There are two options for viewing the query caching on a server:

When logged into mysql you can use the following command to view query cache size (note: 0 means that no caching has been enabled)

SHOW VARIABLES LIKE 'query_cache_size'; 

If you have configured your .my.cnf file then you are able to perform the following command from your shell without needing to enter into mysql:

mysql -e 'show variables;' | grep query_cache_size

Output should look similar to:

mysql> SHOW VARIABLES LIKE 'query_cache_size';
+------------------+-------+
| Variable_name    | Value |
+------------------+-------+
| query_cache_size | 0     |
+------------------+-------+

query_cache_size – This is the size of the cache in bytes. Setting this value to 0 will effectively disable caching.
query_cache_type – This value must be ON or 1 for query caching to be enabled by default.
query_cache_limit – This is the maximum size query (in bytes) that will be cached.

An example of editing the /etc/my.cnf file is:

query_cache_size = 268435456
query_cache_type=1
query_cache_limit=1048576

The command below is an example of setting the global caching of mysql to 16MB.

SET GLOBAL query_cache_size = 16777216;