Data commit

Task/Terminal-control-Unicode-output/UNIX-Shell/terminal-control-unicode-output.sh

@@ -0,0 +1,24 @@
+unicode_tty() {
+  # LC_ALL supersedes LC_CTYPE, which supersedes LANG.
+  # Set $1 to environment value.
+  case y in
+  ${LC_ALL:+y})		set -- "$LC_ALL";;
+  ${LC_CTYPE:+y})	set -- "$LC_CTYPE";;
+  ${LANG:+y})		set -- "$LANG";;
+  y)			return 1;;  # Assume "C" locale not UTF-8.
+  esac
+  # We use 'case' to perform pattern matching against a string.
+  case "$1" in
+  *UTF-8*)		return 0;;
+  *)			return 1;;
+  esac
+}
+
+if unicode_tty; then
+  # printf might not know \u or \x, so use octal.
+  # U+25B3 => UTF-8 342 226 263
+  printf "\342\226\263\n"
+else
+  echo "HW65001 This program requires a Unicode compatible terminal" >&2
+  exit 252    # Incompatible hardware
+fi