# sapi_windows_vt100_support

(PHP 7 >= 7.2.0)

sapi_windows_vt100_support — Get or set VT100 support for the specified stream associated to an output buffer of a Windows console.

### 说明

sapi_windows_vt100_support ( resource `$stream` [, bool `$enable` ] ) : bool

If `enable` is omitted, the function returns `TRUE` if the stream `stream` has VT100 control codes enabled, `FALSE` otherwise.

If `enable` is specified, the function will try to enable or disable the VT100 features of the stream `stream`. If the feature has been successfully enabled (or disabled), the function will return `TRUE`, or `FALSE` otherwise.

At startup, PHP tries to enable the VT100 feature of the `STDOUT`/`STDERR` streams. By the way, if those streams are redirected to a file, the VT100 features may not be enabled.

If VT100 support is enabled, it is possible to use control sequences as they are known from the VT100 terminal. They allow the modification of the terminal's output. On Windows these sequences are called Console Virtual Terminal Sequences.

Warning

This function uses the `ENABLE_VIRTUAL_TERMINAL_PROCESSING` flag implemented in the Windows 10 API, so the VT100 feature may not be available on older Windows versions.

### 参数

`stream`

  The stream on which the function will operate.

`enable`

  If specified, the VT100 feature will be enabled (if `TRUE`) or disabled (if `FALSE`).

### 返回值

If `enable` is not specified: returns `TRUE` if the VT100 feature is enabled, `FALSE` otherwise.

If `enable` is specified: 成功时返回 `TRUE`， 或者在失败时返回 `FALSE`。

### 范例

Example #1 sapi_windows_vt100_support() default state

By default, `STDOUT` and `STDERR` have the VT100 feature enabled.

    php -r "var_export(sapi_windows_vt100_support(STDOUT));echo ' ';var_export(sapi_windows_vt100_support(STDERR));"

以上例程的输出类似于：

    true true

By the way, if a stream is redirected, the VT100 feature will not be enabled:

    php -r "var_export(sapi_windows_vt100_support(STDOUT));echo ' ';var_export(sapi_windows_vt100_support(STDERR));" 2>NUL

以上例程的输出类似于：

true false

Example #2 sapi_windows_vt100_support() changing state

You won't be able to enable the VT100 feature of `STDOUT` or `STDERR` if the stream is redirected.

    php -r "var_export(sapi_windows_vt100_support(STDOUT, true));echo ' ';var_export(sapi_windows_vt100_support(STDERR, true));" 2>NUL

以上例程的输出类似于：

    true false

Example #3 Example usage of VT100 support enabled

    <?php
    $out = fopen('php://stdout','w');
    fwrite($out, 'Just forgot a lettr.');
    // Moves the cursor two characters backwards
    fwrite($out, "\033[2D");
    // Inserts one blank, shifting existing text to the right -> Just forgot a lett r.
    fwrite($out, "\033[1@");
    fwrite($out, 'e');
    ?>

以上例程会输出：

    Just forgot a letter.