Open for reading.
If the file does not exist, fopen() returns NULL.
If the file exists, its contents are overwritten. If the file
w
Open for writing.
does not exist, it will be created.
Open for append. i.e, Data is
a
If the file does not exists, it will be created.
added to end of file.
Open for both reading and
r+
If the file does not exist, fopen() returns NULL.
writing.
Opening Modes in Standard I/O
File Mode Meaning Of Mode