PHP file processing—writing files and operating files

PHP file processing - writing files and operating files

In PHP file processing, there are opening and closing files and reading files. Fetching also includes reading a line, characters, strings, and the entire file. So since there is reading, there must be writing. In today's article, we will give you a detailed explanation of writing files and operating files!

What we just talked about is in the first three articles "PHP File Processing—Open/Close File", "PHP File Processing—Read File (One Character, String) " and "PHP File Processing—How to Read Files (One Line, Entire File)" have detailed introductions. Friends who have not read it can check it out! Today we mainly explain writing files and file operations.

1: Write data to a file

Writing data is also a commonly used file operation in PHP. Use fweite() and The file_put_contents() function writes data to a file.

1. When can fwrite() be called? It is also called fputs(). Their usage is the same. The fwrite() function syntax is as follows:

int fwrite ( resource $handle , string $string [, int $length ] )

This function writes the content string into the file pointed to by the pointer handle. If the parameter length is specified, it will stop after writing length bytes. If the file content length is less than length, the entire file content will be output.

2. The file_put_contents() function is a new function in PHP5. The syntax format of this function is as follows:

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

• filename is the file to which data is to be written

• data is the data to be written

• flags can be FILE_USE_INCLUDE_PATH, FILE_APPEND or LOCK_EX, where LOCK_EX is an exclusive lock, which we will introduce in detail in the following article !

Using the file_put_contents() function achieves the same function as calling the fopen(), fwrite(), and fclose() functions in sequence. Let’s compare the superiority of functions through specific strengths!

This example first uses the fwrite() function to write data to the file, and then uses the file_put_contents() function to write data. The specific example code is as follows:

<?php
header("Content-Type:text/html; charset=utf-8");
$filepath = "05.txt";
$str = "PHP中文网  www.php.cn";
echo "用fwrite函数写入文件";
$fopen = fopen($filepath,"wb")or die("文件不存在");
fwrite($fopen,$str);
fclose($fopen);
readfile($filepath);
echo "<p>用file_put_contents函数写入文件：";
file_put_contents($filepath,$str);
readfile($filepath);
?>

The output result is:

2: Operating files

In addition to reading and writing the contents of the file, PHP can also perform operations on the file itself. Operations, such as: copy, rename, view modification date, etc. PHP has a large number of built-in file operation functions. The commonly used file operation functions are as follows:

##bool copy(string path1,string path2) Copy files from path1 to path2. Returns true if successful, false if failed. copy('tm.txt','../tm.txt')bool rename(string filename1,string filename2) Rename name1 to name2rename('1.txt','test.txt')bool unlink(string filename) Delete the file, return true if successful, false if failed. unlink('tm.txt')int fileatime(string filename)Returns the time when the file was last accessed, in Linux time Return by stamping fileatime('test.txt')int filemtime(string filename)Return the time when the file was last modified , returns date("Y-m-d int in the form of Linux timestamp filesize(string filename)Get the size of file filenamefilesize('1.txt')array pathinfo (string name[,int options])Returns an array containing the path information of the file name. There are dirname, basename and extension. The information to be returned can be set through option, including PATHINFO_DIRNAME, PATHINFO_BASENAME and PATHINFO_EXTENSION. The default is to return all$arr=pathinfo('/tm/s1/16/4/9/1.txt');string realpath(string filename)Return the absolute path of file filename, such as D:\wampserver\www\test\test.txtrealpath(test.txt)array stat(string filename)Returns an array, including file-related information, such as the file size, last modification time, etc. mentioned above. $arr=stat('test.txt');

Function prototype	Function description	Example
		H:i:s",filemtime("test.txt"))
	(bytes)
		foreach($arr as $method=>$ value){ echo $method.":".$value." ";}
		foreach($arr as $method=>$value){ echo $method.": ".$value." "; }

Note:

When reading and writing files, in addition to file(), Except for a few functions such as readfile(), you must first use the fopen() function to open the file, and finally use the fclose() function to close the file. File information functions (such as filesize, filemtime, etc.) do not need to be opened. File, as long as the file is saved!

PHP file processing ends here. In the following article, we will process the PHP directory. For details, please read "

PHP Directory Processing—Open/Close Directory"!

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