PHP Developer''''s Dictionary- P33 pptx

PHP Developer’s Dictionary IT-SC book 160 Syntax string chop(string str) Description The chop() function returns the str parameter without any trailing whitespace. Whitespace includes "\\ n" , "\\ r" , "\\ t" , "\\ v" , "\\ 0" , and a plain space. chr() Syntax string chr(int ascii) Description The chr() function returns a one-character string that corresponds to the ASCII code specified by the parameter. echo chr(65);//displays A chunk_split() Syntax string chunk_split(string string, int [chunklen] , string [end]) Description The chunk_split() function, which was added in PHP 3.0.6 and PHP 4.0, returns string broken up at every chunklen characters by the string end . The optional parameter chunklen defaults to 76 , and end defaults to ( "\\ r\\ n" ). In other words, the default behavior is to take a long string and break it into multiple lines of length 76. This can be useful for converting base64-endcoded output to match RFC 2045 semantics. Base64 encoding is used to preserve binary data when transferring it via electronic mail. convert_cyr_string() PHP Developer’s Dictionary IT-SC book 161 Syntax string convert_cyr_string(string str, string from, string to); Description The convert_cyr_string() function, which was added in PHP 3.0.6 and PHP 4.0, returns str converted from one Cyrillic character set to another. The from and to parameters are single characters that represent Cyrillic character sets. The str is the character set to which it should be converted. The supported types of Cyrillic character sets are k—koi8-r w —Windows-1251 i —ISO8859-5 a —x-cp866 d —x-cp866 m —x-mac-cyrillic count_chars() Syntax mixed count_chars(string string, [mode]); Description The count_chars() function, which was added in PHP 4.0, counts the number of occurrences of each byte value (0–255) in string and returns the information in a format determined by mode . If mode is not specified, it defaults to 0 . The options for mode include: 0 —An array with the key representing the byte value and the value representing the frequency of each byte. 1 —An array similar to 0 but only non-zero frequency byte values are listed. 2 —An array similar to 0 but only zero frequency byte values are listed. PHP Developer’s Dictionary IT-SC book 162 3 —A string is returned containing only the byte values that are used. 4—A string is returned containing only the byte values that are not used. crc32() Syntax int crc32(string str) Description The crc32() function, which was added in PHP 4.0.1, calculates the crc32 polynomial of the string . This is typically used to validate data that has been transmitted. crypt() Syntax string crypt(string str, string [salt] ) Description The crypt() function encrypts str using the standard UNIX DES encryption method. The salt is an optional two-character parameter on which the encryption is based. If salt is not provided, PHP will randomly generate one. For some operating systems, an MD5-based encryption algorithm replaces the standard DES encryption. The encryption type is specified by the salt parameter. During installation of PHP, it is determined which encryption functions are in use on the system. If salt is not specified, PHP will auto-generate a salt based on the default encryption type for the system. Either the standard 2-character DES salt or a random MD5-compatible salt is generated. You can determine which encryption method is in use by examining the constant CRYPT_SALT_LENGTH . The output will contain the salt as the first two numbers when using the standard DES encryption crypt() function. On systems where multiple encryption types are supported, the crypt() function accepts either 0 or 1 , depending on whether the given type is available: CRYPT_STD_DES— Standard DES encryption with a 2-character salt CRYPT_EXT_DES— Extended DES encryption with a 9-char salt PHP Developer’s Dictionary IT-SC book 163 CRYPT_MD5— MD5 encryption with a 12-char salt where the first characters of the result are $1$ CRYPT_BLOWFISH—Extended DES encryption with a 16-char salt where the first characters of the result are $2$ Note that crypt() is a one-direction algorithm. The original str cannot be determined from the resulting string. echo() Syntax echo(string arg1, string [argn]…) Description The echo() language construct outputs all the given parameters to the page. Parentheses are optional with one argument and should not be used with multiple arguments. echo "Hello World!";// display Hello World message to user explode() Syntax array explode(string separator, string string) Description The explode() function returns an array of strings where each element is from the string parameter, which is broken out by the separator field. $array1 = explode(",","1,2,3");//$array1 = (1,2,3) flush() Syntax PHP Developer’s Dictionary IT-SC book 164 void flush(void) Description The flush() function tries to force the current output to be returned to the user. The actual results depend on the method PHP is using for delivery. get_html_translation_table Syntax string get_html_translation_table(int table) Description The get_html_translation_table() function, which was added in PHP 4.0b4, returns the translation table that is used internally for htmlspecialchars() and htmlentities() . You should use HTML_ENTITIES OR HTML_SPECIALCHARS to specify which table you want. get_meta_tags() Syntax array get_meta_tags(string filename, int [use_include_path] ) Description The get_meta_tags() function, which was added in PHP 3.04 and PHP 4.0, opens a file specified by filename and parses it looking for any <meta> HTML tags. In the array that is returned, the name property of each meta tag becomes the key and the contents of each meta tag becomes the value. If any special characters exist in the value of the name property, they are substituted with '_' , and the rest of the value is converted to lowercase. Specifying use_include_path as 1 asks PHP to look for the file along the standard include path. htmlentities() Syntax string htmlentities(string string) . [chunklen] , string [end]) Description The chunk_split() function, which was added in PHP 3.0.6 and PHP 4.0, returns string broken up at every chunklen characters by the string end . The optional. from, string to); Description The convert_cyr_string() function, which was added in PHP 3.0.6 and PHP 4.0, returns str converted from one Cyrillic character set to another. The from and. the salt parameter. During installation of PHP, it is determined which encryption functions are in use on the system. If salt is not specified, PHP will auto-generate a salt based on the default