Par2: Useful API Functions 1998-07-27 -- Frank Piscopo Prototypes of the following Clarion Runtime API Calls are declared in
CLIB.CLW - use the following embed:
Inside the Global Map
INCLUDE('CLIB.CLW')
For a complete list of all the documented calls, refer to Chapter 14 of the
Programmer's Guide.
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LOW-LEVEL FILE FUNCTIONS:
Access(*CSTRING,SHORT),SHORT
Usage: IF Access(p,a) ...
where p is the path to check, in a C-string,
and a is the access mode (use ff_: equates in EQUATES.CLW)
Purpose: Tests whether a file or directory can be accessed in
the specified mode (can be used for file existence tests).
API_Remove(*CSTRING),SHORT
Usage: IF API_Remove(p) ...
where p is pathname of the file to remove, in a C-string.
Purpose: Deletes a file (not a directory; for this, refer to RmDir below).
API_Rename(*CSTRING,*CSTRING),SHORT
Usage: IF API_Rename(p1,p2) ...
where p1 is the original filename in a C-string,
and p2 is the new filename in a C-string.
Purpose: Renames a file or directory.
FnSplit(*CSTRING,*CSTRING,*CSTRING,*CSTRING,*CSTRING),SHORT
Usage: IF FnSplit(p,v,d,n,e) ...
where p is a pathname to split, in a C-string,
v is a C-string to receive the DRIVE letter,
d is a C-string to receive the DIRECTORY,
n is a C-string to receive the FILENAME,
e is a C-string to receive the EXTENSION.
Purpose: Splits a pathname into the various parts as listed above.
I should assume that unspecified parts in p are
taken from the current default directory and drive.
MkDir(*CSTRING),SHORT
Usage: IF MkDir(d) ...
where d is the directory pathname, in a C-string.
Purpose: Creates a new directory, specified by d.
RmDir(*CSTRING),SHORT
Usage: IF RmDir(d) ...
where d is the directory pathname, in a C-string.
Purpose: Deletes a directory, which presumably should be empty.
--- All the above functions return a SHORT to indicate success or failure of the
function.
STRING FUNCTIONS:
IsAscii(SHORT),SHORT
Usage: IF IsAscii(VAL(c)) ...
where c is any one-character constant or string variable.
Purpose: Tests whether c is an ASCII character.
IsCntrl(SHORT),SHORT
Usage: IF IsCntrl(VAL(c)) ...
where c is any one-character constant or string variable.
Purpose: Tests whether c is a control character.
IsDigit(SHORT),SHORT
Usage: IF IsDigit(VAL(c)) ...
where c is any one-character constant or string variable.
Purpose: Tests whether c is a numeric digit character.
IsGraph(SHORT),SHORT
Usage: IF IsGraph(VAL(c)) ...
where c is any one-character constant or string variable.
Purpose: Tests whether c is a printable character, excluding SPACE.
IsPrint(SHORT),SHORT
Usage: IF IsPrint(VAL(c)) ...
where c is any one-character constant or string variable.
Purpose: Tests whether c is a printable character, including SPACE.
IsPunct(SHORT),SHORT
Usage: IF IsPunct(VAL(c)) ...
where c is any one-character constant or string variable.
Purpose: Tests whether c is a punctuation character.
IsSpace(SHORT),SHORT
Usage: IF IsSpace(VAL(c)) ...
where c is any one-character constant or string variable.
Purpose: Tests whether c is a white-space character (space, tab, CR, LF, FF).
IsXDigit(SHORT),SHORT
Usage: IF IsXDigit(VAL(c)) ...
where c is any one-character constant or string variable.
Purpose: Tests whether c is a hex digit (like IsDigit() plus A,B,C,D,E,F).
StrCSpn(*CSTRING,*CSTRING),USHORT
Usage: IF StrCSpn(c1,c2) ...
where c1 and c2 are C-string variables.
Purpose: Finds the first occurance in c2 of any character in c1
(don't take my word for this one; the meaning of c1 and c2 may be swapped).
StrSpn(*CSTRING,*CSTRING),USHORT
Usage: IF StrCSpn(c1,c2) ...
where c1 and c2 are C-string variables.
Purpose: Finds the first character in c2 which IS NOT in c1
(ditto, meaning of c1 and c2 may be swapped).
StrRev(*CSTRING),CSTRING
Usage: c1 = StrRev(c2)
where c1 and c2 are C-string variables.
Purpose: Returns the reverse of a string
(StrRev('Reverse') returns 'esreveR')
--- Most of the above functions can be used in user-written functions
to make them more useful to test whole strings. For example,
one could write something like the following to test whether a
string is free of non-printable characters:
!----------------------------------------------
IsPrintS PROCEDURE(s)
l LONG,AUTO
i LONG,AUTO
CODE
l = LEN(CLIP(s))
LOOP i = 1 TO l
IF ~IsPrint(VAL(s[i])) THEN RETURN FALSE.
END
RETURN TRUE
!----------------------------------------------
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