137 lines
3.1 KiB
Plaintext
137 lines
3.1 KiB
Plaintext
/*
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* File......: AT2.prg
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* Author....: Ralph Oliver, TRANSCOM SYSTEMS
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* CIS ID....: 74030,703
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*
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* This is an original work by Ralph Oliver and is placed in the
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* public domain.
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*
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* Modification history:
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* ---------------------
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*
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* Rev 1.2 15 Aug 1991 23:05:58 GLENN
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* Forest Belt proofread/edited/cleaned up doc
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*
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* Rev 1.1 12 Jun 1991 00:46:28 GLENN
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* Posted a referee suggestion: Around line 118, break out if no
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* occurrences (note the IF/ENDIF before the NEXT and RETURN at the
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* bottom of the function).
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*
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* Rev 1.0 07 Jun 1991 23:03:28 GLENN
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* Initial revision.
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*
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*
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*/
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/* $DOC$
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* $FUNCNAME$
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* FT_AT2()
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* $CATEGORY$
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* String
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* $ONELINER$
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* Find position of the nth occurrence of a substring
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* $SYNTAX$
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* FT_AT2( <cSearch>, <cTarget> [, <nOccurs> [, <lCaseSens> ] ] ) -> nPos
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* $ARGUMENTS$
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* <cSearch> is the character substring to search for.
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*
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* <cTarget> is the character string to search.
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*
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* <nOccurs> is the occurrence of cSearch to look for,
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* defaults to 1.
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*
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* <lCaseSens> is a logical value denoting case sensitivity.
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* If .F., then search is NOT sensitive to case,
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* defaults to .T.
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* $RETURNS$
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* The position of the nth occurrence of a substring
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* $DESCRIPTION$
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* This function will find the nth occurrence of a substring
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* within a string.
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* $EXAMPLES$
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* cSearch := "t"
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* cTarget := "This is the day that the Lord has made."
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*
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* FT_AT2( cSearch, cTarget ) // Returns ( 9 )
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*
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* FT_AT2( cSearch, cTarget, 2 ) // Returns ( 17 )
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*
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* FT_AT2( cSearch, cTarget, 2, .F. ) // Returns ( 9 )
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* $SEEALSO$
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* FT_FINDITH()
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* $END$
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*/
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#ifdef FT_TEST
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FUNCTION MAIN()
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LOCAL cSearch,cTarget,var0
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CLS
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? "TEST TO DEMONSTRATE EXAMPLES OF FT_AT2"
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?
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cSearch := 't'
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? "Find occurrences of 't' in: "
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cTarget := "This is the day that the Lord has made."
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?? cTarget
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?
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var0 := ft_at2( cSearch, cTarget )
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? PADR("FT_AT2( cSearch, cTarget ) -> ",40)
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?? var0
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?
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var0 := ft_at2( cSearch, cTarget, 2 )
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? PADR("FT_AT2( cSearch, cTarget, 2 ) -> ",40)
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??var0
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?
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var0 := ft_at2( cSearch, cTarget, 2, .F. )
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? PADR("FT_AT2( cSearch, cTarget, 2, .F. ) -> ",40)
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??var0
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?
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RETURN NIL
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#endif
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FUNCTION FT_AT2( cSearch, cTarget, nOccurs, lCaseSens )
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LOCAL nCount, nPos, nPos2 := 0
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LOCAL cSubstr := cTarget
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// Set default parameters as necessary.
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IF lCaseSens == NIL
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lCaseSens := .T.
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ENDIF
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IF nOccurs == NIL
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nOccurs := 1
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ENDIF
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FOR nCount := 1 TO nOccurs
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// Store position of next occurrence of cSearch.
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IF lCaseSens
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nPos := AT( cSearch, cSubstr )
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ELSE
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nPos := AT( UPPER( cSearch ), UPPER( cSubstr ) )
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ENDIF
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// Store position of cSearch relative to original string.
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nPos2 += nPos
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// Resize cSubstr
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cSubstr := SUBSTR( cSubstr, AT( cSearch, cSubstr ) +1 )
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// Breakout if there are no occurences here
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IF nPos == 0
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EXIT
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ENDIF
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NEXT
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RETURN ( nPos2 )
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