Function fdopen

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Declaration:

unsigned long fdopen(long handle, char type[]);

Description

Associates a stream with a file handle.

obtained from creatdup, dup2, or open. The type of stream must match the mode of the opened handle. The type string used in a call to fdopen is one of the following values:

Value        Description

 

r Open for reading only.

Create for writing.

a Append; open for writing at the end-of-file or create for writing, if the file does not exist.

r+  Open an existing file for update (reading and writing).

w+  Create a new file for update.

a+

To specify that the given file is being opened or created in the text mode, append t to the value of the type string (for example, rt or w+t).

Similarly, to specify the binary mode, append brb or w+b). If t or b is not given in the type string, the mode is controlled by the _fmode global variable. If _fmode is set to O_BINARY, then files will be opened in the binary mode. If _fmode is set to O_TEXT, then files will be opened in the text mode.

Note. The O_* constants are defined in file system.h.

 

   output cannot be directly followed by input without intervening fseekor rewind;

   input cannot be directly followed by output without intervening fseek, rewind, or an input that encounters the end-of-file.

Returned value

On successful completion, fdopen returns the unsigned long identifying the stream. In the event of error, it returns 0.