PHP function operation file creation

PHP is a widely used server-side scripting language that is widely used to develop web applications. When developing web applications, we need to frequently perform file operations, such as creating, reading, and editing files. This article will introduce the use of file creation functions in PHP.

There are two commonly used functions for creating files in PHP, namely fopen() and file_put_contents().

1. fopen() function

fopen() function is to open the file. If the file exists, it will return the pointer (file handle) of the file after opening the file. If the file If it does not exist, an attempt will be made to create the file and then the pointer will be returned. The syntax is as follows:

resource fopen ( string $filename , string $mode [, bool $use_include_path = FALSE [, resource $context ]] )

Parameter description:

• $filename: file path and file name, which can contain absolute path or relative path. If the file does not exist, an attempt is made to create the file.
• $mode: File opening mode, including read (r), write (w), append (a) and other modes. The specific modes are as follows:

Mode	Description
r	Read-only mode, the pointer will be at the beginning of the file after opening the file
r	Read-write mode, the pointer will be at the beginning of the file after opening the file
w	Write-only mode, the file content will be cleared when opening the file, and the file will be created if it does not exist
w	Read-write mode, the file content will be cleared when opening the file, if the file does not exist, the file will be created
a	Append mode, write at the end of the file Data, if the file does not exist, create the file
a	Append mode, read-write mode, write data at the end of the file, if the file does not exist, create the file

• $use_include_path: Whether to use include_path (the include_path setting directory will be searched) for search, the default is false, that is, not used.
• $context: Context parameter of the file handle.

The following is an example of using the fopen() function to create a file:

<?php
$myfile = fopen("testfile.txt", "w") or die("Unable to open file!"); //打开testfile.txt文件，如果文件不存在则创建文件
$txt = "Hello World!
"; //要写入文件的内容
fwrite($myfile, $txt); //将内容写入文件
fclose($myfile); //关闭文件
?>

As shown in the above code, when using the fopen() function to create a file, you need to specify the file name and opening mode. Here we specify the opening mode as w (write-only mode), which means that after opening the file, the file contents will be cleared, and the file will be created if it does not exist. Next, we use the fwrite() function to write data to the file and use the fclose() function to close the file.

2. file_put_contents() function

The function of file_put_contents() is to directly write data to a file without opening a file handle. If the file does not exist, an attempt is made to create the file. The syntax is as follows:

int file_put_contents ( string $filename , mixed $data [, int $flags = 0 [, resource $context ]] )

Parameter description:

• $filename: file path and file name, which can contain absolute path or relative path. If the file does not exist, an attempt is made to create the file.
• $data: The data to be written to the file, which can be a string, array or other types of data.
• $flags: Flags for writing files. The specific flags are as follows:

## FlagDescription##FILE_USE_INCLUDE_PATHFILE_APPENDLOCK_EX

If include_path is included in the file path, use it
Append data to the end of the file
Try to acquire an exclusive lock to prevent the file from being modified by other processes

$context: Context parameter of the file handle.

The following is an example of using the file_put_contents() function to create a file:

<?php
$txt = "Hello World!
"; //要写入文件的内容
file_put_contents("testfile.txt", $txt); //将内容写入文件
?>

As shown in the above code, when using the file_put_contents() function to create a file, you need to specify the file name and write data, creating the file if it does not exist. This method can write data directly without opening a file handle. Of course, if you want to operate on the file, such as appending data, you can use the flags parameter.

Conclusion

In PHP, file operations are very common operations, and creating files is one of the basic operations. This article introduces two commonly used ways to create files, namely the fopen() and file_put_contents() functions. If you need to perform other file operations, it is recommended to learn more about the use of PHP file operation functions.

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