content/commands/eval_ro.md
This is a read-only variant of the [EVAL]({{< relref "/commands/eval" >}}) command that cannot execute commands that modify data.
For more information about when to use this command vs [EVAL]({{< relref "/commands/eval" >}}), please refer to [Read-only scripts]({{< relref "develop/programmability#read-only-scripts" >}}).
For more information about [EVAL]({{< relref "/commands/eval" >}}) scripts please refer to [Introduction to Eval Scripts]({{< relref "/develop/programmability/eval-intro" >}}).
> SET mykey "Hello"
OK
> EVAL_RO "return redis.call('GET', KEYS[1])" 1 mykey
"Hello"
> EVAL_RO "return redis.call('DEL', KEYS[1])" 1 mykey
(error) ERR Error running script (call to b0d697da25b13e49157b2c214a4033546aba2104): @user_script:1: @user_script: 1: Write commands are not allowed from read-only scripts.
| Redis Software | Redis Cloud | <span style="min-width: 9em; display: table-cell">Notes</span> | |:----------------------|:-----------------|:------| | <span title="Supported">✅ Standard</span> <span title="Supported"><nobr>✅ Active-Active</nobr></span> | <span title="Supported">✅ Standard</span> <span title="Supported"><nobr>✅ Active-Active</nobr></span> | |
{{< multitabs id="eval-ro-return-info" tab1="RESP2" tab2="RESP3" >}}
The return value depends on the script that was executed.
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The return value depends on the script that was executed.
{{< /multitabs >}}