topic Re: ${X_${Y}} in Operating System - HP-UX

${X_${Y}}

Praveen Bezawada — Sun, 29 Jul 2001 12:53:50 GMT

Hi
In shell can we do something of the kind

${X_${Y}} to print the value of X_2 when $Y=2

Re: ${X_${Y}}

James R. Ferguson — Sun, 29 Jul 2001 13:54:27 GMT

Hi Praveen:

While this seems intuitive. I don't think this will work. From the 'sh-posix' man pages in the parameter substitution discussion you can note: "The shell reads all the characters from ${ to the matching } as part of the same word, even if it contains braces or metacharacters."

Regards!

...JRF...

Re: ${X_${Y}}

Satish Y — Sun, 29 Jul 2001 14:43:25 GMT

No, it is not possible.

Cheers...
Satish.

Re: ${X_${Y}}

James R. Ferguson — Sun, 29 Jul 2001 14:55:43 GMT

Hi Praveen:

Another comment: You could consider setting and referencing your variables in an array.

...JRF...

Re: ${X_${Y}}

A. Clay Stephenson — Sun, 29 Jul 2001 19:18:09 GMT

Hi Praveen:

One other option you have is to set up associative arrays in awk so that your values are no referenced by numerical values but rather by strings such as "X1","X2","red","Blue".

Regards, Clay

Re: ${X_${Y}}

Frank Li — Mon, 30 Jul 2001 00:48:58 GMT

Why not use $X_$Y or $X_${Y} directly ?

The shell will try its best to explain the variable !

Re: ${X_${Y}}

Curtis Larson — Mon, 30 Jul 2001 01:54:59 GMT

what you need to use is "eval"

eval print \"\$X_$Y\"

sometimes it is easier not to mess with the quotes and do something like

eval z=\$X_$Y
print $z

Re: ${X_${Y}}

Magdi KAMAL — Mon, 30 Jul 2001 05:26:39 GMT

Hi Praveen,

Try the following , it works :

echo ${X}_${Y}

Magdi

Re: ${X_${Y}}

Carlos Fernandez Riera — Mon, 30 Jul 2001 10:46:23 GMT

Arrays in shell:

set -A x

x[1]=jjjjjj
x[2]=yyyyyy

y=2

echo ${x[$y]}