PHP 中的 file_put_contents

file_put_contents 是一個 PHP 函數，用於將指定的資料字串寫入檔案。如果相關文件不存在，則會建立該文件。相反，如果文件存在，則其內容將被指定的資料覆蓋。此功能實現簡單，只需將檔案名稱和資料寫入參數作為參數即可。此外，還可以透過指定 URL 或使用標誌修改函數的行為來將資料寫入遠端檔案。 file_put_contents 是一個有價值的工具，可用於多種用途，例如儲存表單資料、產生日誌檔案或透過建立書面記錄進行偵錯。

廣告 該類別中的熱門課程 精通內容行銷：成功策略 - 專業化 | 4門課程系列

開始您的免費軟體開發課程

網頁開發、程式語言、軟體測試及其他

語法與參數

file_put_contents 函數的語法和參數對其正確使用和行為至關重要。語法定義了函數的結構和所需的參數順序。參數本身允許指定目標檔案、要寫入的資料以及修改函數行為的選項。清楚地理解 file_put_contents 函數的語法和參數對於準確有效地使用該函數非常重要。

文法：

file_put_contents(filename, data, [flags, context]);

參數：

參數	描述
$檔名（必填）	「$filename」是 file_put_contents 函數中的參數，用來指定要寫入資料的檔案的名稱和位置。 $filename 參數是必需的，指定資料將寫入的目標檔案。
$資料（必填）	$data 是一個變量，它保存將使用 PHP 中的 file_put_contents() 函數寫入檔案的內容。它可以是字串、陣列或任何其他 PHP 資料類型。資料在寫入檔案之前將被轉換為字串。 「$data」參數中傳遞的資料將寫入「$filename」中指定的檔案。
$flags（選購）	$flags 是 PHP 中 file_put_contents() 的可選參數，用於設定特定標誌來控製檔案寫入操作的執行方式。它可用來修改 file_put_contents() 函數在寫入檔案方面的行為。 $flags 參數採用一個或多個預定義常數作為控制寫入模式的值。一些常用的常數包括： FILE_USE_INCLUDE_PATH – 此標誌可讓您在 include_path 中搜尋檔案。如果在目前目錄中沒有找到該文件，則搜尋包含的路徑。 FILE_APPEND – 此標誌以附加模式開啟文件，並將資料寫入文件結尾。如果文件不存在，則會建立該文件。 LOCK_EX – 此標誌導致檔案被鎖定以進行獨佔寫入存取。這意味著在解鎖之前沒有其他進程可以寫入該檔案。 FILE_TEXT – 此標誌將檔案模式設為文字。這用於文字文件，行結束符會轉換為系統的預設值。 FILE_BINARY – 此標誌將檔案模式設為二進位。這用於二進位文件，行結尾不會轉換。 The default value of the $flags parameter in the file_put_contents function is 0.
$context (optional)	The context parameter in the file_put_contents function in PHP allows the user to specify a set of options that modify the behavior of the function when it writes data to a file or a remote server. The context is specified as an associative array that defines options for a stream, such as headers to be sent along with a request, timeout values, encryption method, etc. It allows the user to control the way data is sent and received through a stream in PHP.
$mode (optional)	The $mode parameter is an optional parameter and is not typically used in the file_put_contents function. $mode is a parameter in the file_put_contents function in PHP that specifies the access mode when opening the file. The value of $mode determines what kind of access the function has to the file, such as read-only or write-only access. By default, file_put_contents opens the file with write-only access. This means that the function can only write data to the file and cannot read the existing data in the file.

Examples

Here an array of data is converted to a JSON string and written to a remote URL using an HTTP POST request. The stream_context_create function is used to create a stream context resource that specifies the HTTP method, header information, and timeout for the request. The file_put_contents function is then used to send the JSON data to the specified URL using the specified context. The function then returns the number of bytes written to the file, or false if there is any error. The response is checked to determine if the data was sent successfully, and a message is displayed accordingly.

Example #1

Code:

<?php
$data = array("name" => "John Doe", "email" => "[email protected]", "phone" => "555-555-1212");
$json = json_encode($data);
$context = stream_context_create(array(
'http' => array(
'method' => 'POST',
'header' => "Content-Type: application/json\r\n".
"Accept: application/json\r\n".
"User-Agent: My PHP Script",
'content' => $json,
'timeout' => 60
)
));
$response = file_put_contents("https://www.example.com/api/create_user", $json, 0, $context);
if ($response === false) {
echo "Error: Could not send data to remote server.";
} else {
echo "Data successfully sent to remote server. Response: $response";
}
?>

Output:

The output in the above example would be a message indicating the success or failure of the data being sent to the remote server. If the data is sent successfully, the output would be:

If an error occurs, the output would be:

Example #2

Code:

<?php
$file = "https://cdn.educba.com/var/www/html/students.txt";
$data = "1, Alice, 23, History, 3.7\n2, Bob, 25, Mathematics, 3.9\n3, Charlie, 22, English, 3.5\n4, Dave, 24, Computer Science, 4.0\n";
// Writing data to the file
file_put_contents($file, $data);
// Check if the file was written successfully
if (file_exists($file)) {
echo "Data was successfully written to the file.";
} else {
echo "An error occurred while writing data to the file.";
}
?>

Output:

The output for the code would depend on the server’s response to the request. If the request was successful, the output would be:

If the request was unsuccessful, the output would be:

Conclusion

file_put_contents is a useful PHP function for writing data to a file. It has several parameters that allow you to control the behavior of the function, such as the file path, data to be written, and the mode in which the file is opened. With the help of the optional stream context, file_put_contents can even write data to remote servers. This function is a simple and efficient way to write data to a file, making it a popular choice among PHP developers.

Recommended Article

In this article, you learned about file_put_contents in PHP. To know more about the topic, you can refer to these articles.

1. PHP 7 MySQL
2. PHP 7 mysql_connect 
3. PHP Timestamp
4. PHP urlencode

以上是PHP 中的 file_put_contents的詳細內容。更多資訊請關注PHP中文網其他相關文章！