Introduction to the use of SplFileObject class for reading large files in PHP_PHP Tutorial

If the loaded file is particularly large, such as hundreds of MB, and when it reaches GB, the performance will drop. So is there any function or class for processing large files in PHP? The answer is: yes.
PHP is really becoming more and more "object-oriented", and some of the original basic SPL methods have begun to implement classes one after another.
Starting from PHP 5.1.0, the SPL library has added two standard file operation classes: SplFileObject and SplFileInfo. SplFileInfo is implemented starting with PHP 5.1.2.
From the literal meaning, it can be seen that SplFileObject is more powerful than SplFileInfo.
Yes, SplFileInfo is only used to obtain some attribute information of the file, such as file size, file access time, file modification time, suffix name and other values, and SplFileObject inherits these functions of SplFileInfo.

Copy code The code is as follows:

/**Returns the content of the file from line Number of rows
* @return string
*/
function getFileLines($filename, $startLine = 1 , $endLine=50, $method='rb') {
$content = array();
$count = $endLine - $startLine;
// Determine the php version (because SplFileObject is used , PHP>=5.1.0)
if(version_compare(PHP_VERSION, '5.1.0', '>=')){
$fp = new SplFileObject($filename, $method);
$fp->seek($startLine-1);//Go to line N, the seek method parameters start counting from 0
for($i = 0; $i <= $count; ++$i ) {
                                                                                                                                                                                                                              ; > }else{//PHP<5.1
        $fp = fopen($filename, $method); =1;$i<$startLine;++$i) {// Skip the previous $startLine line
                                                                                                                                                ;++$i){
                                                                                               ($content); // array_filter filter: false,null,''
}

Ps: There is no "read to the end judgment" added above: !$fp->eof() Or !feof($fp), plus this judgment affects efficiency, you can know by yourself by testing the running time of many, many, many lines, and it is completely unnecessary to add it here.
It can be seen from the above function that using SplFileObject is much faster than fgets below, especially when the number of file lines is very large and the following content needs to be fetched. fgets requires two loops, and it needs to loop $endLine times.
This method took a lot of effort and tested many Chinese writing methods, just to find the most efficient method. If anyone thinks there is anything worth improving, please let me know.
Use, return the content of lines 35270-35280:



Copy code

The code is as follows:

echo '<pre>' ;
var_dump(getFileLines('test.php',35270,35280));

echo '</pre>';

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If the loaded file is particularly large, such as hundreds of MB, and when it goes up to GB, the performance will drop. , so is there any function or class for processing large files in PHP? The answer is: yes. PHP really...