teeing parent+childs output

[-H]

Hi,

I have a "parent" C program that forks off a "child" C program.
Both the parent and the child print information to both stdout and
stderr.

I would like to redirect the parent and childs output to both stdout
and an output logfile (in effect, a "tee" like behavior).

I've tried several things with pipes and freopens, but I always seem
to get data out of synch.

Any help on this would be greatly appreciated!
Please cc replies to (e-mail address removed).
Thanks in advance.

- H

 

[Derk Gwen]

(e-mail address removed) (-H) wrote:
# Hi,
#
# I have a "parent" C program that forks off a "child" C program.
# Both the parent and the child print information to both stdout and
# stderr.
#
# I would like to redirect the parent and childs output to both stdout
# and an output logfile (in effect, a "tee" like behavior).
#
# I've tried several things with pipes and freopens, but I always seem
# to get data out of synch.

Each process has its own buffers. To force output to a device, you need to use
fflush or turn off bufferring with setvbuf. This can slow the program down.

 

[Bryan Donlan]

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Hi,

I have a "parent" C program that forks off a "child" C program.
Both the parent and the child print information to both stdout and
stderr.

forking isn't in the ISO C specification. Try comp.unix.programmer.
- --
Freenet distribution not available
You're not an alcoholic unless you go to the meetings.

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[Jack Klein]

(e-mail address removed) (-H) wrote:
# Hi,
#
# I have a "parent" C program that forks off a "child" C program.
# Both the parent and the child print information to both stdout and
# stderr.
#
# I would like to redirect the parent and childs output to both stdout
# and an output logfile (in effect, a "tee" like behavior).
#
# I've tried several things with pipes and freopens, but I always seem
# to get data out of synch.

Each process has its own buffers. To force output to a device, you need to use
fflush or turn off bufferring with setvbuf. This can slow the program down.

Can you cite the section in either the C or C++ standard that defines
what each process has? If not, don't post this drivel here.

--
Jack Klein
Home: http://JK-Technology.Com
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