//定義expect腳本
$expect_script = "spawn ping 127.0.0.1\n";
$expect_script .= "expect {\n";
$expect_script .= " \"(timeout)\" {\n";
$expect_script .= " exit 1\n";
$expect_script .= " }\n";
$expect_script .= " eof {}\n";
$expect_script .= "}\n";
$expect_script .= "exit 0\n";
//調用expect腳本
$output = "";
exec("expect -c '$expect_script'", $output);
//輸出ping的結果
foreach ($output as $line) {
echo "" . $line . "
";
}這個示例中，首先定義了一個expect腳本，用于調用ping命令并獲取輸出結果。然后使用exec函數調用expect并傳遞腳本內容作為參數。最后將獲取的輸出結果逐行輸出。
除了執行ping操作外，expect還可以用于執行一些需要交互操作的命令行工具，比如SSH、Telnet等。使用expect可以模擬用戶輸入密碼、執行命令并獲取輸出結果。如下面這個例子，使用expect和SSH協議連接到遠程服務器并執行命令：//定義expect腳本
$expect_script = "spawn ssh user@server\n";
$expect_script .= "expect {\n";
$expect_script .= " \"password:\" {\n";
$expect_script .= " send \"my_password\n\"\n";
$expect_script .= " exp_continue\n";
$expect_script .= " }\n";
$expect_script .= " \">\" {\n";
$expect_script .= " send \"ls -la /home/user\n\"\n";
$expect_script .= " expect \">\"\n";
$expect_script .= " }\n";
$expect_script .= " eof {}\n";
$expect_script .= "}\n";
$expect_script .= "exit 0\n";
//調用expect腳本
$output = "";
exec("expect -c '$expect_script'", $output);
//輸出命令執行結果
foreach ($output as $line) {
echo "" . $line . "
";
}這個示例中，首先定義了一個expect腳本，用于連接到遠程服務器并執行命令。然后使用exec函數調用expect并傳遞腳本內容作為參數。最后將獲取的輸出結果逐行輸出。
總之，expect是一個非常強大的庫，可以使PHP獲得更廣泛的應用場景。當需要執行一些交互式命令時，使用expect可以很方便地模擬用戶的操作，獲取命令執行結果。