| FTP is great for transferring files back and forth on the Internet, and you can use FTP from PHP. In order to use FTP functions, you should add the --enable-ftp option when installing PHP 4. The Windows version of PHP has built-in support for this extension. Using FTP is not hard. To connect to an FTP server, you use ftp_connect: ftp_connect(string host [, int port [, int timeout]])
This function opens an FTP connection to the specified host (note that host shouldn't have any trailing slashes and shouldn't be prefixed with ftp://). The port parameter specifies an alternate port to connect to; if it is omitted or set to zero, then the default FTP port, 21, will be used. The timeout parameter specifies the timeout for all subsequent network operations. If omitted, the default value is 90 seconds. This function returns an FTP stream on success or FALSE on error. After you connect with ftp_connect, you must log in with ftp_login, which you use this way: ftp_login(resource ftp_stream, string username, string password)
This function passes your username and password to the FTP server, and it returns trUE on success or FALSE on failure. For example, here's how you can connect to and log into an FTP server: <?php $connect = ftp_connect("ftp.ispname.com"); $result = ftp_login($connect, $username, $password); . . .
We'll use this kind of code to connect to FTP servers in the following chunks. Besides ftp_connect and ftp_login, there are plenty of other FTP functions in PHP; here's a starter list: ftp_alloc. Allocates space for a file to be uploaded ftp_cdup. Changes to the parent directory ftp_chdir. Changes directories on an FTP server ftp_chmod. Sets permissions on a file via FTP ftp_close. Closes an FTP connection ftp_connect. Opens an FTP connection ftp_delete. Deletes a file on the FTP server ftp_exec. Requests execution of a program on the FTP server ftp_fget. Downloads a file from the FTP server and saves to an open file ftp_fput. Uploads from an open file to the FTP server ftp_get_option. Retrieves run-time behaviors of the current FTP stream ftp_get. Downloads a file from the FTP server ftp_login. Logs in to an FTP connection ftp_mdtm. Returns the last modified time of the given file ftp_mkdir. Creates a directory ftp_nb_continue. Continues retrieving/sending a file ftp_nb_fget. Retrieves a file from the FTP server and writes it to an open file ftp_nb_fput. Stores a file from an open file to the FTP server ftp_nb_get. Retrieves a file from the FTP server and writes it to a local file ftp_nb_put. Stores a file on the FTP server ftp_nlist. Returns a list of files in the given directory ftp_put. Uploads a file to the FTP server ftp_pwd. Returns the current directory name ftp_quit. An alias of ftp_close ftp_raw. Sends an arbitrary command to an FTP server ftp_rawlist. Returns a detailed list of files in the given directory ftp_rename. Renames a file on the FTP server ftp_rmdir. Removes a directory ftp_set_option. Sets miscellaneous run-time FTP options ftp_site. Sends a SITE command to the server ftp_size. Returns the size of the given file ftp_ssl_connect. Opens a secure SSL-FTP connection ftp_systype. Returns the system type identifier of the remote FTP server
We'll put a number of these functions to work in the following chunks. | 