Filesystem basename return filename component of path string basename string path Given a string containing a path to a file, this function will return the base name of the file. On Windows, both slash (/) and backslash (\) are used as path separator character. In other environments, it is the forward slash (/). $path = "/home/httpd/html/index.php3"; $file = basename($path); // $file is set to "index.php3" See also: dirname chgrp change file group int chgrp string filename mixed group Attempts to change the group of the file filename to group. Only the superuser may change the group of a file arbitrarily; other users may change the group of a file to any group of which that user is a member. Returns true on success; otherwise returns false. On Windows, does nothing and returns true. See also chown and chmod. chmod change file mode int chmod string filename int mode Attempts to change the mode of the file specified by filename to that given in mode. Note that mode is not automatically assumed to be an octal value. To ensure the expected operation, you need to prefix mode with a zero (0): chmod( "/somedir/somefile", 755 ); // decimal; probably incorrect chmod( "/somedir/somefile", 0755 ); // octal; correct value of mode Returns true on success and false otherwise. See also chown and chgrp. chown change file owner int chown string filename mixed user Attempts to change the owner of the file filename to user user. Only the superuser may change the owner of a file. Returns true on success; otherwise returns false. On Windows, does nothing and returns true. See also chown and chmod. clearstatcache clear file stat cache void clearstatcache Invoking the stat or lstat system call on most systems is quite expensive. Therefore, the result of the last call to any of the status functions (listed below) is stored for use on the next such call using the same filename. If you wish to force a new status check, for instance if the file is being checked many times and may change or disappear, use this function to clear the results of the last call from memory. This value is only cached for the lifetime of a single request. Affected functions include stat, lstat, file_exists, is_writeable, is_readable, is_executable, is_file, is_dir, is_link, filectime, fileatime, filemtime, fileinode, filegroup, fileowner, filesize, filetype, and fileperms. copy copy file int copy string source string dest Makes a copy of a file. Returns true if the copy succeeded, false otherwise. if (!copy($file, $file.'.bak')) { print("failed to copy $file...<br>\n"); } See also: rename delete a dummy manual entry void delete string file This is a dummy manual entry to satisfy those people who are looking for unlink or unset in the wrong place. See also: unlink to delete files, unset to delete variables. dirname return directory name component of path string dirname string path Given a string containing a path to a file, this function will return the name of the directory. On Windows, both slash (/) and backslash (\) are used as path separator character. In other environments, it is the forward slash (/). $path = "/etc/passwd"; $file = dirname($path); // $file is set to "/etc" See also: basename diskfreespace return available space in directory float diskfreespace string directory Given a string containing a directory, this function will return the number of bytes available on the corresponding disk. $df = diskfreespace("/"); // $df contains the number of bytes available on "/" fclose close an open file pointer int fclose int fp The file pointed to by fp is closed. Returns true on success and false on failure. The file pointer must be valid, and must point to a file successfully opened by fopen or fsockopen. feof test for end-of-file on a file pointer int feof int fp Returns true if the file pointer is at EOF or an error occurs; otherwise returns false. The file pointer must be valid, and must point to a file successfully opened by fopen, popen, or fsockopen. fgetc get character from file pointer string fgetc int fp Returns a string containing a single character read from the file pointed to by fp. Returns FALSE on EOF (as does feof). The file pointer must be valid, and must point to a file successfully opened by fopen, popen, or fsockopen. See also fread, fopen, popen, fsockopen, and fgets. fgetcsv get line from file pointer and parse for CSV fields array fgetcsv int fp int length string delimiter Similar to fgets() except that fgetcsv() parses the line it reads for fields in CSV format and returns an array containing the fields read. The field delimiter is a comma, unless you specifiy another delimiter with the optional third parameter. fp must be a valid file pointer to a file successfully opened by fopen, popen, or fsockopen length must be greater than the longest line to be found in the CSV file (allowing for trailing line-end characters). fgetcsv() returns false on error, including end of file. NB A blank line in a CSV file will be returned as an array comprising just one single null field, and will not be treated as an error. $row=1; $fp = fopen("test.csv","r"); while ($data = fgetcsv($fp,1000, ",")) { $num = count($data); print "<p> $num fields in line $row: <br>"; $row++; for ( $c=0; $c<$num; $c++ ) print $data[$c] . "<br>"; } fclose($fp); fgets get line from file pointer string fgets int fp int length Returns a string of up to length - 1 bytes read from the file pointed to by fp. Reading ends when length - 1 bytes have been read, on a newline (which is included in the return value), or on EOF (whichever comes first). If an error occurs, returns false. Common Pitfalls: People used to the 'C' semantics of fgets should note the difference in how EOF is returned. The file pointer must be valid, and must point to a file successfully opened by fopen, popen, or fsockopen. A simple example follows: $fd = fopen("/tmp/inputfile.txt", "r"); while (!feof($fd)) { $buffer = fgets($fd, 4096); echo $buffer; } fclose($fd); See also fread, fopen, popen, fgetc, and fsockopen. fgetss get line from file pointer and strip HTML tags string fgetss int fp int length string allowable_tags Identical to fgets, except that fgetss attempts to strip any HTML and PHP tags from the text it reads. You can use the optional third parameter to specify tags which should not be stripped. allowable_tags was added in PHP 3.0.13, PHP4B3. See also fgets, fopen, fsockopen, popen, and strip_tags. file read entire file into an array array file string filename int use_include_path Identical to readfile, except that file returns the file in an array. Each element of the array corresponds to a line in the file, with the newline still attached. You can use the optional second parameter and set it to "1", if you want to search for the file in the include_path, too. See also readfile, fopen, and popen. file_exists Check whether a file exists. int file_exists string filename Returns true if the file specified by filename exists; false otherwise. The results of this function are cached. See clearstatcache for more details. fileatime get last access time of file int fileatime string filename Returns the time the file was last accessed, or false in case of an error. The results of this function are cached. See clearstatcache for more details. filectime get inode change time of file int filectime string filename Returns the time the file was last changed, or false in case of an error. The results of this function are cached. See clearstatcache for more details. filegroup get file group int filegroup string filename Returns the group ID of the owner of the file, or false in case of an error. The results of this function are cached. See clearstatcache for more details. fileinode get file inode int fileinode string filename Returns the inode number of the file, or false in case of an error. The results of this function are cached. See clearstatcache for more details. filemtime get file modification time int filemtime string filename Returns the time the file was last modified, or false in case of an error. The results of this function are cached. See clearstatcache for more details. fileowner get file owner int fileowner string filename Returns the user ID of the owner of the file, or false in case of an The results of this function are cached. See clearstatcache for more details. error. fileperms get file permissions int fileperms string filename Returns the permissions on the file, or false in case of an error. The results of this function are cached. See clearstatcache for more details. filesize get file size int filesize string filename Returns the size of the file, or false in case of an error. The results of this function are cached. See clearstatcache for more details. filetype get file type string filetype string filename Returns the type of the file. Possible values are fifo, char, dir, block, link, file, and unknown. Returns false if an error occurs. The results of this function are cached. See clearstatcache for more details. flock portable advisory file locking bool flock int fp int operation PHP supports a portable way of locking complete files in an advisory way (which means all accessing programs have to use the same way of locking or it will not work). flock operates on fp which must be an open file pointer. operation is one of the following values: To acquire a shared lock (reader), set operation to 1. To acquire an exclusive lock (writer), set operation to 2. To release a lock (shared or exclusive), set operation to 3. If you don't want flock to block while locking, add 4 to operation. flock allows you to perform a simple reader/writer model which can be used on virtually every platform (including most Unices and even Windows). flock returns true on success and false on error (e.g. when a lock could not be acquired). fopen open file or URL int fopen string filename string mode int use_include_path If filename begins with "http://" (not case sensitive), an HTTP 1.0 connection is opened to the specified server and a file pointer is returned to the beginning of the text of the response. Does not handle HTTP redirects, so you must include trailing slashes on directories. If filename begins with "ftp://" (not case sensitive), an ftp connection to the specified server is opened and a pointer to the requested file is returned. If the server does not support passive mode ftp, this will fail. You can open files for either reading and writing via ftp (but not both simultaneously). If filename begins with anything else, the file will be opened from the filesystem, and a file pointer to the file opened is returned. If the open fails, the function returns false. mode may be any of the following: 'r' - Open for reading only; place the file pointer at the beginning of the file. 'r+' - Open for reading and writing; place the file pointer at the beginning of the file. 'w' - Open for writing only; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it. 'w+' - Open for reading and writing; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it. 'a' - Open for writing only; place the file pointer at the end of the file. If the file does not exist, attempt to create it. 