implement -m (mono).

3 files changed, 100 insertions, 43 deletions

diff --git a/uxd.1 b/uxd.1
index bd812d8..306b5a2 100644
--- a/uxd.1
+++ b/uxd.1
@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "UXD" 1 "2024-12-15" "0.1.0" "Urchlay's Utilities"
+.TH "UXD" 1 "2024-12-16" "0.1.0" "Urchlay's Utilities"
 .SH NAME
 uxd \- UTF-8 hex dumper
 .SH SYNOPSIS
@@ -89,8 +89,8 @@ will be dumped.
 .B  \-m
 Monochrome mode. Uses underline, bold, reverse video instead of color.
 Use this if you have trouble distinguishing the colors, or if they
-look too much like angry fruit salad.
-NOT IMPLEMENTED YET.
+look too much like angry fruit salad. Disables prior \fB\-b\fP, \fB\-c\fP
+options.
 .TP
 .B  \-n
 Ignore \fBUXD_OPTS\fP environment variable. This option should not be
@@ -118,7 +118,7 @@ position after seeking. \fB\-S 100\fP is the same as \fB\-s 100 \-o \-100\fP\&.
 Works with negative \fIpos\fP, too.
 .TP
 .B  \-u
-Use uppercase hex digits A\-F. Default is lowercase.
+Use uppercase hex digits \fIA\-F\fP\&. Default is lowercase.
 .TP
 .B  \-v\fP,\fB  \-\-version
 Print version number and exit.
@@ -266,7 +266,8 @@ any files other than standard output. There\(aqs no config file.
 .TP
 .B \fBUXD_OPTS\fP
 If this is set, its value is treated as a set of options, which
-get applied before any command\-line options.
+get applied before any command\-line options (unless the command\-line
+options inclue \fB\-n\fP).
 .TP
 .B \fBNO_COLOR\fP
 If this is set (to any value), \fBuxd\fP runs in monochrome mode, just
diff --git a/uxd.c b/uxd.c
index 93368a1..22a25f3 100644
--- a/uxd.c
+++ b/uxd.c
@@ -65,9 +65,13 @@ extern int optind;
 #define BAD_FG BLACK
 #define BAD_BG bad_color
 
+#define HL_NORMAL 0
+#define HL_NORM_INV 1
+#define HL_SPECIAL 2
+#define HL_BAD 3
+
 int normal_colors[] = { GREEN, YELLOW };
-int cur_normal_color = 0;
-int dump_color;
+int cur_normal_hilite = 1;
 int bad_color = RED;
 int special_color = SPECIAL;
 
@@ -305,13 +309,33 @@ void print_line(void) {
 	dump_column = 0;
 }
 
-void next_normal_color() {
-	cur_normal_color++;
-	cur_normal_color %= (sizeof(normal_colors) / sizeof(int));
+void next_normal_hilite() {
+	cur_normal_hilite = !cur_normal_hilite;
 }
 
-void append_color(char *buf, int fgcolor, int bgcolor) {
+void append_color(char *buf, int hl_type) {
 	char tmpbuf[100];
+	int fgcolor, bgcolor;
+
+	switch(hl_type) {
+		case HL_NORMAL:
+			fgcolor = normal_colors[cur_normal_hilite];
+			bgcolor = 0;
+			break;
+		case HL_NORM_INV:
+			fgcolor = 0;
+			bgcolor = normal_colors[cur_normal_hilite];
+			break;
+		case HL_SPECIAL:
+			fgcolor = special_color;
+			bgcolor = 0;
+			break;
+		default:
+		case HL_BAD:
+			fgcolor = BAD_FG;
+			bgcolor = bad_color;
+			break;
+	}
 
 	sprintf(tmpbuf, "\x1b[%d;3%d", bold, fgcolor);
 	strcat(buf, tmpbuf);
@@ -323,7 +347,36 @@ void append_color(char *buf, int fgcolor, int bgcolor) {
 	strcat(buf, tmpbuf);
 }
 
-void append_color_off(char *buf) {
+void append_mono(char *buf, int hl_type) {
+	char tmpbuf[100];
+	int code;
+
+	switch(hl_type) {
+		case HL_NORMAL:
+		case HL_NORM_INV:
+			code = cur_normal_hilite ? 4 : 0; /* underline : normal */
+			break;
+		case HL_SPECIAL:
+			code = 1; /* bold */
+			break;
+		default:
+		case HL_BAD:
+			code = 7; /* reverse video */
+			break;
+	}
+
+	sprintf(tmpbuf, "\x1b[%dm", code);
+	strcat(buf, tmpbuf);
+}
+
+void append_hilite(char *buf, int hl_type) {
+	if(mono)
+		append_mono(buf, hl_type);
+	else
+		append_color(buf, hl_type);
+}
+
+void append_hilite_off(char *buf) {
 	strcat(buf, "\x1b[0m");
 }
 
@@ -331,13 +384,13 @@ void append_right(char *str) {
 	strcat(right_buf, str);
 }
 
-void append_left(unsigned char byte, int dash, int fgcolor, int bgcolor) {
+void append_left(unsigned char byte, int dash, int hl_type) {
 	char tmpbuf[100];
 
 	if(!dump_column)
 		sprintf(left_buf, hex_word_fmt, filepos + display_offset);
 
