pipe command problem 1

[vlz]

Hi,
I have a following script:
--------------------------------------------------
#!/bin/ksh
function start{
var=abc
echo "in function var=$var"
}

start | tee log
echo "in program var=$var"
--------------------------------------------------
This is the output I get:
in function var=abc
in program var=
(i.e. get empty value for var)

When I remove "| tee log"
I get the proper output:

in function var=abc
in program var=abc

How can you explain and fix it?

Thanks in advance,
Vadim

 

[modemer]

I don't think this is a fix, but a workaround depends how complicate with your requirement:

start > log
cat log

I am also wondering why pipe could cause this issue.

 

[xmb]

This happens due you define your var 'globally' default, theres keyword named 'local' to define functions intern in functions

foo() { bar=hiya; echo $bar; }

. Mac for productivity
.. Linux for developement
... Windows for solitaire

 

[xmb]

Heh sorry, foo() { local bar=hiya; echo $bar; }

 

[PHV]

Calling a function with I/O redirection spawns the function in a subshell and thus another instance of the var variable.
Here the proof of concept:
#!/bin/ksh
function start{
var=abc
echo "in function var=$var"
}
start | tee log
echo "in program var=$var should be empty"
(start
echo "in program var=$var shouldn't be empty"
) | tee log

Hope This Helps, PH.
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