'a+' - Open for reading and writing; place the file pointer at the end of the file. If the file does not exist, attempt to create it. As well, mode may contain the letter 'b'. This is useful only on systems which differentiate between binary and text files (i.e., it's useless on Unix). If not needed, this will be ignored. You can use the optional third parameter and set it to "1", if you want to search for the file in the include_path, too. $fp = fopen("/home/rasmus/file.txt", "r"); $fp = fopen("http://www.php.net/", "r"); $fp = fopen("ftp://user:password@example.com/", "w"); If you are experiencing problems with reading and writing to files and you're using the server module version of PHP, remember to make sure that the files and directories you're using are accessible to the server process. On the Windows platform, be careful to escape any backslashes used in the path to the file, or use forward slashes. $fp = fopen("c:\\data\\info.txt", "r"); See also fclose, fsockopen, and popen. fpassthru output all remaining data on a file pointer int fpassthru int fp Reads to EOF on the given file pointer and writes the results to standard output. If an error occurs, fpassthru returns false. The file pointer must be valid, and must point to a file successfully opened by fopen, popen, or fsockopen. The file is closed when fpassthru is done reading it (leaving fp useless). If you just want to dump the contents of a file to stdout you may want to use the readfile, which saves you the fopen call. See also readfile, fopen, popen, and fsockopen fputs write to a file pointer int fputs int fp string str int length fputs is an alias to fwrite, and is identical in every way. Note that the length parameter is optional and if not specified the entire string will be written. fread Binary-safe file read string fread int fp int length fread reads up to length bytes from the file pointer referenced by fp. Reading stops when length bytes have been read or EOF is reached, whichever comes first. // get contents of a file into a string $filename = "/usr/local/something.txt"; $fd = fopen( $filename, "r" ); $contents = fread( $fd, filesize( $filename ) ); fclose( $fd ); See also fwrite, fopen, fsockopen, popen, fgets, fgetss, file, and fpassthru. fseek seek on a file pointer int fseek int fp int offset Sets the file position indicator for the file referenced by fp to offset bytes into the file stream. Equivalent to calling (in C) fseek( fp, offset, SEEK_SET ). Upon success, returns 0; otherwise, returns -1. Note that seeking past EOF is not considered an error. May not be used on file pointers returned by fopen if they use the "http://" or "ftp://" formats. See also ftell and rewind. ftell tell file pointer read/write position int ftell int fp Returns the position of the file pointer referenced by fp; i.e., its offset into the file stream. If an error occurs, returns false. The file pointer must be valid, and must point to a file successfully opened by fopen or popen. See also fopen, popen, fseek and rewind. fwrite Binary-safe file write int fwrite int fp string string int length fwrite writes the contents of string to the file stream pointed to by fp. If the length argument is given, writing will stop after length bytes have been written or the end of string is reached, whichever comes first. Note that if the length argument is given, then the magic_quotes_runtime configuration option will be ignored and no slashes will be stripped from string. See also fread, fopen, fsockopen, popen, and fputs. set_file_buffer Sets file buffering on the given file pointer int fwrite int fp int buffer set_file_buffer sets the buffering for write operations on the given filepointer fp to buffer bytes. If buffer is 0 then write operations are unbuffered. The function returns 0 on success, or EOF if the request cannot be honored. Note that the default for any fopen with calling set_file_buffer is 8K. See also fopen. is_dir tells whether the filename is a directory bool is_dir string filename Returns true if the filename exists and is a directory. The results of this function are cached. See clearstatcache for more details. See also is_file and is_link. is_executable tells whether the filename is executable bool is_executable string filename Returns true if the filename exists and is executable. The results of this function are cached. See clearstatcache for more details. See also is_file and is_link. is_file tells whether the filename is a regular file bool is_file string filename Returns true if the filename exists and is a regular file. The results of this function are cached. See clearstatcache for more details. See also is_dir and is_link. is_link tells whether the filename is a symbolic link bool is_link string filename Returns true if the filename exists and is a symbolic link. The results of this function are cached. See clearstatcache for more details. See also is_dir and is_file. is_readable tells whether the filename is readable bool is_readable string filename Returns true if the filename exists and is readable. Keep in mind that PHP may be accessing the file as the user id that the web server runs as (often 'nobody'). Safe mode limitations are not taken into account. The results of this function are cached. See clearstatcache for more details. See also is_writeable. is_writeable tells whether the filename is writeable bool is_writeable string filename Returns true if the filename exists and is writeable. The filename argument may be a directory name allowing you to check if a directory is writeable. Keep in mind that PHP may be accessing the file as the user id that the web server runs as (often 'nobody'). Safe mode limitations are not taken into account. The results of this function are cached. See clearstatcache for more details. See also is_readable. link Create a hard link int link string target string link Link creates a hard link. See also the symlink to create soft links, and readlink along with linkinfo. linkinfo Get information about a link int linkinfo string path Linkinfo returns the st_dev field of the UNIX C stat structure returned by the lstat system call. This function is used to verify if a link (pointed to by path) really exists (using the same method as the S_ISLNK macro defined in stat.h). Returns 0 or FALSE in case of error. See also symlink, link, and readlink. mkdir make directory int mkdir string pathname int mode Attempts to create the directory specified by pathname. Note that you probably want to specify the mode as an octal number, which means it should have a leading zero. mkdir("/path/to/my/dir", 