FindAndSplit

The function splits a string into two strings.

The character string is searched for a separator (e.g. "\") from left to right. The strings on both sides of this first occurrence of the separator are output.

The search direction can be changed with the parameter bSearchFromRight so that the string is searched from right to left.

The function stops the checking of the input length after Parameterlist.cMaxCharacters characters in order to avoid an infinite loop.

FUNCTION FindAndSplit : BOOL

The return value is TRUE if the separator was found and the division and output of the strings was successful.

VAR_INPUT
    pSeparator        : POINTER TO STRING;
    pSrcString        : POINTER TO STRING;
    pLeftString       : POINTER TO STRING;
    nLeftSize         : UDINT;
    pRightString      : POINTER TO STRING;
    nRightSize        : UDINT;
    bSearchFromRight  : BOOL;
END_VAR

Sample "Splitting into several substrings":

This sample shows how to split a string ''machines/machine1/module2/data/tx' into several strings ['machines', 'machine1', 'module2', 'data', 'tx']. To this end the function FindAndSplit() is called repeatedly in a loop.

PROGRAM MAIN
VAR
    sSrc         : STRING(255) := 'machines/machine1/module2/data/tx';
    sSeparator   : STRING(1) := '/';
    aSplit       : ARRAY[1..cMax] OF STRING(255);
    bResultSplit : BOOL;
    i            : UDINT;
END_VAR
VAR CONSTANT
    cMax         : UDINT := 9;
END_VAR

aSplit[1] := sSrc;
FOR i:=1 TO cMax-1 DO
    bResultSplit := FindAndSplit( pSeparator     := ADR(sSeparator),  pSrcString := ADR(aSplit[i]), 
                                  pLeftString    := ADR(aSplit[i]),   nLeftSize  := SIZEOF(aSplit[i]), 
                                  pRightString   := ADR(aSplit[i+1]), nRightSize := SIZEOF(aSplit[i+1]),
                                  bSearchFromRight := FALSE );
    IF NOT bResultSplit THEN
        EXIT;
    END_IF
END_FOR

Sample "Merging several strings":

This sample shows how to combine several strings ['machines', 'machine1', 'module2', 'data', 'tx'] into one string 'machines/machine1/module2/data/tx'.

PROGRAM MAIN
VAR
    sSeparator    : STRING(1) := '/';
    aSplit        : ARRAY[1..cMax] OF STRING(255) := ['machines', 'machine1', 'module2', 'data', 'tx'];
    sJoined       : STRING(255);
    bResultConcat : BOOL;
    i             : UDINT;
END_VAR
VAR CONSTANT
    cMax          : UDINT := 5;
END_VAR

sJoined := aSplit[1];
FOR i:=1 TO cMax-1 DO
    bResultConcat := CONCAT2(pSrcString1 := ADR(sJoined), pSrcString2 := ADR(sSeparator), pDstString := ADR(sJoined), nDstSize := SIZEOF(sJoined));
    IF NOT bResultConcat THEN
        EXIT;
    END_IF
    bResultConcat := CONCAT2(pSrcString1 := ADR(sJoined), pSrcString2 := ADR(aSplit[i+1]), pDstString := ADR(sJoined), nDstSize := SIZEOF(sJoined));
    IF NOT bResultConcat THEN
        EXIT;
    END_IF
END_FOR