agetty: add support for \e in issue file to print \033

Suggested-by: Victor Ananjevsky <ananasik@gmail.com>
Signed-off-by: Karel Zak <kzak@redhat.com>

term-utils/agetty.8

@@ -333,6 +333,9 @@ Insert the baudrate of the current line.
 d
 Insert the current date.
 .TP
+e
+Insert \\033 to handle esc sequences, for example "\\e[31m RED \\e[0m" prints red text.
+.TP
 s
 Insert the system name, the name of the operating system. Same as `uname \-s'.
 See also \\S escape code.

term-utils/agetty.c

@@ -2339,6 +2339,9 @@ static void output_special_char(unsigned char c, struct options *op,
 	uname(&uts);
 
 	switch (c) {
+	case 'e':
+		fputs("\033", stdout);
+		break;
 	case 's':
 		printf("%s", uts.sysname);
 		break;