PHP file Directory operation implementation Program (_php) tutorial

In PHP, there are specific functions for file or directory operations, such as Fopen,rdir,filesize,opendir,readdir,fcolse,fread, which are file and directory manipulation functions.

Second, directory operation

The first introduction is a function read from the directory, Opendir (), Readdir (), Closedir (), using the file handle is opened first, and then the iteration is listed:

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$base _dir = "filelist/"; $fso = Opendir ($base _dir); echo $base _dir. " " ; while ($flist =readdir ($FSO)) { echo $flist. " " ; } Closedir ($FSO) ?>

This is the return file directory under which the file is already in the directory program (0 file will return false).

Sometimes you need to know the directory information, you can use DirName ($path) and basename ($path), respectively, return the directory portion of the path and the file name part, the Disk_free_space ($path) to return to see space free space.

To create a command:

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mkdir ($path, 0777)

, 0777 is the permission code, and the Umask () function can be set under non-window.

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RmDir ($path)

The path to the $path file will be deleted.

DIR--The Directory class is also an important class to manipulate the file directory, there are 3 methods, Read,rewind,close, this is a copy object-oriented class, it first uses the open file handle, and then read by the way of the pointer. Here's a look at the PHP manual:

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$d = Dir ("/etc/php5"); echo "Handle:". $d->handle. "N"; echo "Path:". $d->path. "N"; while (false!== ($entry = $d->read ())) { echo $entry. " n "; } $d->close (); ?>

Output:

Handle:resource ID #2
Path:/ETC/PHP5
.
..
Apache
Cgi
Cli

The properties of the file are also very important, including the creation time, the last modified time, the owner, the file group, the type, the size, and so on.

Here we focus on file operations.

Third, file operation

Read the file

The first is a file to see if it can read (permission problems), or there is no, we can use the Is_readable function to obtain information.:

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$file = ' dirlist.php '; if (is_readable ($file) = = False) { Die (' file does not exist or cannot be read '); } else { echo ' presence '; } ?>

The function of judging the existence of a file is also file_exists (shown below), but this is obviously not is_readable comprehensive. When a file exists, it can be used

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$file = "filelist.php"; if (file_exists ($file) = = False) { Die (' file does not exist '); } $data = file_get_contents ($file); echo htmlentities ($data); ?>

However, the file_get_contents function is not supported on earlier versions, you can create a handle to the file first, and then read all with the pointer:

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$fso = fopen ($cacheFile, ' R '); $data = Fread ($fso, FileSize ($cacheFile)); Fclose ($FSO);

There is also a way to read a binary file:

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$data = Implode (', File ($file));

Write a file

and read the file the same way, first see if it can write:

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$file = ' dirlist.php '; if (is_writable ($file) = = False) { Die ("I'm chicken feathers, I can't"); } ?>

If you can write it, you can use the File_put_contents function to write:

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$file = ' dirlist.php '; if (is_writable ($file) = = False) { Die (' I'm chicken feathers, I can't '); } $data = ' I am contemptible, I want to '; File_put_contents ($file, $data); ?>

file_put_contents function in the php5 of the newly introduced function (do not know the existence of the function_exists function first to judge) the lower version of PHP is not available, you can use the following way:

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$f = fopen ($file, ' w '); Fwrite ($f, $data); Fclose ($f);

Replace it.

When writing a file, you sometimes need to lock and then write:

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function Cache_page ($pageurl, $pagedata) { if (! $fso =fopen ($pageurl, ' W ')) { $this->warns (' cannot open cache file. '); /trigger_error return false; } if (!flock ($fso, lock_ex)) {//LOCK_NB, exclusive type lock $this->warns (' cannot lock cache file. '); /trigger_error return false; } if (!fwrite ($fso, $pagedata)) {//write byte stream, serialize write to other format $this->warns (' cannot write to cache file. '); /trigger_error return false; } Flock ($fso, lock_un);//Release lock Fclose ($FSO); return true; }

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http://www.bkjia.com/PHPjc/629155.html www.bkjia.com true http://www.bkjia.com/PHPjc/629155.html techarticle in PHP, there are specific functions for file or directory operations, such as Fopen,rdir,filesize,opendir,readdir,fcolse,fread, which are file and directory manipulation functions. Second, the directory operation first introduced is ...

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