
+{
+	size_t i;
+
+	printf("%08lx: ", pos);
+	for (i = 0; i < 16; i++) {
+		if (i < len) {
+			colorhex(row[i]);
+		} else {
+			printf("  ");
+		}
+		if ((i + 1) % 2 == 0)
+			putchar(' ');
+	}
+	if (color != 0)
+		printf("\x1b[0m");
+	color = 0;
+
+	printf("  ");
+
+	for (i = 0; i < 16; i++) {
+		if (i < len) {
+			if (row[i] >= 0x20 && row[i] <= 126) {
+				putchar(row[i]);
+			} else {
+				putchar('.');
+			}
+		} else {
+			putchar(' ');
+		}
+	}
+	printf("\n");
+}
+
+void
+tohex(int fd)
+{
+	size_t pos, i, k;
+	ssize_t nread;
+	char buf[4096];
+	char row[16];
+
+	pos = 0;
+	while (1) {
+		nread = read(fd, buf, sizeof(buf));
+		if (nread <= 0) break;
+
+		for (i = 0; i < nread; i++, pos++) {
+			row[pos % 16] = buf[i];
+			if ((pos + 1) % 16 == 0)
+				printrow(row, pos & ~15UL, 16);
+		}
+	}
+
+	if (pos % 16 != 0)
+		printrow(row, pos & ~15UL, pos % 16);
+}
+
+int
+main(int argc, const char **argv)
+{
+	int i, fd;
+
+	if (argc > 1) {
+		for (i = 1; i < argc; i++) {
+			if (i > 1) printf("\n");
+			fd = open(argv[i], O_RDONLY);
+			if (fd < 0) {
+				fprintf(stderr, "Could not open file: %s\n",
+					argv[i]);
+				continue;
+			}
+			tohex(fd);
+			close(fd);
+		}
+	} else {
+		tohex(0);
+	}
+}
diff --git a/unhex.c b/unhex.c
@@ -0,0 +1,63 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+const char *hex = "0123456789abcdef";
+
+char
+hex2nib(char c)
+{
+	if (c >= '0' && c <= '9')
+		return c - '0';
+	else if (c >= 'a' && c <= 'f')
+		return c - 'a' + 10;
+	else if (c >= 'A' && c <= 'F')
+		return c - 'A' + 10;
+
+	fprintf(stderr, "Invalid hex char\n");
+	exit(1);
+}
+
+void
+fromhex(int fd)
+{
+	ssize_t pos, i, nread;
+	char buf[4096], nib;
+
+	pos = 0;
+	while (1) {
+		nread = read(fd, buf, sizeof(buf));
+		if (nread <= 0) return;
+
+		for (i = 0; i < nread; i++, pos++) {
+			if (buf[i] == '\n') continue;
+			if (pos % 2 == 0) {
+				nib = hex2nib(buf[i]);
+			} else {
+				putchar((nib << 4) | hex2nib(buf[i]));
+			}
+		}
+	}
+}
+
+int
+main(int argc, const char **argv)
+{
+	int i, fd;
+
+	if (argc > 1) {
+		for (i = 1; i < argc; i++) {
+			fd = open(argv[i], O_RDONLY);
+			if (fd < 0) {
+				fprintf(stderr, "Could not open file: %s\n",
+					argv[i]);
+				continue;
+			}
+			fromhex(fd);
+			close(fd);
+		}
+	} else {
+		fromhex(0);
+	}
+}