In Shell script how can i loop through a variable containing other variables

Using bash

With bash, we can use arrays and indirection:

parentClients=(name1 name2) effectedClients=(value1 value2) otherClients=(something1 something2 something3) client_types=(parentClients effectedClients otherClients) for client in "${client_types[@]}" do echo "client=$client" c=$client[@] for ct in "${!c}" do echo " ct=$ct" done echo "done with one set" done 

This produces the output:

client=parentClients ct=name1 ct=name2 done with one set client=effectedClients ct=value1 ct=value2 done with one set client=otherClients ct=something1 ct=something2 ct=something3 done with one set 

The statement parentClients=(name1 name2) creates an array named parentClients with values name1 and name2. The expression ${!c} uses indirection to access the array whose name is given by c.

Using POSIX shell

With a POSIX shell, we must use variables instead of arrays and, in place of indirection, we use eval:

parentClients="name1 name2" effectedClients="value1 value2" otherClients="something1 something2 something3" client_types="parentClients effectedClients otherClients" for client in $client_types do echo "client=$client" eval "client_list=\$$client" # Potentially dangerous step for ct in $client_list do echo " ct=$ct" done echo "done with one set" done 

Because eval requires some trust in the source of the data, it should be used with caution.

This produces the output:

client=parentClients ct=name1 ct=name2 done with one set client=effectedClients ct=value1 ct=value2 done with one set client=otherClients ct=something1 ct=something2 ct=something3 done with one set