A better method to open files is with the fopen() function. This function gives you more options than the readfile() function.
We will use the text file, "webdictionary.txt", during the lessons:
The first parameter of fopen() contains the name of the file to be opened and the second parameter specifies in which mode the file should be opened. The following example also generates a message if the fopen() function is unable to open the specified file:
See this example:
The file may be opened in one of the following modes:
| Modes | Description |
|---|---|
| r | Open a file for read only. File pointer starts at the beginning of the file |
| w | Open a file for write only. Erases the contents of the file or creates a new file if it doesn't exist. File pointer starts at the beginning of the file |
| a | Open a file for write only. The existing data in file is preserved. File pointer starts at the end of the file. Creates a new file if the file doesn't exist |
| x | Creates a new file for write only. Returns FALSE and an error if file already exists |
| r+ | Open a file for read/write. File pointer starts at the beginning of the file |
| w+ | Open a file for read/write. Erases the contents of the file or creates a new file if it doesn't exist. File pointer starts at the beginning of the file |
| a+ | Open a file for read/write. The existing data in file is preserved. File pointer starts at the end of the file. Creates a new file if the file doesn't exist |
| x+ | Creates a new file for read/write. Returns FALSE and an error if file already exists |
The fread() function reads from an open file.
The first parameter of fread() contains the name of the file to read from and the second parameter specifies the maximum number of bytes to read.
The following PHP code reads the "webdictionary.txt" file to the end:
The fclose() function is used to close an open file.
The fclose() requires the name of the file (or a variable that holds the filename) we want to close:
The fopen() function is also used to create a file. Maybe a little confusing, but in PHP, a file is created using the same function used to open files.
If you use fopen() on a file that does not exist, it will create it, given that the file is opened for writing (w) or appending (a).
See this example:
The fwrite() function is used to write to a file.
The first parameter of fwrite() contains the name of the file to write to and the second parameter is the string to be written.
See this example:
