Using a variable to refer to another variable in Bash

Question

x=1 c1=string1 c2=string2 c3=string3  echo $c1 string1 

I'd like to have the output be string1 by using something like: echo $(c($x))

So later in the script I can increment the value of x and have it output string1, then string2 and string3.

Can anyone point me in the right direction?

Answer 1

See the Bash FAQ: How can I use variable variables (indirect variables, pointers, references) or associative arrays?

To quote their example:

realvariable=contents ref=realvariable echo "${!ref}"   # prints the contents of the real variable 

To show how this is useful for your example:

get_c() { local tmp; tmp="c$x"; printf %s "${!tmp}"; } x=1 c1=string1 c2=string2 c3=string3 echo "$(get_c)" 

If, of course, you want to do it the Right Way and just use an array:

c=( "string1" "string2" "string3" ) x=1 echo "${c[$x]}" 

Note that these arrays are zero-indexed, so with x=1 it prints string2; if you want string1, you'll need x=0.

Answer 2

Try this:

eval echo \$c$x 

Like others said, it makes more sense to use array in this case.