Example test of feof() function in PHP, phpfeof_PHP tutorial
Example test of feof() function in PHP, phpfeof
The example in this article describes the usage of the feof() function in PHP. It has conducted certain tests on the feof() function, which is of great practical value. The specific analysis is as follows:
The example running environment of this article:
OS: Mac OS X 10.8.4
PHP: 5.3.15
In the official PHP manual, there is a lot of discussion about the function feof(). Some related tests have been done as follows.
The test code is as follows:
<?php
print <<<EOF
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>测试PHP中的feof()函数效果</title>
</head>
<body>
<div>
EOF;
function bool2str($bool) {
if ($bool == TRUE) {
return "TRUE";
} else {
return "FALSE";
}
}
/*
* 请随便创建一个文件。
* 比如：本测试中，在脚本文件的相同路径下创建了一个文本文件，
* 文件内容为“abcdefg”，文件名为“7bytesfile”。
*/
$filename = './7bytesfile';
$handle = fopen($filename, 'r');
if (!$handle) {
die("文件打开失败");
}
for($i = 0; $i <= filesize($filename); $i++) {
fseek($handle, $i);
echo "文件位置" . ftell($handle) . "：<br />\n";
echo "执行fseek，尚未执行读取操作之前，feof结果：" . bool2str(feof($handle)) . "<br />\n";
echo "当前位置字符：" . fgetc($handle) . "<br />\n";
echo "执行文件读取操作之后，feof结果：" . bool2str(feof($handle)) . "<hr />\n";
}
/*
* 通过上面一段代码可以观察到，
* 随着循环的执行，文件指针从文件头一直移动到文件末尾。
* 但是当完成了字符“g”的读取输出，文件指针继续向后移动，这是feof()依然返回False。
* 只有当执行了一次fgetc()操作之后，才返回true，表示到达文件末尾。
*/
echo "ftell()结果：". ftell($handle). "<hr />\n";
//输出一下，很郁闷的发现文件指针的位置还是7。+_+
fseek($handle, 4);
echo "文件位置" . ftell($handle) . "：<br />\n";
echo "执行fseek，尚未执行读取操作之前，feof结果：" . bool2str(feof($handle)) . "<br />\n";
echo "当前位置字符：" . fgetc($handle) . "<br />\n";
echo "执行文件读取操作之后，feof结果：" . bool2str(feof($handle)) . "<hr />\n";
fseek($handle, 7);
echo "文件位置" . ftell($handle) . "：<br />\n";
echo "执行fseek，尚未执行读取操作之前，feof结果：" . bool2str(feof($handle)) . "<br />\n";
echo "当前位置字符：" . fgetc($handle) . "<br />\n";
echo "执行文件读取操作之后，feof结果：" . bool2str(feof($handle)) . "<hr />\n";
fclose($handle);
//再次移动文件指针，效果依旧。
//再用另外一段代码测试一下：
$handle = fopen($filename, 'r');
if (!$handle) {
die("文件打开失败");
}
while (!feof($handle)) {
$char = fgetc($handle);
if ($char === FALSE) {
echo 'FALSE';
} else {
echo $char;
}
}
fclose($handle);
//依然是输出了字符g之后，再次执行读取操作，才终止循环。
print <<<EOF
</div>
</body>
</html>
EOF;
?>
The guess for this situation is that in PHP, the implementation of feof() does not directly check the position of the file pointer relative to the file, but returns the result based on a certain identifier. This flag will be set to "False" after each fseek(). Only after a file content reading operation is performed, the flag will be set based on the result of the file reading.
Based on this guess, two code logics can be used.
One method is to directly detect the execution results of content reading functions (such as fgetc(), fgets()) without performing feof() detection.
The sample code is as follows:
while (($content = fgets($fileHandle)) !==FALSE) {
//文件内容处理……
}
This method of processing takes advantage of PHP’s criticized function return method, so it must use “===” or “!==” for detection. The code cannot be simplified to:
while ($content = fgets($fileHandle)) {}
Another method is to read the file first and then enter the feof() loop , as shown below:
$content = fgets($fileHandle);
while (!feof($fileHandle)) {
//处理文件内容……
$content = fgets($fileHandle);
}
After testing, the former method is more efficient.
I hope the examples in this article will be helpful to everyone in PHP programming.
The feof(fp) function detects whether the end of file (eof) has been reached.
There are two return values: if the end of file is encountered, the value of function feof(fp) is non-zero, otherwise it is 0.
Let me tell you about feof() first. This function is to determine whether the file has ended. !feof() means that the file has not ended yet. If you use the if statement, the result you get is that if the file is not ended, execute the following statement and get 12342, which is normal, because this condition is only executed once according to your requirements. If you want to get your result, you must make it loop and judge. Add a loop statement to it! while(!feof($file)){}
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1662
14
1419
52
1313
25
1262
29
1235
24
How do you parse and process HTML/XML in PHP?
Feb 07, 2025 am 11:57 AM
This tutorial demonstrates how to efficiently process XML documents using PHP. XML (eXtensible Markup Language) is a versatile text-based markup language designed for both human readability and machine parsing. It's commonly used for data storage an
Explain JSON Web Tokens (JWT) and their use case in PHP APIs.
Apr 05, 2025 am 12:04 AM
JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,
Explain late static binding in PHP (static::).
Apr 03, 2025 am 12:04 AM
Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.
PHP Program to Count Vowels in a String
Feb 07, 2025 pm 12:12 PM
A string is a sequence of characters, including letters, numbers, and symbols. This tutorial will learn how to calculate the number of vowels in a given string in PHP using different methods. The vowels in English are a, e, i, o, u, and they can be uppercase or lowercase. What is a vowel? Vowels are alphabetic characters that represent a specific pronunciation. There are five vowels in English, including uppercase and lowercase: a, e, i, o, u Example 1 Input: String = "Tutorialspoint" Output: 6 explain The vowels in the string "Tutorialspoint" are u, o, i, a, o, i. There are 6 yuan in total
What are PHP magic methods (__construct, __destruct, __call, __get, __set, etc.) and provide use cases?
Apr 03, 2025 am 12:03 AM
What are the magic methods of PHP? PHP's magic methods include: 1.\_\_construct, used to initialize objects; 2.\_\_destruct, used to clean up resources; 3.\_\_call, handle non-existent method calls; 4.\_\_get, implement dynamic attribute access; 5.\_\_set, implement dynamic attribute settings. These methods are automatically called in certain situations, improving code flexibility and efficiency.
PHP and Python: Comparing Two Popular Programming Languages
Apr 14, 2025 am 12:13 AM
PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.
PHP in Action: Real-World Examples and Applications
Apr 14, 2025 am 12:19 AM
PHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.
PHP: A Key Language for Web Development
Apr 13, 2025 am 12:08 AM
PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7
