Dynamic variable name 4

[TSch]

Hi folks,

again I'm trying to write a shell script and again I'm facing a problem ...

What I'd like to do is the following:

Counter=0
while [ $Counter -le 3 ];
do
InputX=$(cat /tmp/lst$Counter | awk '{print $1}')
Counter=`expr $Counter + 1`
done

Here's the tricky part:
I don't want the variable to be named InputX !
It's supposed to change according to the $Counter value so that it looks like this:

$Counter=0 -> Variable is supposed to be named Input1
$Counter=1 -> Variable is supposed to be named Input2
... and so on

What I tried was the following:

Input$Counter=$(cat /tmp/lst$Counter | awk '{print $1}')

But that's not working ...
What would be the correct approach here ?

Regards
Thomas

 

[Ogzilal]

Hi, think eval if you want some pointer behaviour that works in two times

Counter=0
while [ $Counter -le 3 ];
do
        eval X=Input$Counter
        echo $X
        eval $X=$(cat /tmp/lst$Counter | awk '{print $1}')
        eval Y=\$Input$Counter
        echo $Y
        Counter=`expr $Counter + 1`
done

 

[Ogzilal]

Same code with reuse X variable

Counter=0
while [ $Counter -le 3 ];
do
        eval X=Input$Counter
        echo $X
        eval $X=$(cat /tmp/lst$Counter | awk '{print $1}')
        eval Y=\$$X
        echo $Y
        Counter=`expr $Counter + 1`
done

 

[feherke]

Hi

Why not use an array ?

[navy]Counter[/navy][teal]=[/teal][purple]0[/purple]
[b]while[/b] [teal][[/teal] [navy]$Counter[/navy] -le [purple]3[/purple] [teal]];[/teal] [b]do[/b]
  Input[highlight][teal][[/teal][navy]Counter[/navy][teal]][/teal][/highlight][teal]=[/teal][navy]$([/navy]cat /tmp/lst[navy]$Counter[/navy] [teal]|[/teal] awk [green][i]'{print $1}'[/i][/green][teal])[/teal]
  [navy]Counter[/navy][teal]=[/teal]`expr [navy]$Counter[/navy] [teal]+[/teal] [purple]1[/purple]`
[b]done[/b]

No idea what shall are you using, but I would prefer C-like syntax :

[navy]Counter[/navy][teal]=[/teal][purple]0[/purple]
[b]while[/b] [teal](([/teal] Counter[teal]<=[/teal][purple]3[/purple] [teal]));[/teal] [b]do[/b]
  Input[teal][[/teal]Counter[teal]]=[/teal][navy]$([/navy]cat /tmp/lst[navy]$Counter[/navy] [teal]|[/teal] awk [green][i]'{print $1}'[/i][/green][teal])[/teal]
  [teal](([/teal] Counter[teal]++[/teal] [teal]))[/teal]
[b]done[/b]

Feherke.

http://free.rootshell.be/~feherke/

 

[PHV]

$Counter=0 -> Variable is supposed to be named Input1
What about this ?

Counter=0
while [ $Counter -le 3 ]; do
  X=$(awk '{print $1}' /tmp/lst$Counter)
  ((Counter+=1))
  eval Input$Counter="$X"
done

Hope This Helps, PH.
FAQ219-2884
FAQ181-2886

 

[stefanwagner]

There is a for-loop hiding in the code.

for (( counter=0; counter < 4; ++counter )); do
  input[counter]=$(cat /tmp/lst$counter | awk '{print $1}')
done

don't visit my homepage:

http://home.arcor.de/hirnstrom/minis/index.html

 

[TSch]

Folks, you're great !
Thanks a lot for all the input ...