Whether connected to a terminal that supports ANSI escape sequences.
Not all terminals are recognized, and not all recognized terminals can report whether they support ANSI escape sequences, so this value is a best-effort attempt at detecting the support.
The actual escape sequence support may differ between terminals, with some terminals supporting more escape sequences than others, and some terminals even differing in behavior for the same escape sequence.
The ANSI color selection is generally supported.
Currently, a TERM environment variable containing the string xterm
will be taken as evidence that ANSI escape sequences are supported.
On Windows, only versions of Windows 10 after v.1511
("TH2", OS build 10586) will be detected as supporting the output of
ANSI escape sequences, and only versions after v.1607 ("Anniversery
Update", OS build 14393) will be detected as supporting the input of
ANSI escape sequences.
Source
bool get supportsAnsiEscapes => _supportsAnsiEscapes(_fd);