Extracting hex numeric from strings?

[Conrad Hoffman]

I want to pull big-endian hex data out of a small wav file loaded into a string. The following works (needs to be expanded for more bytes), but just seems clumsy and indirect. Can anyone "pointer" me in a better direction?

 TEMP4H = HEX$(ASC(MID$(TempStr$, 26, 1)))     'high byte sample rate
 TEMP4L = HEX$(ASC(MID$(TempStr$, 25, 1)))     'low byte sample rate
 TEMP5 = VAL("&H" & TEMP4H & TEMP4L)

Thanks,
Conrad

[Bob Zale]

TEMP5& = CVL(TempStr$,25)
or
TEMP5??? = CVDWD(TempStr$, 25)

Best regards,

Bob Zale
PowerBASIC Inc.

[John Gleason]

You may also consider doing it as a WORD data type:

#COMPILE EXE
#DIM ALL

FUNCTION PBMAIN () AS LONG
    LOCAL TEMP4H,TEMP4L,tempStr AS STRING
    LOCAL temp5 AS WORD
    
    tempStr = "dfuitfguiti67y9o7yoigyiesdjuwj3we7373yuweshdehdehedeue"

    TEMP4H = HEX$(ASC(MID$(TempStr$, 26, 1)))     'high byte sample rate
    TEMP4L = HEX$(ASC(MID$(TempStr$, 25, 1)))     'low byte sample rate
    TEMP5 = VAL("&H" & TEMP4H & TEMP4L)
     ? STR$(TEMP5)
    TEMP5 = CVWRD(TempStr$, 25)
     ? STR$(TEMP5)
END FUNCTION

[Conrad Hoffman]

Thanks-much better! Sometimes I compare this forum to "pushing the easy button" in the office supply ads

[Pierre Bellisle]

One more word Conrad,

The next line is wrong,
TEMP4L = HEX$(ASC(MID$(TempStr, 25, 1)))

you need to have
TEMP4L = HEX$(ASC(MID$(TempStr, 25, 1)), 2)

becose, with the manipulation you do,
this byte in hex must be represented by 2 characters, (0x00 to 0xFF)
and you will need the leading zero if the byte value is under 0x10.
For example: 0x01 0x02 got to become 0x0102 and not 0x0012.

[Pierre Bellisle]

Also,
you may have a look at "DIM AT"
who can make life easier and faster in this case...

[font=courier new][size=2]
 [color=blue]LOCAL[/color] TempStr   [color=blue]AS STRING[/color]
 [color=blue]LOCAL[/color] WordCount [color=blue]AS LONG[/color]
 [color=blue]LOCAL[/color] Looper    [color=blue]AS LONG[/color] 
 
 WordCount = [color=blue]LEN[/color](TempStr) \ [color=red]2[/color]
 [color=blue]DIM[/color] wordArray([color=red]1[/color] [color=blue]TO[/color] WordCount) [color=blue]AS WORD AT STRPTR[/color](TempStr)
 [color=blue]FOR[/color] Looper = [color=red]1[/color] [color=blue]TO[/color] WordCount
   [color=blue]ROTATE LEFT[/color] wordArray(Looper), [color=red]8[/color] [color=green]'If conversion from Little Endian to Big Endian is needed.[/color]
   [color=blue]MSGBOX HEX$[/color](wordArray(Looper), [color=red]4[/color])
 [color=blue]NEXT[/color]
[/size][/font]

[Conrad Hoffman]

Thanks Pierre, I knew about the multiple bytes and just hadn't worried about it for the question. Didn't know about "DIM AT", so I'll look at that as well. It seems like my programming comes in bursts, and I tend to forget everything in between ;-(

[John Petty]

I think this is a perfect case for a Union

Union BtoLEnd
    b(1) as Byte
    i as Integer 
End Union

Function etc
Local Sp as Dword
local BE as BtoLend
    Dim TempByte(1 to Len(TempString$)) as Byte at StrPtr(TempString$)
    BE.b(1) = TempByte(25)
    BE.b(0) = TempByte(26)
    ' the little ended integer is now in BE.i