0700); Returns true on success and false on failure. See also rmdir. pclose close process file pointer int pclose int fp Closes a file pointer to a pipe opened by popen. The file pointer must be valid, and must have been returned by a successful call to popen. Returns the termination status of the process that was run. See also popen. popen open process file pointer int popen string command string mode Opens a pipe to a process executed by forking the command given by command. Returns a file pointer identical to that returned by fopen, except that it is unidirectional (may only be used for reading or writing) and must be closed with pclose. This pointer may be used with fgets, fgetss, and fputs. If an error occurs, returns false. $fp = popen( "/bin/ls", "r" ); See also pclose. readfile output a file int readfile string filename int use_include_path Reads a file and writes it to standard output. Returns the number of bytes read from the file. If an error occurs, false is returned and unless the function was called as @readfile, an error message is printed. If filename begins with "http://" (not case sensitive), an HTTP 1.0 connection is opened to the specified server and the text of the response is written to standard output. Does not handle HTTP redirects, so you must include trailing slashes on directories. If filename begins with "ftp://" (not case sensitive), an ftp connection to the specified server is opened and the requested file is written to standard output. If the server does not support passive mode ftp, this will fail. If filename begins with neither of these strings, the file will be opened from the filesystem and its contents written to standard output. You can use the optional second parameter and set it to "1", if you want to search for the file in the include_path, too. See also fpassthru, file, fopen, include, require, and virtual. readlink Return the target of a symbolic link string readlink string path Readlink does the same as the readlink C function and returns the contents of the symbolic link path or 0 in case of error. See also symlink, readlink and linkinfo. rename rename a file int rename string oldname string newname Attempts to rename oldname to newname. Returns true on success and false on failure. rewind rewind the position of a file pointer int rewind int fp Sets the file position indicator for fp to the beginning of the file stream. If an error occurs, returns 0. The file pointer must be valid, and must point to a file successfully opened by fopen. See also fseek and ftell. rmdir remove directory int rmdir string dirname Attempts to remove the directory named by pathname. The directory must be empty, and the relevant permissions must permit this. If an error occurs, returns 0. See also mkdir. stat give information about a file array stat string filename Gathers the statistics of the file named by filename. Returns an array with the statistics of the file with the following elements: device inode inode protection mode number of links user id of owner group id owner device type if inode device * size in bytes time of last access time of last modification time of last change blocksize for filesystem I/O * number of blocks allocated * - only valid on systems supporting the st_blksize type--other systems (i.e. Windows) return -1 The results of this function are cached. See clearstatcache for more details. lstat give information about a file or symbolic link array lstat string filename Gathers the statistics of the file or symbolic link named by filename. This function is identical to the stat function except that if the filename parameter is a symbolic link, the status of the symbolic link is returned, not the status of the file pointed to by the symbolic link. Returns an array with the statistics of the file with the following elements: device inode number of links user id of owner group id owner device type if inode device * size in bytes time of last access time of last modification time of last change blocksize for filesystem I/O * number of blocks allocated * - only valid on systems supporting the st_blksize type--other systems (i.e. Windows) return -1 The results of this function are cached. See clearstatcache for more details. symlink Create a symbolic link int symlink string target string link symlink creates a symbolic link from the existing target with the specified name link. See also link to create hard links, and readlink along with linkinfo. tempnam create unique file name string tempnam string dir string prefix Creates a unique temporary filename in the specified directory. If the directory does not exist, tempnam may generate a filename in the system's temporary directory. The behaviour of the tempnam function is system dependent. On Windows the TMP environment variable will override the dir parameter, on Linux the TMPDIR environment variable has precedence, while SVR4 will always use your dir parameter if the directory it points to exists. Consult your system documentation on the tempnam(3) function if in doubt. Returns the new temporary filename, or the null string on failure. $tmpfname = tempnam( "/tmp", "FOO" ); touch set modification time of file int touch string filename int time Attempts to set the modification time of the file named by filename to the value given by time. If the option time is not given, uses the present time. If the file does not exist, it is created. Returns true on success and false otherwise. umask changes the current umask int umask int mask Umask sets PHP's umask to mask & 0777 and returns the old umask. When PHP is being used as a server module, the umask is restored when each request is finished. Umask without arguments simply returns the current umask. unlink Delete a file int unlink string filename Deletes filename. Similar to the Unix C unlink() function. Returns 0 or FALSE on an error. See also rmdir for removing directories.