C stdio fopen() Function
❮ C stdio Library
Example
Create a file:
FILE *fptr;
// Create a file
fptr = fopen("filename.txt", "w");
// Close the file
fclose(fptr);
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Definition and Usage
The fopen() function opens a file and returns a special FILE pointer which is used in other functions that read and write into files.
The fopen() function is defined in the <stdio.h> header file.
Syntax
fopen(const char * filename, const char * mode);
Parameter Values
| Parameter |
Description |
| filename |
Required. A string containing the path to the file.
|
| mode |
Required. A string describing how the file will be used. It can be one of the following
w - Open for writing only. Clears all of the content of the file. If the file does not exist it will be created.
a - Open for writing only. Only writes to the end of the file. If the file does not exist it will be created.
r - Open for reading only. If the file does not exist then a NULL pointer is returned.
w+ - Open for reading and writing. Clears all of the content of the file. If the file does not exist it will be created.
a+ - Open for reading and writing. Only writes to the end of the file. If the file does not exist it will be created.
r+ - Open for reading and writing. If the file does not exist then a NULL pointer is returned.
An additional character "b" can be added to treat the file as a binary file. For example, r+b.
|
Technical Details
| Returns: |
A FILE pointer which can be used by other file handling functions. |
❮ C stdio Library