fopen

FILE *fopen (const char fileName[], const char mode[]);

Purpose

Opens the specified file according to the designated mode. If successful, fopen returns a pointer to the opened stream. When an error occurs, fopen returns NULL and sets errno to a nonzero value.

Parameters

Input
Name	Type	Description
fileName	const char []	Specifies the name of the file to open. Relative pathnames are valid only if relative to the current working directory. Note  Pathnames including backslashes should replace each single backslash with a double backslash to avoid delimiter collision.
mode	const char []	Specifies the mode of reading and writing for the opened file. The possible modes are listed in the following chart: Mode argument Description r Open text file for reading. w Truncate to zero length or create text file for writing. a Append; open or create text file for writing at end-of-file. rb Open binary file for reading. wb Truncate to zero length or create binary file for writing. ab Append; open or create binary file for writing at end-of-file. r+ Open text file for reading and writing. w+ Truncate to zero length or create text file for reading and writing. a+ Append; open or create text file for reading and appending. rb+ Open binary file for reading and writing. wb+ Truncate to zero length or create binary file for reading and writing. ab+ Append; open or create binary file for reading and appending.

Return Value

Additional Information

Library: ANSI C Library

Include file: ansi_c.h

LabWindows/CVI compatibility: LabWindows/CVI 3.0 and later