FILE opening mode of fopen() in C language

In fopen(), it is necessary to provide opening mode with the file name. Opening mode can control operation performed on opened text file or binary file.

File opening mode and their purpose are represented in following tables :-
fopen() में file के नाम के साथ उसका ओपनिंग मोड देना आवश्यक होता है, ओपनिंग मोड यह नियंत्रित करता  है कि खुली हुई टेक्स्ट या बाइनरी फाइल पर कौन-कौन से ऑपरेशन किये जायेंगे।

फाइल ओपनिंग मोड एवं उनके उद्देश्य को निम्न तालिका में दर्शाया गया है-       

TEXT FILE OPENING MODES
S.No.	Opening mode	Role	If the file already exit	If the file does not exit
1)	r  (पढ़ना)	reading a file	open a file read only not write	operation fail return NULL
2)	w (लिखना)	writing a file and save	over write existing it means previous file content are replace with new content	create a file write and save it
3)	a  (संलग्न करना)	appending text into file	new information is added to the file after EOF	create a new file and write
4)	r+	reading +writing a file (update)	new text is written after existing file data	creates a new file
5)	w+	reading +writing a file	previous file data will be erased or delete first and then new data is written at the begaining of the file	creates a new file
6)	a+	reading +appending a file	new data is written after EOF and we can read previous data also	creates a new file

BINARY FILE OPENING MODES
S.No.	Opening mode	Role	If the binary file already exit	If the binary file does not exit
1)	rb	reading a binary file	open a binary file read only not write	operation fail return NULL
2)	wb	writing a binary file and save	over write existing it means previous binary file content are replace with new content	create a binary file write and save it
3)	ab	appending binary bytes into binary file	new information is added to the binary file after EOF	create a new binary file and write
4)	rb+	reading +writing a binary file (update)	new data is written after existing binary file data	creates a new binary file
5)	wb+	reading +writing a binary file	previous binary file data will be erased or delete first and then new data is written at the begining of the binary file	creates a new binary file
6)	ab+	reading +appending a binary file	new data is written after EOF and we can read previous data also	creates a new binary file