linux - Unbound variable during url printing in bash/shell -

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i have 2 variables want use derive 3rd variable:

export region_name=phx  export phx_url=https://www.google.com

i trying following:

echo "$((${region_name}_url))"

and following error:

-sh: https://www.google.com: syntax error in expression (error token "://www.google.com")

all trying derive environment variable other 1 not work simple that. think has escaped , not find online.

thanks in advance help.

$((...)) arithmetic expansion. didn't mean that. try normal variable expansion (with indirection) instead.

region_name=phx  phx_url=https://www.google.com  r_var=${region_name}_url      echo "${!r_var}"

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