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PHP is a powerful programming language. It can not only handle various network requests as a Web programming language, but also handle various file operations through a series of file streams and file management technologies. This article will focus on the file stream and file management technology in PHP, and discuss their use and common techniques in practical applications.
First, let’s talk about file streams in PHP. File streaming refers to the process of treating files as a series of data streams and implementing operations such as reading, writing, copying, and deleting files through a series of stream operations. In PHP, we can implement these operations through some basic file stream functions, such as fopen, fclose, fread, fwrite, etc. The following are some common file stream processing techniques:
$file=fopen("test.txt","r"); echo fread($file,filesize("test.txt")); fclose($file);
This code first opens a file named "test.txt" and then uses the fread function to read the entire file Content. Finally, we close the file handle using the fclose function.
$file=fopen("test.txt","w"); fwrite($file,"Hello World"); fclose($file);
This code first opens a file named "test.txt" and then uses the fwrite function to write a string written to the file. Finally, we close the file handle using the fclose function.
copy("test.txt","test_backup.txt");
This code copies a file named "test.txt" and saves a copy of it as "test_backup. txt".
We can also use the unlink function to delete a file, as shown below:
unlink("test.txt");
This code will delete the file named "test.txt". Please note that once a file is deleted, it cannot be recovered.
In addition to file stream processing techniques, PHP also provides some file management techniques, such as file upload, directory traversal, etc. Here are some common file management tips:
HTML form:
<form action="upload.php" method="post" enctype="multipart/form-data"> <input type="file" name="fileToUpload" id="fileToUpload"><br /> <input type="submit" value="Upload File" name="submit"> </form>
Upload script:
$target_dir = "uploads/"; $target_file = $target_dir . basename($_FILES["fileToUpload"]["name"]); if (move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $target_file)) { echo "The file ". basename( $_FILES["fileToUpload"]["name"]). " has been uploaded."; } else { echo "Sorry, there was an error uploading your file."; }
This code Saves the uploaded files in a folder called "uploads" and returns a message when the upload is complete.
$dir = "/path/to/dir"; $files = scandir($dir); foreach($files as $file) { echo $file . "<br />"; }
This code lists the names of all files and subdirectories in a specified directory.
In short, file stream processing and file management are very important technologies in PHP. The techniques and functions introduced above are just the tip of the iceberg. There are many other useful functions and techniques in PHP that allow us to better handle files and directories. I hope readers can use them flexibly in actual development to create better web applications.
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