字符操作

字符串输出: 字符串输出格式与C语言保持一致,

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<?php
	// printf 普通的输出函数
	$string = "hello lyshark";
	$number = 1024;
	printf("%s page number = > %u <br>",$string,$number);
	
	// sprintf 将内容输出到缓冲区中
	$text = sprintf("float = > %0.2f",$number);
	echo "打印输出内容: " . $text . "<br>";
	
	// 打开文件,如果打开失败则提示die中的内容
	$url = "./index.php";
	fopen($url,"r") or die("Unable to connect $url");
 
// substr("123123",2,2);
?>

字符串处理函数:

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<?php
	$string = "@@ hello lyshark  @@";
 
	// 字符串左右去除
	printf("字符串长度: %d <br>",strlen($string));
	printf("字符串截取: %s <br>",substr($string,2,4));
	printf("去除左侧空字符: %s <br>",ltrim($string));
	printf("去除左侧@字符: %s <br>",ltrim($string,'@'));
	printf("去除右侧@字符: %s <br>",rtrim($string,'@'));
	printf("去除两边@字符: %s <br>",trim($string,'@'));
	
	// 字符串自动补齐
	echo "右边补齐: " . str_pad($string,50,"-") . "<br>";
	echo "左边补齐: " . str_pad($string,50,"-",STR_PAD_LEFT) . "<br>";
	echo "两边补齐: " . str_pad($string,50,"-",STR_PAD_BOTH) . "<br>";
	
	// 字符串大小写转换
	echo "全部小写: " . strtolower($string) . "<br>";
	echo "全部大写: " . strtoupper($string) . "<br>";
	echo "首字母大写: " . ucwords($string) . "<br>";
	
	// 反转字符串与MD5
	echo "反转字符串: " . strrev($string) . "<br>";
	echo "MD5 加密: " . md5($string) . "<br>";
?>

字符串比较(字节序): 字节序比较可以使用strcmp/strcasecmp两个函数,只需传入两个字符串即可.

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<?php
	$username="lyshark"; $password="Abc123^";
	
	// 不区分大小写比较字符串
	if(strcasecmp(strtolower($username),"lyshark") == 0)
		printf("用户名正确.. <br>");
	
	// 区分大小写验证密码
	switch(strcmp($password,"Abc123^"))
	{
		case 0:
			echo "两个字符串相等.";break;
		case 1:
			echo "第一个大于第二个.";break;
		case -1:
			echo "第一个小于第二个.";break;
	}
	
	// 字符串实现冒泡排序
	$info= array("file11.txt","file22.txt","file1.txt","file2.exe");
	function MySort($array)
	{
		for($x=0; $x<count($array); $x++)
			for($y=0;$y<count($array)-1; $y++)
				if(strnatcmp($array[$y],$array[$y+1]))
				{
					$tmp = $array[$y];
					$array[$y] = $array[$y+1];
					$array[$y+1] = $tmp;
				}
		return $array;
	}
	print_r(MySort($info));
?>

字符串替换/切割: 将字符串切割为多个部分,替换字符串,与连接字符串等操作.

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<?php
	// 实现截取文件后缀
	function getFileName($url)
	{
		$location = strrpos($url,"/")+1;    // 获取URL中最后一个/出现的位置
		$fileName = substr($url,$location); // 截取从location位置到结尾的字符
		return $fileName;
	}
	echo getFileName("http://www.baidu.com/index.php") . "<br>";
	echo getFileName("file://c://windows/php.ini") . "<br>";
	
	// 实现字符串替换
	$string = "BASH Linux PHP MySQL Ruby Metasploit linux";
	echo "将Linux替换为Win: " . str_replace("Linux","Windows",$string,$count) . "<br>";
	echo "将Linux替换为Win: " . str_ireplace("Linux","Windows",$string,$count) . "<br>";
	
	$search = array("http","www","jsp","com");        // 搜索字符串
	$replace = array("https","bbs","php","net");      // 替换字符串
	$url = "http://www.baidu.com/index.jsp";
	echo "数组替换: " . str_replace($search,$replace,$url) . "<br>";
	