-	append_color(left_buf, fgcolor, bgcolor);
+	append_hilite(left_buf, hl_type);
 	sprintf(tmpbuf, hex_byte_fmt, byte);
 	strcat(left_buf, tmpbuf);
 
@@ -347,9 +400,9 @@ void append_left(unsigned char byte, int dash, int fgcolor, int bgcolor) {
 		strcat(left_buf, "-");
 		if(dump_column == (MAX_DUMP_COLS / 2))
 			strcat(left_buf, "-");
-		append_color_off(left_buf);
+		append_hilite_off(left_buf);
 	} else {
-		append_color_off(left_buf);
+		append_hilite_off(left_buf);
 		strcat(left_buf, " ");
 		if(dump_column == (MAX_DUMP_COLS / 2))
 			strcat(left_buf, " ");
@@ -397,8 +450,8 @@ 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;
+	int bad = 0, special = 0, hl_type;
+	int c, cont_count, i;
 	static int byte0;
 
 	c = fgetc(input);
@@ -415,28 +468,33 @@ int dump_utf8_char(void) {
 		check_utf16(byte0, c);
 	}
 
+	/* look at 1st byte to find out how long the sequence is */
 	if(c < 0x7f) {
 		ascii_count++;
 		cont_count = 0;
 		if(c <= ' ' || c == 0x7f)
 			special = 1;
-	} else if((c & 0xe0) == 0xc0) /* 110xxxxx */
+	} else if((c & 0xe0) == 0xc0) {   /* 110xxxxx */
 		cont_count = 1;
-	else if((c & 0xf0) == 0xe0)   /* 1110xxxx */
+	} else if((c & 0xf0) == 0xe0) {   /* 1110xxxx */
 		cont_count = 2;
-	else if((c & 0xf8) == 0xf0)   /* 11110xxx */
+	} else if((c & 0xf8) == 0xf0) {   /* 11110xxx */
 		cont_count = 3;
-	else {
+	} else {
+		/* high bit set, but not a valid sequence-starter */
 		cont_count = 0;
 		bad = 1;
 	}
 
+	/* read and validate the continuation bytes, if any */
 	for(i = 0; i < cont_count; i++) {
 		int cb;
 		c = fgetc(input);
 
 		if(c == EOF) {
-			/* EOF in mid-sequence */
+			/* EOF in mid-sequence. Don't return 0 here, since we still
+			   have to dump the partial sequence. The next call will
+			   give us EOF again. */
 			cont_count = i;
 			bad = 1;
 			break;
@@ -465,36 +523,33 @@ int dump_utf8_char(void) {
 			multi_count++;
 	}
 
+	/* decide how to highlight the current character */
 	if(bad) {
-		fg = BAD_FG;
-		bg = BAD_BG;
+		hl_type = HL_BAD;
 		/* replacement character � is U+FFFD */
 		printable = "�";
 	} else if(special) {
-		fg = special_color;
-		bg = 0;
+		hl_type = HL_SPECIAL;
 		printable = get_special(bytes[0]);
 	} else if(cont_count == 2 && is_bom(bytes)) {
-		fg = special_color;
-		bg = 0;
+		hl_type = HL_SPECIAL;
 		printable = "B";
 	} else {
-		fg = normal_colors[cur_normal_color];
-		bg = 0;
+		hl_type = HL_NORMAL;
 		printable = (char *)bytes;
-		next_normal_color();
+		next_normal_hilite();
 	}
 
-	append_color(right_buf, fg, bg);
+	/* human-readable (right) column: */
+	append_hilite(right_buf, hl_type);
 	append_right(printable);
-	append_color_off(right_buf);
-
-	if(hilite_multi && cont_count) {
-		c = bg; bg = fg; fg = c;
-	}
+	append_hilite_off(right_buf);
 
+	/* hex columns: */
+	if(hilite_multi && cont_count)
+		hl_type = HL_NORM_INV;
 	for(i = 0; i <= cont_count; i++) {
-		append_left(bytes[i], (i != cont_count), fg, bg);
+		append_left(bytes[i], (i != cont_count), hl_type);
 	}
 
 	return 1;
diff --git a/uxd.rst b/uxd.rst
index de5cc86..ed487ae 100644
--- a/uxd.rst
+++ b/uxd.rst
@@ -78,8 +78,8 @@ by itself.
 -m
   Monochrome mode. Uses underline, bold, reverse video instead of color.
   Use this if you have trouble distinguishing the colors, or if they
-  look too much like angry fruit salad.
-  NOT IMPLEMENTED YET.
+  look too much like angry fruit salad. Disables prior **-b**, **-c**
+  options.
 
 -n
   Ignore **UXD_OPTS** environment variable. This option should not be
@@ -107,7 +107,7 @@ by itself.
   Works with negative *pos*, too.
 
 -u
-  Use uppercase hex digits A-F. Default is lowercase.
+  Use uppercase hex digits *A-F*. Default is lowercase.
 
 -v, --version
   Print version number and exit.
@@ -251,7 +251,8 @@ ENVIRONMENT
 
 **UXD_OPTS**
   If this is set, its value is treated as a set of options, which
-  get applied before any command-line options.
+  get applied before any command-line options (unless the command-line
+  options inclue **-n**).
 
 **NO_COLOR**
   If this is set (to any value), **uxd** runs in monochrome mode, just