PHP Developer’s Dictionary IT-SC book 355 2 ( 010 ) Write 3(011) Write and execute 4(100) Read 5 ( 101 ) Read and execute 6(110) Read and write 7(111) Read, write, and execute Table 9.4. Permissions Returned by fileperms() on a Windows System Mode Permission 7(111) Execute—files with a .exe or .bat extension 6(110) Write—normal files 4(100) Read—files with the read-only attribute Note The results of this function are cached by PHP. Any subsequent calls to fileperms() will return the same results even if the environment has changed. The cache is cleared through the clearstatcache() function. filesize() Syntax int filesize(string filename); Description The filesize() function returns the size, in bytes, of the file specified in filename . This function returns false, 0 , if an error is encountered. Note The results of this function are cached by PHP. Any subsequent calls to filesize() will return the same results even if the environment has changed. The cache is cleared through the clearstatcache() function. filetype() Syntax PHP Developer’s Dictionary IT-SC book 356 string filetype(string filename); Description The filetype() function returns the type of the file specified in filename . The file types returned are fifo, char, dir, block, link, file, and unknown. In Windows, this function returns either file or directory. This function returns false, 0 , if an error is encountered. Note The results of this function are cached by PHP. Any subsequent calls to filetype() will return the same results even if the environment has changed. The cache is cleared through the clearstatcache() function. flock() Syntax bool flock(int fp, int operation); Description The flock() function locks the file referenced by fp . This function uses a method of locking that requires all other programs to lock the file in the same way. The methods of locking the file are listed in Table 9.5 . Table 9.5. Operation Parameters Used by the flock() Function Function Operation Binary Shared lock 1 001 Exclusive lock 2 010 Release a lock 3 011 Shared lock without blocking 5 101 Exclusive lock without blocking 6 110 Note The flock() function works on Windows platforms and UNIX platforms. PHP Developer’s Dictionary IT-SC book 357 The flock() function returns true, 1 , if the operation is successful. fopen() Syntax int fopen(string filename , string mode , int [use_include_path] ); Description The fopen() function opens the file specified by filename and a pointer to the file is returned. The mode defines the mode in which the file will be opened. The mode options are listed in Table 9.6 . Table 9.6. Modes for the fopen() Function mode Description r Opens the file in read-only mode and places the file pointer, fp at the beginning of the file. r+ Opens the file in read/write mode and places the file pointer, fp , at the beginning of the file. w Creates a new file in write mode and places the file pointer, fp , at the beginning of the file. If a file exists, it is overwritten with the new file. w+ Creates a new file in read/write mode and places the file pointer, fp , at the beginning of the file. If the file exists, it is overwritten with the new file. a Opens the file in write mode and places the file pointer, fp , at the end of the file. If the file does not exist, it will be created. a+ Opens the file in read/write mode and places the file pointer, fp , at the end of the file. If the file does not exist, it will be created. If filename begins with "http://" , an HTTP 1.0 connection will be opened to the URL and the file pointer will be placed at the beginning of the response text. If filename begins with "ftp://", an FTP connection will be opened to the specified server and the file pointer will be placed at the beginning of the requested file. Note An error will be returned if the FTP server does not support passive mode. The optional parameter use_include_path can be set to "1" if you want to use the include_path to search for the file. fpassthru() PHP Developer’s Dictionary IT-SC book 358 Syntax int fpassthru(int fp); Description The fpassthru() function reads the file pointed to by fp and writes the file to standard out, which is usually the browser. The file is read until End of File, EOF. This function returns true, 1 , if the function is successful. fputs() Syntax int fputs(int fp, string str, int [length]); Description The fputs() function is identical to the fwrite() function. It writes the contents of string to the file defined by fp . The length parameter is optional and if it is not specified, the entire string will be written; otherwise, writing will stop after length bytes are written. This function returns false, 0 , if an error occurred. fread() Syntax string fread(int fp, int length); Description The fread() function reads length bytes from the file referenced by fp . Reading stops when length bytes have been read or EOF is reached, whichever comes first. fseek() Syntax int fseek(int fp, int offset); PHP Developer’s Dictionary IT-SC book 359 Description The fseek() function sets the file pointer, fp , to offset bytes from the start of the file. Note The fseek() function will not return an error if you seek past the end of the file, EOF. ftell() Syntax int ftell(int fp); Description The ftell() function returns the position of the file pointer referenced by fp . The function returns false, 0 , if it is not successful. fwrite() Syntax int fwrite(int fp, string string, int [length]); Description The fwrite() function writes the contents of string to the file defined by fp . The length parameter is optional and if it is not specified, the entire string will be written; otherwise, writing will stop after length bytes are written. set_file_buffer() Syntax int fwrite(int fp, int buffer); . PHP Developer’s Dictionary IT-SC book 355 2 ( 010 ) Write 3(011) Write and execute 4(100) . 4(100) Read—files with the read-only attribute Note The results of this function are cached by PHP. Any subsequent calls to fileperms() will return the same results even if the environment. returns false, 0 , if an error is encountered. Note The results of this function are cached by PHP. Any subsequent calls to filesize() will return the same results even if the environment has