Command: STR.LENGTH

Overview

The STR.LENGTH command is used to retrieve the length (in characters) of a string value stored at a specified key in the Fleare key-value store. If the key does not exist, it returns 0. It validates the key and ensures the value is of string type.

Command Name

STR.LENGTH

Description

This command returns the number of characters in the string value stored at the given key.

  • If the key does not exist, it returns 0 .

  • If the key exists but is associated with a non-string value, an error is returned.

  • This command is read-only and does not modify any data.

Use Cases

Monitoring String Length

You can verify the size of messages, configurations, or serialized data before parsing.

Existence Check

Used to check if a key holds a value or not. If length 0 is returned, the key might not exist.

Validation Logic

Before processing, validate minimum or maximum required length of the value.

Syntax 

  STR.LENGTH <key>
  • <key> : The key for which the string length is to be retrieved.

Permissions

  • Read access required to the specified key.

  • No special or elevated privileges needed.

Input Examples

Key exists with a string value 
  localhost:9219> STR.SET greeting "Hello, Fleare"
Ok

localhost:9219> STR.LENGTH greeting
Ok 13
Key does not exist 
  localhost:9219> STR.LENGTH unknown_key
Ok 0
Value is not a string 
  localhost:9219> LIST.RPUSH mylist "one"
Ok

localhost:9219> STR.LENGTH mylist
ERR: invalid value: the existing value for the provided key must be a string

Output Examples

Case Output
Valid string key Ok <length>
Non-existing key Ok 0
Value is not string type ERR: ...

Behavior on Error

Condition Error Message
No key provided ERR: invalid key: Key must be provided
Too many/few arguments ERR: invalid arguments: invalid number of arguments
Key format is invalid ERR: invalid key: <validation error>
Value is not of string type ERR: invalid value: the existing value for the provided key must be a string