PHP文件操作详解
本文是对PHP文件操作的详解教程，很详细，很全面，现在分享给大家，希望对学习PHP开发的朋友有所帮助。
代码如下:
$path1= "E:/myphp/text.txt";
if(!file_exists($path1)){
echo "文件不存在！";
}else{
$handle1 = fopen($path1, 'r+') or exit("Unable to open file");
// while (!feof($handle1)){
// echo fgets($handle1)."
";
// }
while(!feof($handle1)){
echo fgetc($handle1);
}
}
上面的代码阐释了一个简单的文件读取操作。说明下：
fopen是打开文件资源。
使用方法：
$file=fopen("welcome.txt","r");
具体意思：第一个参数是文件的路径。后面的参数是要求用何种方式打开文件，有下面几种类型：
r 只读。在文件的开头开始。
r+ 读/写。在文件的开头开始。
w 只写。打开并清空文件的内容；如果文件不存在，则创建新文件。
w+ 读/写。打开并清空文件的内容；如果文件不存在，则创建新文件。
a 追加。打开并向文件文件的末端进行写操作，如果文件不存在，则创建新文件。
a+ 读/追加。通过向文件末端写内容，来保持文件内容。
x 只写。创建新文件。如果文件已存在，则返回 FALSE。
x+
读/写。创建新文件。如果文件已存在，则返回 FALSE 和一个错误。
注释：如果 fopen() 无法打开指定文件，则返回 0 (false)。
比较常用的是前面的4个。
fgetc:
string fgetc ( resource$handle )
返回一个包含有一个字符的字符串，该字符从 handle 指向的文件中得到。碰到 EOF 则返回FALSE。
fgets:
string fgets ( int$handle [,int$length ] )
从 handle 指向的文件中读取一行并返回长度最多为length - 1 字节的字符串。碰到换行符（包括在返回值中）、EOF 或者已经读取了 length - 1 字节后停止（看先碰到那一种情况）。如果没有指定length，则默认为 1K，或者说 1024 字节。
出错时返回 FALSE。
fgetss:
string fgetss ( resource$handle [,int$length [,string$allowable_tags ]] )
和 fgets() 相同，只除了 fgetss 尝试从读取的文本中去掉任何 HTML 和 PHP 标记。(跟fgets()相同，只是他过滤了html和php的标记而已。)
可以用可选的第三个参数指定哪些标记不被去掉。
feof() 函数检测是否已到达文件末尾 (eof)。
//判断文件或目录是否存在
bool file_exists(string filename)
判断文件或目录是否存在，存在则返回真，否则返回假
格式：
代码如下:
if(file_exists(“hello.txt”))
{
Echo “文件存在”；
}
//打开文件
格式：
fopen(filename,mode)
说明：按指定的格式打开指定的文件
filename:要打开的文件名
mode : 打开模式
fopen(“hello.txt”,”w”);
表示以写的方式打开hello.txt文件
//写文件
格式：
fwrite(resource,string);
说明：在打开的文件中添加指定的内容
resource:打开的文件
string：要写入的内容
例：
$handle = fopen(“hello.txt”,”w”) //若a ,则可追加数据
fwrite($handle,”1\r\n”)
//关闭文件
格式：
fclose($handle)
说明：关闭打开的文件
例：
$handle = fopen(“hello.txt”,”w”);
fclose($handle);
//读取一行数据
格式：
fgets(int handle[,int length])
说明：读取length-1个字符。若没有指定length,则默认字节为1KB,
若遇到换行、EOF或则已经读取了length-1个字符，则程序终止，
出错时候返回false;
例：
$handle = fopen(“hello.txt”,”r”);
$buffer = fgets($handle,1024);
echo $handle; //输出一行信息
//读取整个文件
格式：
readfile(filename)
说明：读取整个文件，并输出到浏览器
例：
readfile(“hello.txt”);
?>
//取文件大小
格式：
filesize(filename)
说明：获取指定文件大小，出错返回false
例：
filesize(“a.rar”)
//删除文件
格式：
unlink()
说明：删除一个文件，成功则返回true,否则返回false
例：
unlink(“b.txt”)
//创建目录
格式：
mkdir(dirname)
说明：创建一个目录
例：mkdir(“newfolder”); //当前目录下创建新文件夹
//删除目录
格式：
rmdir(dirname)
说明：删除一个目录
例：rmdir(“newfolder”);
//取得文件名
格式：
basename(filepath)
说明：从指定的路径中返回文件名
例：
basename(“c:\mytools\a.txt”) //返回a.txt
//获取文件路径信息
pathinfo(path)
说明：返回文件路径信息，结果保存在数组中，数组下标为
dirname(路径) , basename（文件名） , extension（扩展名）
例：pathinfo(“c:\mytools\a.txt”)
//取绝对路径
格式：
realpath(filename)
说明：取指定文件的绝对路径，失败则返回false
例：realpath(“h.txt”) //F:\apache\www.jnwebseo.com\h.txt
//复制文件
格式：
copy(source,dest)
说明：将source文件复制到dest处
例：copy(“h.txt”,”newfloder\a.txt”)
//判断是否是目录
格式：
is_dir(filename)
说明：判断给定文件名是否是一个目录。如果filename存在并且
为目录，则返回true,否则返回false.
例：
代码如下:
if(is_dir(“newfolder”))
{
echo “是文件目录”；
}
//打开目录
格式：opendir(path)
说明：打开一个指定文件目录，返回一个资源标示符
例：
$hand = opendir(“.”) //打开根目录
//读取目录
格式：
readdir($handle)
说明：读取一个打开的文件目录流
readdir($hand);
//关闭目录
格式：
closedir($handle)
说明：关闭一个打开的目录流
例：closedir($hand);
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