I want to refer to a parameter in bash by using a number generated by a sum. How do I do this?
More specifically:
#!/bin/bash
$sum=${$1}
echo $sum
When I execute the script ./script.bash A B C D, if $sum = 3, then I want to开发者_Python百科 return C. How do I do this, does anyone know?
You can use the indirect expansion syntax:
${!parameter}
as described here.
(Also note that variable assignments should not have a $
on the left-hand side!)
Example:
$ cat script.bash
#!/bin/bash
sum=3
arg=${!sum}
echo $arg
$ ./script.bash A B C D
C
$
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