scripting question

[yap]

Hi,
How can I put argument as variable in script? Such as:

If first argument to a script is "Arg1". If I do

x=1
echo $($x)

Can I get "Arg1" to print out? I know this is not the correct way to do. Anyone can point out the right way? Thanks.

regards,
tenghin

[Bernhard Mueller]

Hi,

x=$1
echo $($x)

Regards,
Bernhard

[Umapathy S]

The arguments are passed as $n where n is 1, 2, 3...

You can capture them as $1, $2 etc. You can use them as any other variable.

echo $1

HTH,
Umapathy

[yap]

Hi Bernhard,
Thanks for the reply. The reason I want to make the argument as variable is because sometime the position of argument can change, may be first argument, may be second. So I don't think your suggestion can work. Do you have other suggestion ?

regards,
tenghin

[marc seguin · Accepted solution]

If your command is as "./myscript arg1", then you can get the value arg1 inside your script using $1 ($2, $3, ... for 2nd, 3rd,... parameters).

echo $1
=> arg1

If $arg1 is a parameter ($arg1=value1), then you can do :
eval echo \${$1}
=> value1

marc.

[Umapathy S]

Tenghin,
At some point you have to identify what that incoming argument means. At that same point you can assign them to your variable of choice.

I dont find any problem here.

HTH,
Umapathy

[yap]

Hi Marc,
Thanks a lot. That is just what I want.

Umapathy,
Thanks for you reply also.


Thanks guys!!

regards,
tenghin

[Bernhard Mueller]

Hi Thenghin,

so I guess you want something like

./script -1 arg1 -2 arg2
would work exactly like
./script -2 arg2 -1 arg1

???

then you would use a case statement and use shift for each $1 to read each script argument sequentially and set variables according to whether -1 -2 etc have been found until you have gone through the whole command line.

Regards,
Bernhard

[yap]

Hi Bernhard,
Actually what I want is assign the second last argument to a variable, such as :

x=$#
y=`expr $x - 1`
h=`eval echo \${$y}`
echo $h


I can do "eval echo \${$y}" alone but cannot assign to variable h as above.Any idea anyone ?

regards,
tenghin

[Umapathy S]

Tenghin,
One way to do is to use the shift. Go on shifting till last but one.

HTH,
Umapathy