set variables in a for loop 1

[nabana2]

Hi

I am writing a bash script in which i need to set variables in a for loop.
This doesn't seem to work and I'm not sure why it is any different to setting them any where else in the script.

I have tried:

array=(1 2 3 4 5 6 7 8 9); for i in ${array[*]}; do "V$i"="test"; done

but i just get a series of:
-bash: V1=test: command not found

V1="test" would work fine so why cant i do it in a for loop?

Thank you

 

[feherke]

Hi

for i in ${array[*]}; do [red]eval[/red] "V$i=test"; done

[gray]# or[/gray]

for i in ${array[*]}; do [red]export[/red] "V$i=test"; done

Feherke.

http://rootshell.be/~feherke/

 

[nabana2]

Thanks very much Feherke.
I'm half way there.

I am now struggling to use the value of my variable in an if statement.
I haven't been able to find any info on the internet for what I'm trying to do.

My objective is to assign a default value to a set of variables if they have a null value.

for i in V1 V2 V3 V4 V5; do
  eval echo \$$i; 
  if [ -z \$$i ]; then 
    eval "$i=test";
    eval echo \$$i;
  fi;
done

Thank you

 

[feherke]

Hi

Parameter Expansion

[gray]...[/gray]

${parameter:=word}
Assign Default Values. If parameter is unset or
null, the expansion of word is assigned to parame­
ter. The value of parameter is then substituted.
Positional parameters and special parameters may
not be assigned to in this way.

For just 5 variables I would do :

: ${V1:=test}
: ${V2:=test}
: ${V3:=test}
: ${V4:=test}
: ${V5:=test}

But back to our yesterday code :

for i in ${array[*]}; do eval "[red]: \${[/red]V$i[red]:[/red]=test[red]}[/red]"; done

Feherke.

http://rootshell.be/~feherke/