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#22205
tee bug?
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Your bug report
#22205: tee bug?
which was filed against the coreutils package, has been closed.
The explanation is attached below, along with your original report.
If you require more details, please reply to 22205 <at> debbugs.gnu.org.
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22205: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=22205
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tag 22205 notabug
thanks
On 12/18/2015 06:18 AM, Nacho Esteban wrote:
> Hi team,
>
> I detected an strange behaviour of tee command that may bee a bug.
Not a bug in tee, but intentional behavior of your shell.
>
> Please consider this script snippet
>
> VAR=""
>
> A() {
> VAR="This is my value"
> echo "VAR in $FUNCNAME: $VAR"
> }
>
> BA() {
> A | tee /tmp/kk
You are using a pipeline. Shells implement pipelines by running the
left command (here, the function A) in a subshell. (POSIX also says that
the right command can also be a subshell, but there it is not required;
ksh runs the right command in the current shell, and bash used to run it
in a subshell but new enough bash now has a knob you can turn on to
emulate ksh behavior).
Therefore, all changes to the environment made during the execution of A
are local to that subshell, and are lost as soon as the subshell exits.
> echo "VAR in $FUNCNAME: $VAR"
Thus, here you print the value of $VAR as it was before A ran, since
running A does not affect the current shell.
> In fact if "| tee /tmp/kk" is removed value of VAR is properly visible
> from BA function:
Because then you no longer have a subshell, so now the execution of
function A affects the current shell. Again, not tee's fault. You
could replace it with "| :" and see the same effect.
> This e-mail (including any attachments) is confidential and may be
> privileged or
Such a disclaimer is unenforceable on publically-archived lists, and you
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sending mail to public lists.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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Hi team,
I detected an strange behaviour of tee command that may bee a bug.
Please consider this script snippet
VAR=""
A() {
VAR="This is my value"
echo "VAR in $FUNCNAME: $VAR"
}
BA() {
A | tee /tmp/kk
echo "VAR in $FUNCNAME: $VAR"
}
This is the output when when executed:
$ BA
VAR in A: This is my value
VAR in BA:
I miss the value of VAR inside BA function.
In fact if "| tee /tmp/kk" is removed value of VAR is properly visible
from BA function:
VAR=""
A() {
VAR="This is my value"
echo "VAR in $FUNCNAME: $VAR"
}
BA() {
A
echo "VAR in $FUNCNAME: $VAR"
}
$ BA
VAR in A: This is my value
VAR in BA: This is my value
Many thanks for your priceless effort,
Nacho
*Juan Ignacio Esteban*
Integration Architect & Security Officer | Integration Centre of Expertise
*Walgreens Boots Alliance - Enterprise IT Shared Services - Retail
Pharmacy International & Pharmaceutical Wholesale*
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| 50830
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This bug report was last modified 9 years and 159 days ago.
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