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File - Standard (EXAMPLE)
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(* example of how to use the CAA_FILE.library - file standard function blocks *)
PROGRAM FILE.STANDARD_PRG
VAR
xFileStdInit: BOOL:=FALSE;
uiFileStdState: UINT:=0;
sFileName: CAA.FILENAME:= 'TestFile.txt';
hFile: CAA.HANDLE;
sFileTestString: STRING:='Hello caa library user';
sFileString: STRING(100):='';
szFileSize1: CAA.SIZE := 0;
szFileSize2: CAA.SIZE := 0;
filop: FILE.Open;
filwr: FILE.Write;
filrd: FILE.Read;
filcl: FILE.Close;
filsp: FILE.SetPos;
END_VAR
IF NOT xFileStdInit THEN
filop(xExecute:=FALSE);
filcl(xExecute:=FALSE);
filwr(xExecute:=FALSE);
filrd(xExecute:=FALSE);
xFileStdInit:=TRUE;
uiFileStdState:=0;
ELSE
CASE uiFileStdState OF
0:(* create a new file *)
filop.sFileName:=sFileName;
filop.eFileMode:=FILE.MODE.MRDWR;
filop.xExclusive:=TRUE;
filop( xExecute:=TRUE);
IF filop.xDone THEN
hFile:=filop.hFile;
uiFileStdState:=1;
END_IF
IF filop.xError THEN
(* error handling*)
;
END_IF
1:(* write text in the file *)
filwr.hFile:=hFile;
filwr.pBuffer:=ADR(sFileTestString);
szFileSize1:=SIZEOF(sFileTestString);
filwr.szSize:=szFileSize1;
filwr.udiTimeOut:=100000; (* 100ms Timeout *)
filwr( xExecute:=TRUE);
IF filwr.xDone THEN
uiFileStdState:=2;
END_IF
IF filwr.xError THEN
(* error handling*)
;
END_IF
2:(* set the internal positon file pointer *)
filsp.hFile:= hFile;
filsp.udiPos:=0;
filsp( xExecute:=TRUE);
IF filsp.xDone THEN
uiFileStdState:=3;
END_IF
IF filsp.xError THEN
(* error handling*)
;
END_IF
3:(* read file - TestFile.txt*)
filrd.hFile:=hFile;
filrd.udiTimeOut:=100000; (* 100ms Timeout *)
filrd.pBuffer:=ADR(sFileString);
filrd.szBuffer:=SIZEOF (sFileString);
filrd( xExecute:=TRUE);
IF filrd.xDone THEN
szFileSize2:=filrd.szSize;
IF szFileSize2 = szFileSize1 THEN
uiFileStdState:=4;
ELSE
(* error handling*)
;
END_IF
END_IF
IF filrd.xError THEN
(* error handling*)
;
END_IF
4:(* close file - TestFile.txt *)
filcl.hFile:=hFile;
filcl( xExecute:=TRUE);
IF filcl.xDone THEN
uiFileStdState:=4;
END_IF
IF filcl.xError THEN
(* error handling*)
;
END_IF
5:(* end of example *)
;
END_CASE
END_IF
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