SetAtLike()

SetAtLike()

Determine scan behaviour in some string functions

Syntax

      SetAtLike ([<nMode>] [, <[@]cWildcard>]) --> nOldMode

Arguments

[<nMode>] :

       CT_SetAtLike_EXACT -> characters are compared exactly

       CT_SetAtLike_WILDCARD -> characters are compared using a wildcard character

       The default value is CT_SetAtLike_EXACT.

[<[@]cWildcard>] determines the character that is subsequently used as a wildcard character for substring scanning. The default value is “?”.

NEW: If this parameter is passed by reference [@], the current wildcard character is stored in <cWildcard>.

Returns

nOldMode old (if nMode is a numeric value) or current state of the switch

Description

In the following CT3 functions, strings are compared on a character base:

ATADJUST(), ATNUM(), AFTERATNUM(), BEFOREATNUM(), ATREPL(), NUMAT(), STRDIFF()

With the SetAtLike function, one can determine when characters are considered to match within these functions. If CT_SetAtLike_WILDCARD is set (e.g. “?”), then “?” matches every other character.

<nMode> can be one of the following values that are defined in ct.ch

 
      Definition            | Value 
      ----------------------|------ 
      CT_SetAtLike_EXACT    |   0 
      CT_SetAtLike_WILDCARD |   1

Compliance

This function is fully CT3 compatible, but allows to pass the second parameter by reference so that the current wildcard character can be determined.

Platforms

All

Files

Source is ctstr.c, header is ct.ch, library is ct3.

CT_ATADJUST

 ATADJUST()
 Adjusts the beginning position of a sequence within a string
------------------------------------------------------------------------------
 Syntax

     ATADJUST(<cSearchFor>,<cString>,<nEndpoint>,
        [<nCounter>],[<nIgnore>],[<nCharacter|
        <cCharacter>]) --> cString

 Arguments

     <cSearchFor>  Designates the character string for which the function
     searches, or the character string that provides the reference point for
     adjustment.

     <cString>  Designates the character string within which the
     adjustment occurs.

     <nTargetPosition>  Designates from which position within the
     character string the search expression is adjusted.

     <nCounter>  Designates which occurrence of the <Searchexpression> is
     taken into account.  The default value is for the last occurrence.

     <nIgnore>  Designates the number of characters at the beginning of
     the search string that are removed.  The default value is none.

     <nCharacter|cCharacter>  Designates a character, as necessary, to
     carry out the adjustment.  It can be an individual character or an ASCII
     value between 0 and 255.  The default value is a space CHR(32).

 Returns

     ATADJUST() returns the modified character string.

 Description

     The function first looks for the <cSearchFor> parameter within the
     character string.  From this point, the rest of the <cString> is moved
     (adjusted) by either inserting or removing blanks until the
     <nTargetPosition> is reached.  In lieu of blanks, <nCharacter>|
     <cCharacter> can be used as a fill character.

     Additionally you can specify that the nth occurrence of <cSearchFor> be
     used and whether or not a specific number of characters at the beginning
     of the search string is eliminated.

 Note

     .  Using CSETATMUPA() can influence how the search is performed.
        Using SETATLIKE() permits the use of wild cards within the search
        sequence.

 Examples

     .  Align comments at column 60.  The search is for the first
        occurrence of "//".  Since there is usually at least one space before
        each "//", search for " //":

        ? ATADJUST(" //", Line, 60, 1)

     .  Move the extensions for the following list of file names to
        position 10 and eliminate the ".":

        WINDOW.DBF
        PLZ.DBF
        BACK.DBF
        HELP.DBF
        LOG.DBF

        CHARREM(".", ATADJUST(".", File, 10))

        WINDOW      DBF

        PLZ         DBF
        BACK        DBF
        HELP        DBF
        LOG         DBF

     .  Use ATADJUST() with CSETATMUPA().  There is always a problem
        determining whether "AA" occurs twice or three times in "AAA".
        Depending on CSETATMUPA(), the function searches behind the last
        character, or starts from the last character of a located sequence:

        CSETATMUPA(.F.)
        ? ATADJUST("AA", "123AAABBB", 7, 2)       // Sequence not found

        CSETATMUPA(.T.)
        ? ATADJUST("AA", "123AAABBB", 7, 2)       // "123A  AABBB"

See Also: SETATLIKE() CSETATMUPA()

