php r, r+, w, w+, a, a+ file handling
| 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 the file is preserved. The 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 the file already exists |
| r+ | Open a file for reading/write. File pointer starts at the beginning of the file |
| w+ | Open a file for reading/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 reading/write. The existing data in the file is preserved. The 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 reading/write. Returns FALSE and an error if the file already exists |
When you open the file do you want to create the file, then write to it or do you want to open the file and append to it?
For creating/writing/reading use w+
For opening/appending/reading use r+
For opening/appending/reading use r+
“r”
Open a file for reading. The file must exist.
Open a file for reading. The file must exist.
“w”
Create an empty file for writing. If a file with the same name already exists its content is erased and the file is treated as a new empty file.
Create an empty file for writing. If a file with the same name already exists its content is erased and the file is treated as a new empty file.
“a”
Append to a file. Writing operations append data at the end of the file. The file is created if it does not exist.
Append to a file. Writing operations append data at the end of the file. The file is created if it does not exist.
“r+”
Open a file for update both reading and writing. The file must exist.
Open a file for update both reading and writing. The file must exist.
“w+”
Create an empty file for both reading and writing. If a file with the same name already exists its content is erased and the file is treated as a new empty file.
Create an empty file for both reading and writing. If a file with the same name already exists its content is erased and the file is treated as a new empty file.
“a+”
Open a file for reading and appending. All writing operations are performed at the end of the file, protecting the previous content to be overwritten. You can reposition the internal pointer anywhere in the file for reading, but writing operations will move it back to the end of the file. The file is created if it does not exist.
Open a file for reading and appending. All writing operations are performed at the end of the file, protecting the previous content to be overwritten. You can reposition the internal pointer anywhere in the file for reading, but writing operations will move it back to the end of the file. The file is created if it does not exist.
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