	// 实现字符串切割与链接
	$info = "Linux Apache MySQL PHP Web";
	$str_cat = explode(" ",$info);
	echo "切割后: " . $str_cat[1] . $str_cat[2] . "<br>";
	
	$info = "root:*:0:0::/home/dhat:/bin/bash";
	list($user,$pass,$uid,$gid,,$home,$shell) = explode(":",$info);
	echo "切割后: 用户-> " . $user . " 终端Bash -> " . $shell . "<br>";
	
	$info = array("linux","Apache","MySQL","PHP");
	echo "链接字符串: " . implode("+",$info) . "<br>";
	echo "链接字符串: " . join("+",$info) . "<br>";
?>

正则匹配字符串: 通过使用正则我们同样可以对字符串进行匹配,切片,组合,查找等操作.

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<?php
	/*
	邮箱： '/^\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*$/'
	正整数： '/^\d+$/'
	qq号码：'/^\d{5,11}$/'
	手机号码： '/^1(3|4|5|7|8)\d{9}$/'
	*/
	// 简单的正则匹配方法
	$pattern = "/\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*/";
	$subject = 'aaa 1181506874@qq.com test admin@blib.cn ddd';
	$recv = preg_match_all($pattern, $subject,$match,PREG_SET_ORDER);
	echo "匹配记录: " . $recv . "条, 值: " . $match[0][0] . "," . $match[1][0] . "<br>";
	
	// 匹配数组中符合条件的字符串
	$array = array("LinuxHat","Nginx 2.2.3","Apache 2.29","PHP");
	$pattern_version = preg_grep("/^[a-zA-Z ]+(\d|\.)+$/",$array);
	print_r($pattern_version); echo "<br>";
	
	// 正则实现字符串替换
	$pattern = "/[!@#$]/";
	$text = "你@好!,当前日#期 01/25/2020 总#共365天";
	echo "替换特殊符号为空: " . preg_replace($pattern,"",$text) . "<br>";
	$pattern = "/(\d{2})\/(\d{2})\/(\d{4})/";
	echo "替换实现时间翻转: " . preg_replace($pattern,"\${3}-\${1}-\${2}",$text) . "<br>";
	
	// 正则实现字符串切割
	$keyworks = preg_split("/[\s,]/","php,nginx, mysql python");
	echo "切割字符串为数组: "; print_r($keyworks); echo "<br>";
	
	$keyworks = preg_split("//","lyshark",-1,PREG_SPLIT_NO_EMPTY);
	echo "将字符串切割为字符: "; print_r($keyworks); echo "<br>";
?>

文件操作

读文件基本信息: 文件基本信息包括文件类型,文件的创建日期等基本信息.

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<?php
	$Path = "C://Windows/System32/drivers/etc/hosts";
	
	echo "文件类型: " . filetype($Path) . "<br>";
	echo "文件建立时间: " . date("Y年m月j日",filectime($Path))."<br>";
	echo "文件最后更改时间: " . date("Y年m月j日",filemtime($Path))."<br>";
	echo "文件最后打开时间: " . date("Y年m月j日",fileatime($Path))."<br>";
	
	if(file_exists($Path))
		printf("文件存在 <br>");
	
	if(is_file($Path))
		printf("是一个文件 <br>");
	
	if(is_dir($Path))
		printf("是一个目录 <br>");
	
	if(is_readable($Path))
		printf("文件可读 <br>");
	
	if(is_writable($Path))
		printf("文件可写 <br>");
	
	if(is_executable($Path))
		printf("文件可执行 <br>");
?>

判断文件类型: 虽然我们可以通过filetype()函数判断文件类型,但是不够具体,如下是具体的判断流程.

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<?php
	$Path = "C://Windows/System32/drivers/etc/hosts";
	
	function GetFileType($FileName)
	{
		switch(filetype($FileName))
		{
			case "file": $type = "普通文件"; break;
			case "dir": $type = "目录文件"; break;
			case "block": $type = "块设备文件"; break;
			case "fifo": $type = "命名管道文件"; break;
			case "link": $type = "符号文件"; break;
			case "unknown": $type = "未知文件"; break;
			default: $type = "没有检测到"; break;
		}
		return $type;
	}
	
	$type = GetFileType($Path);
	printf("文件类型: %s <br>",$type);
?>

获取文件大小:

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<?php
	$Path = "C://Windows/System32/drivers/etc/hosts";
	
	function GetFileSize($bytes)
	{
		if($bytes >= pow(2,40))
		{
			$return = round($bytes/pow(1024,4),2);
			$suffix = "TB";
		}else if($bytes >= pow(2,30))
		{
			$return = round($bytes/pow(1024,3),2);
			$suffix = "GB";
		}else if($bytes >= pow(2,20))
		{
			$return = round($bytes/pow(1024,2),2);
			$suffix = "MB";
		}else if($bytes >= pow(2,10))
		{
			$return = round($bytes/pow(1024,1),2);
			$suffix = "KB";
		}else
		{
			$return = $bytes;
			$suffix = "Byte";
		}
		return $return . " " . $suffix;
	}
	
	$ret = GetFileSize(filesize($Path));
	echo "文件实际大小: " . $ret . "<br>";
?>

文件与目录解析:

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<?php
	// 返回文件基本信息数组
	$Path = "C://Windows/System32/drivers/etc/hosts";
	
	$FilePro = stat($Path);
	echo "文件基本信息: "; print_r(array_slice($FilePro,13)); echo "<br>";
	
	// 返回路径中的 page.php 文件名
	$Path = "/var/www/html/page.php";
	echo "带文件扩展名输出: " . basename($Path) . "<br>";
	echo "不带文件扩展名输出: " . basename($Path,".php") . "<br>";
	
	// 返回路径的所在位置
	echo "文件所在位置: " . dirname($Path) . "<br>";
	
	// 返回目录中文件详细信息
	$path_parts = pathinfo($Path);
	echo "路径: " . $path_parts["dirname"] . "<br>";
	echo "文件: " . $path_parts["basename"] . "<br>";
	echo "扩展名: " . $path_parts["extension"] . "<br>";
?>

文件读写操作: 读写文件首先需要使用fopen函数打开文件,然后使用fread读取,fwrite写入,最后使用fclose释放句柄.

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<?php
	// 从文件中读出前100个字节
	$handle = fopen("c://test.log","r") or die("Open File Err");
	$context = fread($handle,100);
	echo $context;
	fclose($handle);
	
	// 循环从文件中读取全部数据
	$handle = fopen("c://test.log","r") or die("Open File Err");
	$context = "";
	
	while(!feof($handle))
	{
		$context = fread($handle,1024);
	}
	fclose($handle);
	echo $context;
	
	// 另一种读取全文的方式
	$handle = fopen("c://test.log","r") or die("Open File Err");
	$context = fread($handle,filesize("c://test.log"));
	fclose($handle);
	echo $context;
	
	// 每次读入一个字符,直到读取结束
	$handle = fopen("c://test.log","r") or die("Open File Err");
	while(false !==($char = fgetc($handle)))
	{
		echo $char . "<br>";
	}
 
	// 读取远程文件,并输出
	$file = fopen("http://www.baidu.com","r");
	while(!feof($file))
	{
		$line = fgets($file,1024);
		echo $line;
	}
	fclose($file);
	
	// 文件写入数据
	$handle = fopen("c://new.txt","w") or die("open file error");
	for($row=0; $row<10; $row++)
	{
		fwrite($handle,$row . "www.baidu.com \n");
	}
	fclose($handle);
?>

遍历文件目录: 遍历目录中文件,主要用到opendir打开为文件,readdir每次读入一条记录,最后closedir关闭句柄.

