I just dont understand why the escape of double-quotes would cause this, because in my logic:
Lets say, in the file.dat is only this:
my name is ratna
Then, it will be:
Code:
eval echo ""my name is ratna""
this is so wierd right? I dont want to just know that the one version causes a, the other one causes b. I really want to know how eval works.. Is it really that difficult?
Regards,
Ratna
No it isn't difficult. With:
Code:
eval echo "`cat $var`"
the eval processes the command line yielding:
Code:
echo echo "this is step 1"
date
and then passes those commands to the shell yielding:
Code:
echo this is step 1
<<<output from date command>>>
but with:
Code:
eval echo "\"`cat $var`\""
the eval processes the command line yielding:
Code:
echo "echo "this is step 1"
date"
and then passes this single echo command to the shell yielding:
Code:
echo this is step 1
date
The escaped quotes from this eval and the quotes inside file were paired together by the shell just as it would if you typed the command:
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Linux s10-1310 2.6.16.53-0.8.PTF.434477.3.TDC.0-smp #1 SMP Fri Aug 31 06:07:27 PDT 2007 x86_64 x86_64 x86_64 GNU/Linux
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04-25-2013
