(Advanced article) PHP folder and file directory operation function Introduction

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PHP folder operation function

String basename (String path [, string suffix])

Give a string containing a full path to a file, this function returns the base file name. If the file name ends in suffix, then this part will be removed as well.
In Windows, slashes (/) and backslashes () can be used as directory separators. In other environments it is a slash (/).

String dirname (String path)

Gives a string containing a full path to a file, which returns the directory name after removing the file name.
In Windows, slashes (/) and backslashes () can be used as directory separators. In other environments it is a slash (/).

Array pathinfo (string path [, int options])

PathInfo () returns a federated array containing information about path. Includes the following array cells: dirname,basename and extension.
You can specify which cells to return through the parameters options. They include: Pathinfo_dirname,pathinfo_basename and Pathinfo_extension. The default is to return all cells.

String Realpath (String path)

Realpath () expands all the symbolic connections and processes the '/./' in the input path, '/'. /' and extra '/' and returns the normalized absolute path name. The path returned does not have a symbolic connection, '/./' or '/'. /' ingredient.
Realpath () returns FALSE when it fails, for example if the file does not exist. On BSD systems, if only path does not exist, PHP does not return FALSE as other systems do.

BOOL Is_dir (string filename)

Returns TRUE if the file name exists and is a directory. If filename is a relative path, the relative path is checked according to the current working directory.
Note: The result of this function is cached. See Clearstatcache () for more information.

Resource Opendir (string path [, resource context])

Opens a directory handle that can be used later in the Closedir (), Readdir (), and Rewinddir () calls.

String Readdir (Resource Dir_handle)

Returns the file name of the next file in the directory. The file name is returned as a sort in the file system.

void Closedir (Resource dir_handle)

Closes the directory stream specified by Dir_handle. The stream must be opened previously by Opendir ().

void Rewinddir (Resource dir_handle)

Resets the directory stream specified by Dir_handle to the beginning of the directory.

Array Glob (string pattern [, int flags])

The Glob () function looks for all file paths that match the pattern in accordance with the rules used by the libc glob () function, similar to the rules used for general shells. No abbreviation extensions or parameter overrides are performed.
Returns an array that contains a matching file/directory. Returns FALSE if an error occurs.

Valid tokens are:
Glob_mark-Add a slash to each returned item
Glob_nosort-Returns (not sorted) according to the original order in which the files appear in the directory
Glob_nocheck-Returns the mode used for search if no file matches
Glob_noescape-Backslash does not escape meta-characters
Glob_brace-expand {a,b,c} to match ' A ', ' B ' or ' C '
Glob_onlydir-Returns only catalog entries that match the pattern

Note: prior to PHP 4.3.3, Glob_onlydir is not available on Windows or other systems that do not use the GNU C library.
Glob_err-Stop and read error messages (such as unreadable directories), ignoring all errors by default
Note: Glob_err is added to PHP 5.1.

PHP File directory Operations

New file
1. First determine what to write to the file

$content = ' Hello ';

2. Open this file (the system will automatically create this empty piece)

Suppose the newly created file is called File.txt and is in the parent directory. W means ' Write file ', $fp below to indicate an open file. $fp = fopen ('.. /file.txt ', ' W ');

3. Writing a content string to a file

$fp tells the system to write to the file, writes the content is $contentfwrite ($fp, $content);

4. Close the file

Fclose ($FP);

Description: The PHP5 provides a more convenient function file_put_contents, the above 4 steps can be done:

$content = ' Hello '; file_put_contents (' file.txt ', $content);

deleting files

Delete the file Abc.txtunlink (' Arch/abc.txt ') under the Arch directory under the current directory;

Note: The system returns the result of the operation, the success returns TRUE, the failure returns FALSE, the variable can be received, you know whether to delete the success:

$deleteResult = unlink (' Arch/abc.txt ');

Get file Contents

Assume that the target file name obtained is file.txt and is in the parent directory. Gets the contents into the $content. $content = file_get_contents ('.. /file.txt ');

Modify File Contents
The operation method is basically the same as the new content

Renaming a file or directory

Rename the file 1.gif below subdirectory A in the current directory to 2.gif. Rename ('/a/1.gif ', '/a/2.gif ');

Description: The same is true for directories. The system returns the result of the operation, the success returns TRUE, the failure returns FALSE, and the variable can be received, knowing whether the rename succeeds.

$renameResult = Rename ('/a/1.gif ', '/a/2.gif ');

If you want to move a file or directory, simply set the renamed path to the new path:

Move the file 1.gif below subdirectory A in the current directory to subdirectory b under the current directory, and rename to 2.gif. Rename ('/a/1.gif ', '/b/2.gif ');

Note, however, that if directory B does not exist, it will fail to move.

Copying files

Copy the file 1.gif under subdirectory A in the current directory to subdirectory b under the current directory, and name it 2.gif. Copy ('/a/1.gif ', '/b/1.gif ');

Description: This operation cannot be performed on the directory.
If the target file (above/b/1.gif) already exists, the original file will be overwritten.
The system returns the result of the operation, the success returns TRUE, the failure returns FALSE, and the variable can be received to know if the copy was successful.

$copyResult = Copy ('/a/1.gif ', '/b/1.gif ');

Move a file or directory
Action methods and renaming are the same

Whether the file or directory exists

Check if the file logo.jpg is present in the parent directory. $existResult = File_exists ('.. /logo.jpg ');

Description: Returns False if the file exists system returns TRUE. You can do the same for the directory.

Get File size

Gets the size of the file logo.png under the parent directory. $size = FileSize ('.. /logo.png ');

Description: The system returns a number that indicates how many bytes (bytes) The size of the file is.

New Catalog

Under directory A in the current directory, create a new directory B. mkdir ('/a/b ');

Note: The system returns the result of the operation, the success returns TRUE, the failure returns FALSE, and can be received with the variable, knowing whether to create a new success:

$mkResult = mkdir ('/a/b ');

Delete Directory

Delete subdirectory B under directory A in the current directory. RmDir ('/a/b ');

Note: You can only delete directories that are not empty, or you must first delete subdirectories and files under the directory, and then delete the total directory
The system returns the result of the operation, the success returns TRUE, the failure returns FALSE, and the variable can be received to know if the deletion succeeded:

$deleteResult = rmdir ('/a/b ');

Get all the file names in the directory
1. Open the directory you want to manipulate, and point to it with a variable

Open the directory under the current directory under Pic subdirectory common. $handler = Opendir (' Pic/common ');

2. Read all the files in the directory under the loop

/* Where $filename = Readdir ($handler) is the file name to be read each time the loop is assigned to $filename, in order not to be trapped in the dead loop, so also let $filename!== false. Be sure to use!==, because if a file name is called ' 0 ', or if some are considered false by the system, you will stop looping */while (($filename = Readdir ($handler))!== false)  {      3, There will be two files in the catalogue with the name '. ' and '. ', do not operate on them      if ($filename! = "." && $filename! = "...") {      4, for processing      //Here simply use echo to output the file name      echo $filename;}      }

5. Close the Directory

Closedir ($handler);

Whether the object is a directory

Check whether the target object logo.jpg under the parent directory is a directory. $checkResult = Is_dir ('.. /logo.jpg ');

Description: Returns False if the target object is a directory system that returns TRUE. The $checkresult of the above example is of course false.

Whether the object is a file

Check whether the target object logo.jpg under the parent directory is a file. $checkResult = Is_file ('.. /logo.jpg ');

Description: If the target object is a file, the system returns TRUE, otherwise false is returned. The $checkresult of the above example is of course true.

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