M428: Search for Byte-Content

Author(s): J. Zoll Library: KERNLIB
Submitter: Submitted: 01.06.1973
Language: Fortran or Assembler Revised: 15.09.1978

LOCBYT searches through a vector in steps of 1 or more words looking for the first word which has a certain bit configuration in a certain part of the word.

Structure:

FUNCTION subprogram
User Entry Names: LOCBYT

Usage:

    J = LOCBYT(IT,VECT,N,INC,L,NBITS)
searches through the N element vector VECT, but only looking every INC words for the first word which contains IT in the byte (L,NBITS), and returns its address in J which may be 1, INC+1, 2*INC+1, 3*INC+1, etc.

IT must contain the desired byte value right-justified with zero-fill.

tex2html_wrap_inline67 is returned if such a word is not found, or if tex2html_wrap_inline69 .

The byte (L,NBITS) is a byte of NBITS bits, occupying the bits L,L+1,...,L+NBITS-1. The bits are numbered as with the routines of BITBYT (M421) / PACBYT (M422): tex2html_wrap_inline71 ; bit 1 is the least significant bit of the word.
tex2html_wrap_inline73


Michel Goossens Wed Jun 5 07:18:56 METDST 1996