Handle escape sequence

tlc.c

@@ -1,31 +1,103 @@
 #include <stdio.h>
-#include <math.h>
 #include <stdlib.h>
-#include <unistd.h>
+#include <time.h>
+#include <math.h>
 
-void rgb(int i, int *r, int *g, int *b)
+enum esc_st {
+	ST_NONE = 0,
+	ST_ESC_BEGIN,
+	ST_ESC_STRING,
+	ST_ESC_CSI,
+	ST_ESC_STRING_TERM,
+	ST_ESC_CSI_TERM,
+	ST_ESC_TERM,
+	NUM_ST
+};
+
+static enum esc_st find_escape_sequences(int c, enum esc_st st)
 {
-    float f = 0.1;
+	if (st == ST_NONE || st == ST_ESC_CSI_TERM) {
-    *r = (int)(sin(f * i + 0) * 127 + 128);
+		if (c == '\033') {
-    *g = (int)(sin(f * i + 2 * M_PI / 3) * 127 + 128);
+			return ST_ESC_BEGIN;
-    *b = (int)(sin(f * i + 4 * M_PI / 3) * 127 + 128);
+		} else {
+			return ST_NONE;
 		}
 
-int main()
+	} else if (st == ST_ESC_BEGIN) {
-{
+		if (c == '[') {
-    if (isatty(fileno(stdin))) {
+			return ST_ESC_CSI;
-        fprintf(stderr, "The command is intended to work with pipes.\n");
+		} else if (c == 'P' || c == ']' || c == 'X' || c == '^' || c == '_') {
-		exit(1);
+			return ST_ESC_STRING;
+		} else {
+			return ST_ESC_TERM;
 		}
 
-    int j = 0;
+	} else if (st == ST_ESC_CSI) {
+		if (0x40 <= c && c <= 0x7e) {
+			return ST_ESC_CSI_TERM;
+		} else {
+			return st;
+		}
+
+	} else if (st == ST_ESC_STRING) {
+		if (c == '\007') {
+			return ST_NONE;
+		} else if (c == '\033') {
+			return ST_ESC_STRING_TERM;
+		} else {
+			return st;
+		}
+
+	} else if (st == ST_ESC_STRING_TERM) {
+		if (c == '\\') {
+			return ST_NONE;
+		} else {
+			return ST_ESC_STRING;
+		}
+
+	} else {
+		return ST_NONE;
+	}
+}
+
+int main(int argc, char** argv)
+{
+	int i = 0, l = 0;
 	int c;
+	srand(time(NULL));
+	double offx = rand() % 300;
+
 	while ((c = getchar()) != EOF) {
-        int r, g, b;
+		int escape_state = find_escape_sequences(c, escape_state);
-        rgb(j, &r, &g, &b);
+		if (escape_state == ST_ESC_CSI_TERM) {
-        printf("\033[38;2;%d;%d;%dm%c\033[0m", r, g, b, c);
+			putchar(c);
-        j++;
 		}
 
+		if (escape_state == ST_NONE || escape_state == ST_ESC_CSI_TERM) {
+			if (c == '\n') {
+				l++;
+				i = 0;
+			} else {
+				if (escape_state == ST_NONE) {
+					i++;
+				}
+
+				float theta = i * 0.23 / 5.0f + l * 0.1 + (offx / RAND_MAX) * M_PI;
+
+				float offset = 0.1;
+				unsigned char r = lrintf((offset + (1.0f - offset) * (0.5f + 0.5f * sin(theta))) * 255.0f);
+				unsigned char g = lrintf((offset + (1.0f - offset) * (0.5f + 0.5f * sin(theta + 2 * M_PI / 3))) * 255.0f);
+				unsigned char b = lrintf((offset + (1.0f - offset) * (0.5f + 0.5f * sin(theta + 4 * M_PI / 3))) * 255.0f);
+
+				printf("\033[38;2;%d;%d;%dm", r, g, b);
+			}
+		}
+
+		if (escape_state != ST_ESC_CSI_TERM) {
+			putchar(c);
+		}
+	}
+
+	printf("\033[0m");
 	return 0;
 }