CFLib.org – Common Function Library Project

Description:
Convert any number between the following units of memory: bit, byte, kilobit, kilobyte, megabit, megabyte, gigabit, gigabyte, terabit, terabyte, petabit, petabyte, exabit, exabyte, zettabit, zettabyte, yottabit, and yottabyte. Can also specify number format to return.

Return Values:
returns a string

Example:

<cfset kb = convertMemoryUnit(1024,"byte","kilobyte") />

Parameters:

Full UDF Source:

<!---
 Converts a unit of memory to another unit of memory.
 
 @param num      number to convert (Required)
 @param fromUnit      unit to convert from (Required)
 @param toUnit      unit to convert to (Required)
 @param format      format to return number in (Optional)
 @return returns a string 
 @author Chris Schofield (chris@chrisschofield.com) 
 @version 0, May 9, 2009 
--->
<cffunction name="convertMemoryUnit" access="public" returntype="string">
    <!--- Number to convert. CMS --->
    <cfargument name="num"         required="true" type="numeric" />
    <!--- Memory unit of arguments.num (byte, kilobyte, etc.). CMS --->
    <cfargument name="fromunit"    required="true" type="string" />
    <!--- Memory to convert to. CMS --->
    <cfargument name="tounit"     required="true" type="string" />
    <!--- Number format to return (9.99, 9.99999, etc.). CMS --->
    <cfargument name="format"     default="9.9"    type="string" />

    <!--- Convert the number to bytes. CMS --->
    <cfset var bytes = 0 />
    <cfset var conv = 0 />

    <!--- Then convert to the specified unit. CMS --->
    <cfswitch expression="#arguments.fromunit#">
        <cfcase value="bit">             <cfset bytes = (arguments.num/8) />         </cfcase>
        <cfcase value="byte">             <cfset bytes = arguments.num />             </cfcase>
        <cfcase value="kilobit">         <cfset bytes = (arguments.num*(2^10)/8) />    </cfcase>
        <cfcase value="kilobyte">         <cfset bytes = (arguments.num*(2^10)) />    </cfcase>
        <cfcase value="megabit">         <cfset bytes = (arguments.num*(2^20)/8) />    </cfcase>
        <cfcase value="megabyte">         <cfset bytes = (arguments.num*(2^20)) />    </cfcase>
        <cfcase value="gigabit">         <cfset bytes = (arguments.num*(2^30)/8) />    </cfcase>
        <cfcase value="gigabyte">         <cfset bytes = (arguments.num*(2^30)) />    </cfcase>
        <cfcase value="terabit">         <cfset bytes = (arguments.num*(2^40)/8) />    </cfcase>
        <cfcase value="terabyte">         <cfset bytes = (arguments.num*(2^40)) />    </cfcase>
        <cfcase value="petabit">         <cfset bytes = (arguments.num*(2^50)/8) />    </cfcase>
        <cfcase value="petabyte">         <cfset bytes = (arguments.num*(2^50)) />    </cfcase>
        <cfcase value="exabit">         <cfset bytes = (arguments.num*(2^60)/8) />    </cfcase>
        <cfcase value="exabyte">         <cfset bytes = (arguments.num*(2^60)) />    </cfcase>
        <cfcase value="zettabit">         <cfset bytes = (arguments.num*(2^70)/8) />    </cfcase>
        <cfcase value="zettabyte">         <cfset bytes = (arguments.num*(2^70)) />    </cfcase>
        <cfcase value="yottabit">         <cfset bytes = (arguments.num*(2^80)/8) />    </cfcase>
        <cfcase value="yottabyte">         <cfset bytes = (arguments.num*(2^80)) />    </cfcase>
        <cfdefaultcase>
            <cfthrow message="Could not convert #arguments.num# to #arguments.fromunit#."
                    detail="Unit #arguments.fromunit# is not supported." />
        </cfdefaultcase>
    </cfswitch>

    <!--- First convert to bytes. CMS --->
    <cfswitch expression="#arguments.tounit#">
        <cfcase value="bit">         <cfset conv = (bytes*8) />             </cfcase>
        <cfcase value="byte">         <cfset conv = bytes />                 </cfcase>
        <cfcase value="kilobit">     <cfset conv = (bytes/(2^10)*8) />    </cfcase>
        <cfcase value="kilobyte">     <cfset conv = (bytes/(2^10)) />        </cfcase>
        <cfcase value="megabit">     <cfset conv = (bytes/(2^20)*8) />    </cfcase>
        <cfcase value="megabyte">     <cfset conv = (bytes/(2^20)) />        </cfcase>
        <cfcase value="gigabit">     <cfset conv = (bytes/(2^30)*8) />    </cfcase>
        <cfcase value="gigabyte">     <cfset conv = (bytes/(2^30)) />        </cfcase>
        <cfcase value="terabit">     <cfset conv = (bytes/(2^40)*8) />    </cfcase>
        <cfcase value="terabyte">     <cfset conv = (bytes/(2^40)) />        </cfcase>
        <cfcase value="petabit">     <cfset conv = (bytes/(2^50)*8) />    </cfcase>
        <cfcase value="petabyte">     <cfset conv = (bytes/(2^50)) />        </cfcase>
        <cfcase value="exabit">     <cfset conv = (bytes/(2^60)*8) />    </cfcase>
        <cfcase value="exabyte">     <cfset conv = (bytes/(2^60)) />        </cfcase>
        <cfcase value="zettabit">     <cfset conv = (bytes/(2^70)*8) />    </cfcase>
        <cfcase value="zettabyte">     <cfset conv = (bytes/(2^70)) />        </cfcase>
        <cfcase value="yottabit">     <cfset conv = (bytes/(2^80)*8) />    </cfcase>
        <cfcase value="yottabyte">     <cfset conv = (bytes/(2^80)) />        </cfcase>
        <cfdefaultcase>
            <cfthrow message="Could not convert #arguments.num# to #arguments.tounit#."
                    detail="Unit #arguments.tounit# is not supported." />
        </cfdefaultcase>
    </cfswitch>

    <!--- Then convert the bytes to the tounit. CMS --->
    <cfreturn NumberFormat(conv,arguments.format) />
</cffunction>