🚀 go-pugleaf

  I have written a filter program,  one which reads from standard
input and writes to standard output.  The output works OK when
printing to the console, or when redirected via the shell to a file,
but fails when piped into the standard input of another program,
such as 'cat'.

  I am running SunOS 4.1, using libg++ 2.3 (I believe).  The test 
program below tries to act like cat, copying its input verbatim to
the output.

	#include <String.h>

	int main (int argc, char ** argv, char **env)
	{
	    String line;
	     // keep terminator, or cannot tell eof
	    while (readline(cin,line,'\n',0)) cout << line ;
	}

  Call the program above 'acat'.  I can do the following tests:

	cat foo.txt | cat		- prints foo.txt
	cat foo.txt | acat		- prints foo.txt
	cat foo.txt | acat | cat	- NO output!
	cat foo.txt | cat | cat		- prints foo.txt
	cat foo.txt | acat > bar.txt	- bar.txt contains foo.txt

  Other variations convince me that I cannot pipe the output of
this program into itself or any other "filter" program. What gives?
This is a very disquieting thing to have happen.

  BTW, the executable for this program is 524K.  Also disquieting.

-Sean

	  

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Sean Burke			sean@netcom.com