[cs631apue] HW3 grades
Jan Schaumann
jschauma at stevens.edu
Sat Nov 4 15:29:29 EDT 2017
Hello,
I've sent out HW3 grades.
As mentioned in class, I wasn't so much looking for a perfectly working
program (although some submissions were just that), but rather for the
correct approach to the problem:
- create two pipes
- fork
- dup2 stdout and stderr onto the write-ends of the pipe
- exec argv+1
- read from read-ends of the pipes and count++ on '\n'
Using popen(3) can't work, since you can't separately count stdout and
stderr from the child process.
Invoking 'wc -l' in one of the child processes doesn't get you the count
of stderr, so that fails, too. (And is expensive, in comparison.)
-Jan
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