initial commit

1 files changed, 271 insertions, 0 deletions

diff --git a/uxd.c b/uxd.c
new file mode 100644
index 0000000..00a2686
--- /dev/null
+++ b/uxd.c
@@ -0,0 +1,271 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+/* output looks like:
+
+       0  1  2  3  4  5  6  7   8  9  A  B  C  D  E  F
+0000: 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  abcdefghijklmnop
+
+...first column will extend to more digits if needed.
+*/
+
+/* UTF-8 spec summary, taken from Wikipedia and elsewhere, kept here
+   for locality of reference.
+
+Codepoints 0-0x7f encode as themselves, one byte each, bit 7 always 0.
+
+0x80 and up are encoded as multiple bytes. The first byte's bit 7 is
+always 1. The top bits determine the byte length of the sequence:
+
+110 - 2 bytes
+1110 - 3 bytes
+11110 - 4 bytes
+
+Continuation (2nd and further bytes) have 10 as the top 2 bits. If
+we get a continuation that's not after a sequence-starter, that's an
+error. If we get a sequence-starter, but the sequence doesn't have
+the correct number of continuation bytes (e.g. 110xxxxx followed by
+anything that isn't 10xxxxxx), that's an error too.
+
+BOM: if the file contains ef bb bf (aka U+FEFF), it should be colorized
+as a special (non-printable).
+If the file begins with ff fe, it's UTF-16 (little endian). If it's
+fe ff, it's UTF-16 big-endian. Probably we should detect these and
+print a warning on stderr.
+*/
+
+/* max UTF-8 sequence length, in bytes */
+#define MAXUTF8 4
+
+/* ANSI color */
+#define BLACK 0 /* don't use */
+#define RED 1
+#define GREEN 2
+#define YELLOW 3
+#define BLUE 4 /* don't use */
+#define PURPLE 5
+#define CYAN 6
+#define WHITE 7 /* don't use */
+
+#define SPECIAL PURPLE
+
+#define BAD_FG BLACK
+#define BAD_BG RED
+
+// const int normal_colors[] = { GREEN, PURPLE, CYAN };
+const int normal_colors[] = { GREEN, YELLOW };
+int cur_normal_color = 0;
+int dump_color;
+
+const char *self;
+FILE *input;
+
+/* these buffers are bigger than they need to be really. */
+char left_buf[4096];
+char right_buf[4096];
+
+#define MAX_DUMP_COLS 16
+int dump_column = 0;
+int filepos = 0;
+
+void usage(void) {
+	printf("Usage: %s <file>\n", self);
+	printf("  With no <file>, or with -, read standard input.\n");
+	exit(0);
+}
+
+void open_input(const int argc, const char *argv1) {
+	if(argc == 1) {
+		input = stdin;
+		return;
+	}
+
+	if(argv1[0] == '-' && argv1[1] != '\0') {
+		usage();
+	}
+
+	if(argc == 2) {
+		if(strcmp(argv1, "-") == 0)
+			input = stdin;
+		else {
+			input = fopen(argv1, "rb");
+			if(!input) {
+				fprintf(stderr, "%s: ", self);
+				perror(argv1);
+				exit(1);
+			}
+		}
+	}
+}
+
+char * const special_symbols[] = {
+	"␀", "␁", "␂", "␃", "␄", "␅", "␆", "␇", "␈", "⇥", "↵", "␋", "␌", "␍", "␎", "␏",
+	"␐", "␑", "␒", "␓", "␔", "␕", "␖", "␗", "␘", "␙", "␚", "␛", "␜", "␝", "␞", "␟",
+	"␣",
+};
+
+char *get_special(unsigned char c) {
+	if(c == 0x7f) return "⌦";
+	if(c <= ' ') return special_symbols[c];
+	return "?"; /* should never happen */
+}
+
+void set_self(const char *argv0) {
