fromhex()

Converts a hexadecimal string to binary and returns it.

Syntax

Parameters

HEX_STR

A hexadecimal string or expression. Both uppercase and lowercase are accepted (0-9, a-f, A-F).

Description

The fromhex() function converts a hexadecimal string to binary (byte[]) and returns it. Returns null in the following cases:

• The argument is null
• The argument is not a string
• The string length is odd (cannot be split into bytes)
• The string contains non-hexadecimal characters

Passing a numeric constant or a negative number directly as an argument causes an error during the parsing phase.

Error codes

Usage examples

1. Converting a hexadecimal string to binary and decoding it as a string

   json "{'val': '68656c6c6f'}" | eval result = decode(fromhex(val))
   | # result: "hello"
   

2. Converting and verifying as hexadecimal again

   json "{'val': '68656c6c6f'}" | eval result = tohex(fromhex(val))
   | # result: "68656c6c6f"
   

3. Odd-length string input

   json "{'val': '616263646'}" | eval result = fromhex(val)
   | # result: null
   

4. NULL input

   json "{'val': null}" | eval result = fromhex(val)
   | # result: null
   

Compatibility

The fromhex() function has been available since before Sonar 4.0.