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<?php
	$Path = "d://";
	$dir_handle = opendir($Path);
	
	echo "<table border='1' width='600' cellspacing='0' cellpadding='0' align='center'>";
	echo "<caption><h2>目录: " . $Path . "</h1></caption>";
	echo "<tr align='left' bgcolor='#ddddddd'>";
	echo "<th>文件名</th><th>文件大小</th><th>文件类型</th><th>修改时间</th></tr>";
	
	while($each = readdir($dir_handle))
	{
		$dir_file_path = $Path . "/" . $each;    // 将目录与文件连接起来
		if($num++ % 2 == 0)                      // 控制奇数行与偶数行不同的颜色输出
			$bgcolor='#ffccf';
		else
			$bgcolor='#ccfff';
		
		echo "<tr bgcolor=" . $bgcolor . ">";
		echo "<td>" . $dir_file_path . "</td>";
		echo "<td>" . filesize($dir_file_path) . "</td>";
		echo "<td>" . filetype($dir_file_path) . "</td>";
		echo "<td>" . date("Y/n/t",filemtime($dir_file_path)) . "</td>";
		echo "</tr>";
	}
	echo "</table>";
	closedir($dir_handle);
	echo "目录: " . $Path . "总共有: " . $num . " 个文件" . "<br>";
?>

统计目录总容量: 计算文件磁盘目录的总大小,具体思路是递归遍历将每次遍历到的文件大小存入变量递增.

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<?php
	echo "磁盘剩余大小: " . disk_free_space("c://") . "<br>";
	echo "磁盘总计大小: " . disk_total_space("c://") . "<br>";
	
	function GetDirSize($directory)
	{
		$dir_size = 0;
		
		// 首先打开目录,并判断目录是否打开成功
		if($dir_handle = @opendir($directory))
		{
			// 循环每次读入一个目录下的所有文件
			while($filename = readdir($dir_handle))
			{
				// 判断目录文件,排除. .. 两个无效路径
				if($filename != "." && $filename != "..")
				{
					$file_path = $directory . "/" . $filename;
					// 如果是目录,则需要继续递归调用自身函数
					if(is_dir($file_path))
						$dir_size += GetDirSize($file_path);
					// 如果是文件则统计大小
					if(is_file($file_path))
						$dir_size += filesize($file_path);
				}
			}
		}
		closedir($dir_handle);
		return $dir_size;
	}
	
	$dir_size = GetDirSize("D://htmlcss/");
	echo "目录大小: " . round($dir_size/pow(1024,2),2). "MB" . "<br>";
	echo "目录大小: " . round($dir_size/pow(1024,1),2). "KB" . "<br>";
?>

目录递归拷贝: 如果需要拷贝单个文件可以直接使用copy函数,如果要拷贝目录则需要递归拷贝.

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<?php
	function CopyFileDir($dir_src,$dir_dst)
	{
		if(is_file($dir_dst))
		{
			printf("目标不是目录,无法执行.");
			return;
		}
		if(!file_exists($dir_dst))
			mkdir($dir_dst);
		
		// 首先打开目录,并判断目录是否打开成功
		if($dir_handle = @opendir($dir_src))
		{
			// 循环每次读入一个目录下的所有文件
			while($filename = readdir($dir_handle))
			{
				// 判断目录文件,排除. .. 两个无效路径
				if($filename != "." && $filename != "..")
				{
					$sub_file_src = $dir_src . "/" . $filename;
					$sub_file_dst = $dir_dst . "/" . $filename;
					
					if(is_dir($sub_file_src))
						CopyFileDir($sub_file_src,$sub_file_dst);
					if(is_file($sub_file_src))
						copy($sub_file_src,$sub_file_dst);
				}
			}
			closedir($dir_handle);
		}
		return $dir_size;
	}
 
	// 将d://test目录,拷贝到c://test
	CopyFileDir("d://test","c://test");
?>

目录递归删除: 递归删除需要先调用unlink函数将目录中每个文件都删掉,然后赞调用rmdir删除空目录.

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<?php
	function DelFileDir($directory)
	{
		// 判断目录是否存在
		if(file_exists($directory))
		{
			if($dir_handle = @opendir($directory))
			{
				while($filename = readdir($dir_handle))
				{
					if($filename!='.' && $filename != "..")
					{
						$sub_file = $directory . "/" . $filename;
						if(is_dir($sub_file))
							DelFileDir($sub_file);
						if(is_file($sub_file))
							unlink($sub_file);
					}
				}
				closedir($dir_handle);
				rmdir($directory);
			}
		}
	}
	
	// 删除c://test整个目录
	DelFileDir("c://test");
?>