+	self = strrchr(argv0, '/');
+
+	if(self)
+		self++;
+	else
+		self = argv0;
+}
+
+void next_normal_color() {
+	cur_normal_color++;
+	cur_normal_color %= (sizeof(normal_colors) / sizeof(int));
+}
+
+void append_color(char *buf, int fgcolor, int bgcolor) {
+	char tmpbuf[100];
+
+	sprintf(tmpbuf, "\x1b[0;3%d", fgcolor);
+	strcat(buf, tmpbuf);
+	if(bgcolor) {
+		sprintf(tmpbuf, ";4%d", bgcolor);
+		strcat(buf, tmpbuf);
+	}
+	sprintf(tmpbuf, "m");
+	strcat(buf, tmpbuf);
+}
+
+void print_line(void) {
+	int spacing = MAX_DUMP_COLS - dump_column;
+	printf("%s", left_buf);
+	while(spacing--) printf("   ");
+	printf(" %s\n", right_buf);
+	left_buf[0] = right_buf[0] = '\0';
+}
+
+void append_color_off(char *buf) {
+	strcat(buf, "\x1b[0m");
+}
+
+void append_right(char *str) {
+	strcat(right_buf, str);
+}
+
+void append_left(unsigned char byte, int fgcolor, int bgcolor) {
+	char tmpbuf[100];
+
+	if(!dump_column)
+		sprintf(left_buf, "%04x: ", filepos);
+
+	append_color(left_buf, fgcolor, bgcolor);
+	sprintf(tmpbuf, "%02x", byte);
+	strcat(left_buf, tmpbuf);
+	append_color_off(left_buf);
+	strcat(left_buf, " ");
+
+	if(dump_column == 7) strcat(left_buf, " ");
+	dump_column++;
+	if(dump_column == MAX_DUMP_COLS) {
+		print_line();
+		dump_column = 0;
+	}
+
+	filepos++;
+}
+
+int dump_utf8_char(void) {
+	unsigned char bytes[] = { 0, 0, 0, 0, 0 };
+	unsigned char *cont_bytes = bytes + 1;
+	char *printable;
+	int bad = 0, special = 0;
+	int c, cont_count, i, fg, bg;
+
+	c = fgetc(input);
+	if(c == EOF)
+		return 0;
+
+	bytes[0] = (unsigned char)c;
+
+	if(c < 0x7f) {
+		cont_count = 0;
+		if(c <= ' ' || c == 0x7f)
+			special = 1;
+	} else if((c & 0xe0) == 0xc0) /* 110xxxxx */
+		cont_count = 1;
+	else if((c & 0xf0) == 0xe0)   /* 1110xxxx */
+		cont_count = 2;
+	else if((c & 0xf8) == 0xf0)   /* 11110xxx */
+		cont_count = 3;
+	else {
+		cont_count = 0;
+		bad = 1;
+	}
+
+	for(i = 0; i < cont_count; i++) {
+		int cb;
+		c = fgetc(input);
+
+		if(c == EOF) {
+			/* EOF in mid-sequence */
+			cont_count = i;
+			bad = 1;
+			break;
+		}
+
+		cb = cont_bytes[i] = (unsigned char)c;
+		if((cb & 0xc0) != 0x80) {
+			/* Expected 10xxxxxx, got something else */
+			cont_count = i;
+			bad = 1;
+			ungetc(cb, input);
+			break;
+		}
+	}
+
+	/* TODO: handle BOM? what about combining diacritics? */
+	if(bad) {
+		fg = BAD_FG;
+		bg = BAD_BG;
+		/* replacement character � is U+FFFD */
+		printable = "�";
+	} else if(special) {
+		fg = SPECIAL;
+		bg = 0;
+		printable = get_special(bytes[0]);
+	} else {
+		fg = normal_colors[cur_normal_color];
+		bg = 0;
+		printable = (char *)bytes;
+		next_normal_color();
+	}
+
+	append_color(right_buf, fg, bg);
+	append_right(printable);
+	append_color_off(right_buf);
+
+	for(i = 0; i <= cont_count; i++) {
+		append_left(bytes[i], fg, bg);
+	}
+
+	return 1;
+}
+
+void dump_file(void) {
+	while(dump_utf8_char())
+		;
+
+	if(dump_column)
+		print_line();
+}
+
+int main(int argc, char **argv) {
+	set_self(argv[0]);
+	open_input(argc, argv[1]);
+	dump_file();
+	fclose(input);
+	return 0;
+}