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stdout and stderr in Linux

Posted on 1998-04-28
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Last Modified: 2013-12-26
UNIXer,

Can I redirect the stdout and stderr to a temporary file by the following code ?
  filename=tmpnam(0);
  freopen(filename, "w", stderr);
  freopen(filename, "w", stdout);

But, how come I cannot print characters to the original stdout and stderr by doing the following code ?
  stdout=fopen("/dev/stdout", "w");
  stderr=fopen("/dev/stderr", "w");

Anyway, how can I achieve it ?

Andrew
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Question by:andrewyu
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seedy earned 0 total points
ID: 1292544
By default stdin and stdout will be pointing to the terminal.
So, when you want to restore them, you would do
   stdout = fopen("/dev/tty", "w");
   stderr = fopen("/dev/tty", "w");
Hope this helps.
PS: Andrewyu, why is that you never grade answers?
   
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Expert Comment

by:seedy
ID: 1292545
BTW, there is no device like '/dev/stdout' or '/dev/stderr'.
From man pages for 'tty':
The file '/dev/tty' is, in each process, a synonym for the
control terminal associated with the process group of that
process, if any.
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Expert Comment

by:sinu
ID: 1292546
Go thru a good book on unix file io.

 there is no device like '/dev/stdout' or '/dev/stderr'.
From man pages for 'tty':
The file '/dev/tty' is, in each process, a synonym for the
control terminal associated with the process group of that
process, if any.
0
 
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Expert Comment

by:seedy
ID: 1292547
Sinu,
Hope you did not mean to do that!
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