PHP learning file processing and file Upload courseware

Mainly includes PHP file processing, file processing, file pointer-related processing functions, file control functions PHP file processing
In the application of PHP files on the server, the related scope is not only the various connection and access operations between the user and the server database, but also the file processing functions built in PHP, to process General files.

Basename -- returns the file name part of the path.
Syntax format: $ path = "/home/httpd/html/index. php ";
$ File = basename ($ path); // $ file is set to "index. php"
$ File = basename ($ path, ". php"); // $ file is set to "index"

Pathinfo (): current path of the analysis File
Syntax format: $ path_parts = pathinfo ("/www/htdocs/index.html ");
Echo $ path_parts ["dirname"]. "\ n";/www/htdocs file path
Echo $ path_parts ["basename"]. "\ n"; index.html file and extension
Echo $ path_parts ["extension"]. "\ n"; html file format

File type and related information
Filesize (): calculates the file size (byte)
Syntax format: $bytes=filesize(“a.txt ");
Echo $ bytes round ($ bytes/1024,2 );
Fileatime (): Last file access time (timestamp)
Syntax format: echo date ("Y-m-d g: I: sa", fileatime );
Filectime (): File creation time
Syntax format: echo date ("Y-m-d g: I: sa", filectime );
Filemtime (): Last file update time
Syntax format: echo date ("Y-m-d g: I: sa", filemtime );
Fileperms (): File attributes and 10-digit permission
Syntax format: echo substr(base_convert(fileperms(a.txt), 10, 8), 3 );
Fileowner (): uid of the file owner (available only in Linux)
Syntax format: echo fileowner()a.txt ");

File operations
'R' is opened in read-only mode. it directs the file pointer to the file header.
Open in 'R + 'read/write mode and point the file pointer to the file header.
Open in 'W' writing mode, point the file pointer to the file header, and cut the file size to zero. If the file does not exist, try to create it.
Open in 'W + 'read/write mode, point the file pointer to the file header, and cut the file size to zero. If the file does not exist, try to create it.
Open the 'A' write mode and point the file pointer to the end of the file. If the file does not exist, try to create it.
Open in 'A + 'read/write mode and point the file pointer to the end of the file. If the file does not exist, try to create it.

'X' is created and opened in writing mode. it directs the file pointer to the file header. If the file already exists, fopen () fails to be called, returns FALSE, and generates an E_WARNING-level error message. If the file does not exist, try to create it. This is equivalent to specifying the O_EXCL | O_CREAT mark for the underlying open (2) system call. This option is supported by PHP 4.3.2 and later versions and can only be used for local files.
'X + 'is created and opened in read/write mode. the file pointer points to the file header. If the file already exists, fopen () fails to be called, returns FALSE, and generates an E_WARNING-level error message. If the file does not exist, try to create it. This is equivalent to specifying the O_EXCL | O_CREAT mark for the underlying open (2) system call. This option is supported by PHP 4.3.2 and later versions and can only be used for local files.

Fopen () -- open a file or URL
Fclose () -- close an opened file pointer
Fread () -- read file content
Fwrite () -- write a file
Syntax format: if (! $ F = @ fopen ("file03.php", "x") {// open a file and write data using the x method
Die ("file read failed"); // read failed
}
Fwrite ($ f, "kkkkkkkkk"); // what to write to that file
Echo fread ($ f, 10); // read the content of this file
Fclose ($ f); close opening a file


File () -- read the entire file into an array
Syntax format: $ arr = file ("file03.php ");
Print_r ($ arr); // read the array returned by the file

Readfile () -- read a file and write it to the output buffer.
Syntax format: $ str = readfile ("file03.php ");
Echo $ str; output

Writing a file recorder:
$ F = fopen ("file03.php", "r ");
$ I = fread ($ f, 1000 );
Echo "this is your {$ I} access ";
Fclose ($ f );
$ F = fopen ("file03.php", "w ");
$ I ++;
Fwrite ($ f, $ I );
Fclose ($ f );
"""""""""""""'
File_get_contents ()-read the entire file into a string
Syntax format: file_get_contents (file name or URL)

File_put_contents ()-? Writing a string to a file is the same as calling the fopen (), fwrite (), and fclose () functions in turn.
File_put_contents (file name, write data)


