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Re: EB40 Serial port #1 question.
- To: felixwong at i-technologies dot cc
- Subject: Re: [ECOS] EB40 Serial port #1 question.
- From: Jonathan Larmour <jlarmour at redhat dot com>
- Date: Thu, 11 Oct 2001 18:47:49 +0100
- Cc: ecos-discuss at sources dot redhat dot com
- Organization: Red Hat UK Ltd.
- References: <NFBBLLEDKLLJHLKGHKACEEGFCAAA.felixwong@i-technologies.cc>
felixwong@i-technologies.cc wrote:
>
> Now have no problem in output part using fprintf & other file operations.
> What if I want to have a READ/WRITE device open?
> use "r+w" instead of "rw" or "wr"?
>From a linux man page:
r Open text file for reading. The stream is positioned at
the beginning of
the file.
r+ Open for reading and writing. The stream is positioned at
the beginning of
the file.
w Truncate file to zero length or create text file for
writing. The stream is
positioned at the beginning of the file.
w+ Open for reading and writing. The file is created if it
does not exist,
otherwise it is truncated. The stream is positioned at the
beginning of the
file.
a Open for writing. The file is created if it does not exist.
The stream is
positioned at the end of the file.
a+ Open for reading and writing. The file is created if it
does not exist.
The stream is positioned at the end of the file.
The mode string can also include the letter ``b'' either as a last
character or as
a character between the characters in any of the two-character
strings described
above. This is strictly for compatibility with ANSI X3.159-1989
(``ANSI C'') and
has no effect; the ``b'' is ignored on all POSIX conforming
systems, including
Linux. (Other systems may treat text files and binary files
differently, and
adding the ``b'' may be a good idea if you do I/O to a binary file
and expect that
your program may be ported to non-Unix environments.)
Jifl
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