Reading, writing and operating methods of file data types in PHP

Reading, writing and operating methods of file data types in PHP

In PHP, files are a common data type that are often used to store and process various data. This article will introduce the reading, writing and operating methods of file data types in PHP, and illustrate it through code examples.

1. Opening and closing files

In PHP, you can use the fopen() function to open a file, the syntax is as follows:

$handle = fopen("file.txt", "r");

Above The code attempts to open a file named "file.txt" and assigns it to the $handle variable. The second parameter "r" means to open the file in read-only mode. Other open modes include "w" (write mode), "a" (append mode), etc.

After completing the operation on the file, you should use the fclose() function to close the file to release system resources:

fclose($handle);

2. Reading and writing of files

1. File reading

Use the fread() function to read data from the file:

$content = fread($handle, filesize("file.txt"));

The above code The contents of the entire file will be read and assigned to the $content variable. filesize()The function is used to get the size of the file.

In addition, you can also use the fgets() function to read the contents of the file line by line:

while(!feof($handle)) {
    $line = fgets($handle);
    echo $line;
}

The above code will read the contents of the file line by line and add each One line is output to the screen.

2. File writing

Use the fwrite() function to write data to the file:

$content = "Hello, world!";
fwrite($handle, $content);

The above code will The string "Hello, world!" is written to the file.

3. File operation method

1. File renaming

Use the rename() function to rename the file :

rename("file.txt", "newfile.txt");

The above code renames the file "file.txt" to "newfile.txt".

2. File copy

Use the copy() function to copy a file from one location to another:

copy("file.txt", "copy.txt");

Above The code copies the file "file.txt" to "copy.txt".

3. File deletion

Use the unlink() function to delete the file:

unlink("file.txt");

The above code will delete the file "file .txt".

4. File check

Use the file_exists() function to check whether the file exists:

if(file_exists("file.txt")) {
    echo "文件存在！";
} else {
    echo "文件不存在！";
}

The above code will check the file Whether "file.txt" exists, and output the corresponding prompt information.

To sum up, this article introduces the reading, writing and operating methods of file data types in PHP, and explains it through code examples. By mastering these methods, you can process and manage file data more efficiently.

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