nyancat

commit 40f1336b51cb6804cd3981eda56354317a973258
parent c2c783fc3676b448f5555188501d5fa428c5b476
Author: Santtu Lakkala <inz@inz.fi>
Date:   Mon, 20 Jul 2020 17:10:52 +0300

Add option to bash-escape color codes

Bash needs invisible characters to be escaped with \[ \] in prompt, add
option to output those.

Diffstat:
M
README.md
 | 
4
++++
M
nyancat.c
 | 
45
++++++++++++++++++++++++++++++++++-----------

2 files changed, 38 insertions(+), 11 deletions(-)
diff --git a/README.md b/README.md
@@ -87,3 +87,7 @@ $ for i in `seq 1 3`; do lorem -s 10; echo; echo; done | par -w 60 | nyancat -1
 officia quam sed. Vel nulla odio voluptates beatae et.
 
 ```
+```ansi
+$ PROMPT_COMMAND='PS1="$(echo -n "$USER@$HOSTNAME:${PWD/#$HOME/\~}\$ "|nyancat -vb)"'
+user@host:~/nyancat$ 
+```
diff --git a/nyancat.c b/nyancat.c
@@ -40,7 +40,8 @@ struct lolcat {
 	int h;
 	int sx;
 	int sy;
-	int transpose;
+	bool transpose;
+	bool bash_escape;
 	uint32_t fg;
 	uint32_t bg;
 	bool bg_set;
@@ -442,18 +443,23 @@ static void _lc_colorize(struct lolcat *lc, const char *u8_char, size_t len)
 	}
 
 	if (lc->mode == INDEXED16)
-		bw += sprintf(bw, "3%dm%.*s",
-			      col, (int)len, u8_char);
+		bw += sprintf(bw, "3%dm",
+			      col);
 	else if (lc->mode == INDEXED256)
-		bw += sprintf(bw, "38;5;%dm%.*s",
-			      col, (int)len, u8_char);
+		bw += sprintf(bw, "38;5;%dm",
+			      col);
 	else
-		bw += sprintf(bw, "38;2;%d;%d;%dm%.*s",
+		bw += sprintf(bw, "38;2;%d;%d;%dm",
 			      col >> 16,
 			      (col >> 8) & 255,
-			      col & 255, (int)len, u8_char);
+			      col & 255);
 
+	if (lc->bash_escape)
+		lc->write("\\[", 2, lc->write_data);
 	lc->write(buffer, bw - buffer, lc->write_data);
+	if (lc->bash_escape)
+		lc->write("\\]", 2, lc->write_data);
+	lc->write(u8_char, len, lc->write_data);
 }
 
 struct strnsplit_int_data {
@@ -642,8 +648,12 @@ ssize_t lc_process(struct lolcat *lc, const char *buffer, size_t len)
 				lc->was_bgset = lc->was_reverse =
 					lc->was_bold = lc->was_underline =
 					false;
+				if (lc->bash_escape)
+					lc->write("\\[", 2, lc->write_data);
 				lc->write(buffer, sizeof(buffer),
 					  lc->write_data);
+				if (lc->bash_escape)
+					lc->write("\\[", 2, lc->write_data);
 			}
 			lc->x = 0;
 			lc->y++;
@@ -681,9 +691,16 @@ void lolcat_set_size(struct lolcat *lc, int w, int h)
 	lc->h = h;
 }
 
-static void usage()
+static void usage(const char *binname)
 {
-	fprintf(stderr, "Usage: nyancat [-t2] [file...]\n");
+	fprintf(stderr,
+		"Usage: %s [-t12vb] [file...]\n"
+		" -t    24-bit true color output (default)\n"
+		" -1    16 color output\n"
+		" -2    256 color output\n"
+		" -b    Escape color codes with \\[ \\] for bash prompt\n"
+		" -v    Make rainbowaves vertical\n",
+		binname);
 	exit(0);
 }
 
@@ -725,9 +742,12 @@ int main(int argc, char **argv)
 			case 'v':
 				lc->transpose = true;
 				break;
+			case 'b':
+				lc->bash_escape = true;
+				break;
 			case 'h':
 			default:
-				usage();
+				usage(argv[0]);
 				break;
 			}
 		}
@@ -792,7 +812,10 @@ int main(int argc, char **argv)
 		}
 	}
 
-	fprintf(stdout, "\x1b[0m");
+	if (lc->bash_escape)
+		fprintf(stdout, "\\[\x1b[0m\\]");
+	else
+		fprintf(stdout, "\x1b[0m");
 
 	return 0;
 }