Unitech PT600, Programming Reference Manual

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CX = total matched times
DX:AX = pointer to current file position (not changed)
42 Search String in Formatted Data File Beginning at the Current
Position
Entry Parameter: AH = 42H
AL = 5 ; search forward (to the end of file)
6 ; search backward (to the beginning of
file)
BX = file handle
CH = n ; Total field number in the data record
CL = m ; search mth field
DS:DX = pointer to parameter block
Structure of parameter block for non-fixed length record data
file:
String length : 1 byte
String without ‘\0’ terminator : N bytes
0x00 1 byte
Field separator character : 1 byte
Structure of parameter block for fixed length record data file:
String length : 1 byte
String without ‘\0’ terminator : N bytes
Field #1 length: 1 byte
Field #2 length: 1 byte
. .
. .
. .
Field #n length: 1 byte
Return Value: 1) If string is found:
Carry flag = clear
DX:AX = pointer to current file position (at the beginning
of the
matched string)
2) If string is not found:
Carry flag = set
DX:AX = pointer to current file position (not changed)
42
Insert / Delete Data Block to / from File at the Current Position
Entry Parameter: AH = 42H
AL = 7 ; insert
8 ; delete