PHP Mobile Internet Development Notes (5)--Upload and download files

First, the file upload

1. Client settings:

(1), in

Second, the file download

Simple file download only needs to use the HTML link tag, and specify the URL value of the attribute href to the downloaded file. This method only handles MIME type files that are not recognized by browsers.

In order to improve security and do not want the file link in the A tag, you must send the necessary header information to the browser, we can use the following code.

Third, the File function library

Touch

Set access and adornment time for files

BOOL Touch (string $filename [, int $time [, int $time]]

Copy

Copying files

BOOL Copy (string $source, String $dest)

Note: To move a file, use the Rename function

File_put_contents

Writes a string to a file

int file_put_contents (string $filename, String $data [, int $flag [, Resource $content]])

File_get_contents

Read the entire file to a string

String file_get_contents (String $filename [, bool User_include_path [, Resource $content [, int $offset [, int $maxlen]]])

Iv. Serialization and deserialization

Serialize

Serialization of

String serialize (mixed $value)

Note: Serialize (Kunming National Defense Road Hospital) can handle any type except Resouce. You can even serialize () those arrays that contain pointers to their own references.

Unserialize

Deserialization

Mixed Unserialize (String $str)

Date

Format a local time/date

String Date (string format[, int timestamp]);

GetDate

Get Date/Time information

Array getdate ([int timestamp]);

Microtime

Returns the current UNIX timestamp and number of microseconds

Mixed Microtime ([bool get_as_float]);

Date_default_timezone_set

Set the default time zone

BOOL Date_default_timezone_set (string timezone_identifier);

Date_default_timezone_get

Get the default time zone

String date_default_timezone_get (void);

Three, character function library

Strlen

Get string length

int strlen (string $str);

Strtolower

String converted to lowercase

String Strtolower (string $str);

Strtoupper

Convert string to uppercase

String Strtoupper (string $str);

Ucfirst

Capitalize first letter

String Ucfirst (string $str);

Ucwords

Convert the first letter of each word to uppercase

String Ucwords (string $str);

LTrim

Remove spaces or other characters from the beginning of a string

String LTrim (String $str [, String $charlist]);

RTrim

Remove spaces or other characters from the end of a string

String RTrim (String $str [, String $chirlist]);

Trim

Remove spaces or other characters from the beginning and end of a string

Str_replace

Character substitution

Mixed Str_ireplace (mixed $search, mixed $replace, mixed $subject, [int $count]);

Str_ireplace

Character substitution

Mixed Str_ireplace (mixed $search, mixed $replace, mixed $subject, [int $count]);

MD5

Computes the MD5 hash of a string

String MD5 (string $str [, bool $raw _output=false]);

Strpos

Returns the position of the first occurrence of a character in another character

int Strpos (String haystack, mixed needle[, int offset]);