Tools – String Manipulations

Introduction 
ADDASCII()   Adds a value to each ASCII code in a string
AFTERATNUM() Returns remainder of a string after nth appearance of sequence
ASCIISUM()   Finds sum of the ASCII values of all the characters of a string
ASCPOS()     Determines ASCII value of a character at a position in a string
ATADJUST()   Adjusts the beginning position of a sequence within a string
ATNUM()      Determines the starting position of a sequence within a string
ATREPL()     Searches for a sequence within a string and replaces it
ATTOKEN()    Finds the position of a token within a string
BEFORATNUM() Returns string segment before the nth occurrence of a sequence
CENTER()     Centers a string using pad characters
CHARADD()    Adds the corresponding ASCII codes of two strings
CHARAND()    Links corresponding ASCII codes of paired strings with AND
CHAREVEN()   Returns characters in the even positions of a string
CHARLIST()   Lists each character in a string
CHARMIRR()   Mirrors characters within a string
CHARMIX()    Mixes two strings together
CHARNOLIST() Lists the characters that do not appear in a string
CHARNOT()    Complements each character in a string
CHARODD()    Returns characters in the odd positions of a string
CHARONE()    Reduces adjoining duplicate characters in string to 1 character
CHARONLY()   Determines the common denominator between two strings
CHAROR()     Joins the corresponding ASCII code of paired strings with OR
CHARPACK()   Compresses (packs) a string
CHARRELA()   Correlates the character positions in paired strings
CHARRELREP() Replaces characters in a string depending on their correlation
CHARREM()    Removes particular characters from a string
CHARREPL()   Replaces certain characters with others
CHARSORT()   Sorts sequences within a string
CHARSPREAD() Expands a string at the tokens
CHARSWAP()   Exchanges all adjoining characters in a string
CHARUNPACK() Decompresses (unpacks) a string
CHARXOR()    Joins ASCII codes of paired strings with exclusive OR operation
CHECKSUM()   Calculates the checksum for a character string (algorithm)
COUNTLEFT()  Counts a particular character at the beginning of a string
COUNTRIGHT() Counts a particular character at the end of a string
CRYPT()      Encrypts and decrypts a string
CSETATMUPA() Determines setting of the multi-pass mode for ATXXX() functions
CSETREF()    Determines whether reference sensitive functions return a value
EXPAND()     Expands a string by inserting characters
JUSTLEFT()   Moves characters from the beginning to the end of a string
JUSTRIGHT()  Moves characters from the end of a string to the beginning
LIKE()       Compares character strings using wildcard characters
LTOC()       Converts a logical value into a character
MAXLINE()    Finds the longest line within a string
NUMAT()      Counts the number of occurrences of a sequence within a string
NUMLINE()    Determines the number of lines required for string output
NUMTOKEN()   Determines the number of tokens in a string
PADLEFT()    Pads a string on the left to a particular length
PADRIGHT()   Pads a string on the right to a particular length
POSALPHA()   Determines position of first alphabetic character in a string
POSCHAR()    Replaces individual character at particular position in string
POSDEL()     Deletes characters at a particular position in a string
POSDIFF()    Finds the first position from which two strings differ
POSEQUAL()   Finds the first position at which two strings are the same
POSINS()     Inserts characters at a particular position within a string
POSLOWER()   Finds the position of the first lower case alphabetic character
POSRANGE()   Determines position of first character in an ASCII code range
POSREPL()    Replaces one or more characters from a certain position
POSUPPER()   Finds the position of the first uppercase, alphabetic character
RANGEREM()   Deletes characters that are within a specified ASCII code range
RANGEREPL()  Replaces characters within a specified ASCII code range
REMALL()     Removes characters from the beginning and end of a string
REMLEFT()    Removes particular characters from the beginning of a string
REMRIGHT()   Removes particular characters at the end of a string
REPLALL()    Exchanges characters at the beginning and end of a string
REPLLEFT()   Exchanges particular characters at the beginning of a string
REPLRIGHT()  Exchanges particular characters at the end of a string
RESTTOKEN()  Recreates an incremental tokenizer environment
SAVETOKEN()  Saves the incremental tokenizer environment to a variable
SETATLIKE()  Provides an additional search mode for all AT functions
STRDIFF()    Finds similarity between two strings (Levenshtein Distance)
STRSWAP()    Interchanges two strings
TABEXPAND()  Converts tabs to spaces
TABPACK()    Converts spaces in tabs
TOKEN()      Selects the nth token from a string
TOKENAT()    Determines the most recent TOKENNEXT() position within a string
TOKENEND()   Determines if more tokens are available in TOKENNEXT()
TOKENINIT()  Initializes a string for TOKENNEXT()
TOKENLOWER() Converts initial alphabetic character of a token into lowercase
TOKENNEXT()  Provides an incremental tokenizer
TOKENSEP()   Provides separator before/after most recently retrieved TOKEN()
TOKENUPPER() Converts the initial letter of a token into upper case
VALPOS()     Determines numerical value of character at particular position
WORDONE()    Reduces multiple appearances of double characters to one
WORDONLY()   Finds common denominator of 2 strings on double character basis
WORDREPL()   Replaces particular double characters with others
WORDSWAP()   Exchanges double characters lying beside each other in a string
WORDTOCHAR() Exchanges double characters for individual ones