I need to read binary fields from Postgres. I store them in Postgres in BYTEA type fields.
Postgres returns BYTEA fields in format where "bad" characters are replaced with octal codes in format \ooo

I created the following routine to convert abytea type to binary format.
Unfortunately, my fields sizes can be up to 2 MB.
I this case the following conversion takes more than 10 secods.

How to speed up binary data retrieval ?

cres=ByteA2Str( replicate( 'a\000', 10**7) )

FUNCTION ByteA2Str( cStr )
LOCAL cTempFN
cTempFN = SYS(2015)+'.bin'
Bytea2File( m.cStr, m.cTempFN )
LOCAL cRes
cRes= FILETOSTR(m.cTempFN)
DELETE FILE (m.cTempFN)
RETURN m.cres

PROCEDURE BYTEA2File( cBytea, cFN )
LOCAL cInpFn, inp, x, cchar, cchar1, cchar2, cchar3
cInpFn= SYS(2015)+'.txt'
STRTOFILE( m.cBytea, m.cInpFn)
inp = FOPEN(m.cInpFn,0)
nlen=LEN(m.cByteA)
x = FCREATE(m.cFN)
DO WHILE !FEOF(m.inp)
  cchar = FREAD(m.inp,1)
  IF m.cchar#'\'
	FWRITE(m.x, m.cchar )
	LOOP
	ENDIF
	
  cchar1 = FREAD(m.inp,1)
  IF m.cchar1='\'
	FWRITE(m.x, m.cchar1 )
	LOOP
	ENDIF

  cchar2 = FREAD(m.inp,1)
  cchar3 = FREAD(m.inp,1)

  IF !BETWEEN(m.cchar1, '0','7') OR ;
     !BETWEEN(m.cchar2, '0','7') OR !BETWEEN(m.cchar3, '0','7')
    ERROR 'Non-octal digit after \ '+ m.cFn
    ENDIF

  FWRITE(m.x, CHR( VAL(m.cchar1)*64 + ;
                     VAL(m.cchar2)*8 + ;
                     VAL(m.cchar3) ) )
  ENDDO

FCLOSE(m.x)
FCLOSE(m.inp)
DELETE FILE (m.cInpFn)
ENDPROC