PHP 中的 file_put_contents

file_put_contents 是一个 PHP 函数，用于将指定的数据字符串写入文件。如果相关文件不存在，则会创建该文件。相反，如果文件存在，则其内容将被指定的数据覆盖。该功能实现简单，只需将文件名和数据作为参数写入即可。此外，还可以通过指定 URL 或使用标志修改函数的行为来将数据写入远程文件。 file_put_contents 是一个有价值的工具，可用于多种用途，例如存储表单数据、生成日志文件或通过创建书面记录进行调试。

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语法和参数

file_put_contents 函数的语法和参数对其正确使用和行为至关重要。语法定义了函数的结构和所需的参数顺序。参数本身允许指定目标文件、要写入的数据以及修改函数行为的选项。清楚地理解 file_put_contents 函数的语法和参数对于准确有效地使用该函数非常重要。

语法：

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

参数：

参数	描述
$文件名（必填）	“$filename”是 file_put_contents 函数中的一个参数，用于指定要写入数据的文件的名称和位置。 $filename 参数是必需的，指定数据将写入的目标文件。
$数据（必填）	$data 是一个变量，它保存将使用 PHP 中的 file_put_contents() 函数写入文件的内容。它可以是字符串、数组或任何其他 PHP 数据类型。数据在写入文件之前将被转换为字符串。 “$data”参数中传递的数据将写入“$filename”中指定的文件。
$flags（可选）	$flags 是 PHP 中 file_put_contents() 的可选参数，用于设置特定标志来控制文件写入操作的执行方式。它可用于修改 file_put_contents() 函数在写入文件方面的行为。 $flags 参数采用一个或多个预定义常量作为控制写入模式的值。一些常用的常量包括： FILE_USE_INCLUDE_PATH – 此标志允许您在 include_path 中搜索文件。如果在当前目录中没有找到该文件，则搜索包含的路径。 FILE_APPEND – 此标志以附加模式打开文件，并将数据写入文件末尾。如果文件不存在，则会创建该文件。 LOCK_EX – 此标志导致文件被锁定以进行独占写入访问。这意味着在解锁之前没有其他进程可以写入该文件。 FILE_TEXT – 此标志将文件模式设置为文本。这用于文本文件，行结束符会转换为系统的默认值。 FILE_BINARY – 此标志将文件模式设置为二进制。这用于二进制文件，行结尾不会转换。 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

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