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PHP 文件指针

2022-04-21

在PHP开发语言之中，共支持feof()、rewind()、ftell()、fseek()等函数进行文件指针操作

判断指针是否处于文件EOF

feof
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<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<title>demo</title>
</head>
<body>
	<?php
		$file = "D:/Program Files (x86)/phpStudy/WWW/text/1.txt";
		$hand = fopen($file, "r");

		// 重置指针位置
		rewind($hand);

		if (feof($hand)) {
			echo "当前指针处于文件尾部";
		} else {
			echo "当前指针不处于指针尾部，处于：",ftell($hand);
		}
	?>
</body>
</html>

当前指针位置

ftll()

feof()函数主要用于测试文件指针是否处于EOF；

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<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<title>demo</title>
</head>
<body>
	<?php
		$file = "D:/Program Files (x86)/phpStudy/WWW/text/1.txt";
		$hand = fopen($file, "r");
    	// 输出当前指针位置
		echo "当前指针为：",ftell($hand)."<br>";

	?>
</body>
</html>

挪动指针位置

fseek()
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<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<title>demo</title>
</head>
<body>
	<?php
		$file = "D:/Program Files (x86)/phpStudy/WWW/text/1.txt";
		$hand = fopen($file, "r");
    
		// 将指针挪动2
		fseek($hand, 2);
		echo "当前指针为：",ftell($hand)."<br>";

	?>
</body>
</html>

重置指针位置

rewind()
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<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<title>demo</title>
</head>
<body>
	<?php
		$file = "D:/Program Files (x86)/phpStudy/WWW/text/1.txt";
		$hand = fopen($file, "r");

		// 重置指针位置
		rewind($hand);
		echo "当前指针为：",ftell($hand)."<br>";
	?>
</body>
</html>
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