Feof () -- test whether the file pointer is at the end of the file
Ftell () -- returns the read/write position of the file pointer.
Syntax format: ftell (file pointer)
Flock ()-Lightweight consultation file locking
Syntax format: flock (file pointer, control parameter)
File pointer: it is a file pointer control parameter that has been opened (fopen:
"LOCK_SH" indicates that the shared Lock (read program) is to be obtained (set 1 in PHP4.0.1 or earlier versions ).
"LOCK_EX" indicates to obtain an exclusive lock (write program) (set to 2 in PHP4.0.1 or earlier versions ).
"LOCK_UN" indicates to release the lock (whether shared or exclusive) (set to 3 in PHP4.0.1 or earlier versions ).
"LOCK_NB" indicates that if you do not want flock () to be blocked during the lock, add this parameter to the control parameter.

Fseek () -- Locate in file pointer
Syntax structure: fseek (file pointer, moving number of characters [, starting position constant])
File pointer: it cannot be used to open the returned file pointer in the format of "http: //" or "ftp: //" in fopen.
Number of characters to be moved: when the number is positive, move the object pointer forward to the specified number: when the number is negative, move the object pointer backward to the specified number:
Start position constant:
SEEK_CUR-set the current position.
SEEK_SET-the position is equal to the beginning of the file. (Default)
SEEK_END-set the position to the end of the file.


Rewind () -- returns the position of the file pointer, that is, moving the file pointer to the beginning of the file.
Syntax structure: rewind (file pointer)
Note: If you open the file in the append ("a" or "a +") mode, any data written to the file will always be appended, regardless of the file pointer location.

Chgrp () -- change the group to which the file belongs
Syntax structure: chgrp (file name, group name)

Filegroup () -- The Group for obtaining files
Syntax structure: filegroup (file name)

Chmod () -- change the file mode
Syntax structure: chmod (file name, permission constant) 755 666

Chown () -- change the file owner
Syntax structure: chown (file name, user)

Fileowner () -- get the file owner
Syntax structure: fileowner (file name)
Posix_getpwuid () to resolve it to the user name.



Copy () -- copy an object
Syntax structure: copy (source file, target file)
Return type: bool type. if it is successful, TRUE is returned. if it fails, FALSE is returned.
Parameter description: Future source files will be copied to the target file.
Unlink () -- delete an object
Syntax structure: unlink (target file)
Return type: bool type. if it is successful, TRUE is returned. if it fails, FALSE is returned.
Parameter description: deletes a specified target file.
Rename () -- rename a file or directory
Syntax structure: rename (old file name, new file name)
Return type: bool type. if it is successful, TRUE is returned. if it fails, FALSE is returned.
Parameter description: try to rename the old file name as the new file name.

File attribute processing
File_exists () -- check whether a file or directory exists
Syntax structure: file_exists (file name)
Return type: bool type. If yes, true is returned. otherwise, false is returned.
Filesize () -- get the file size
Syntax structure: filesize (file name)
Return type: number of file size bytes. If an error occurs, false is returned.
Filetype () -- get the file type
Syntax structure: filetype (file name)
Return type: type of the returned file. Possible values include fifo, char, dir, block, link, file, and unknown. If an error occurs, false is returned.
Is_dir () -- determines whether the specified file name is a directory.
Syntax structure: is_dir (name)
Return type: If the file name exists and is a directory, true is returned; otherwise, false is returned.
Is_executable () -- determines whether a given file name can be executed
Syntax structure: is_executable (name)
Return type: if the object exists and can be executed, TRUE is returned; otherwise, FALSE is returned.
Is_file () -- determine whether the given file name is a normal file
Syntax structure: is_file (name)
Return type: if the object exists and is a normal object, TRUE is returned.
Is_link () -- determines whether a given file name is a symbolic connection
Syntax structure: is_link (name)
Return type: true is returned if the object exists and is a symbolic connection.
Is_readable () -- determines whether the specified file name is readable.
Syntax structure: is_readable (file name)
Return type: Returns TRUE if the object exists and is readable.
Is_writable () -- determines whether a given file name can be written.
Syntax structure: is_writable (file name)
Return type: If the file exists and can be written, TRUE is returned.


Directory reading through the iterator interface
Standard Iterator interface method
Current (): returns the element values in the current list.
Next (): used to move a position down in a list.
Valid (): checks whether there is another element in the current list. If yes, true is returned; otherwise, false is returned.
Rewind (): You can access the list of elements of a specified feature. when you start to operate iterator, the pointer is set to the top.