C to PB Help needed

[Neil J Hosgood]

Hi, C code below seems straight forward but I am getting stuck on the
correct declaration of the argv parameter. any help please ?

int __declspec(dllexport)	__stdcall	DBFtoCSV_Converter(HWND hwnd, int argc, char *argv[]);

int
main()
{
	int		n=0;
	char	*params[10];

	params[n++]=strdup(__argv[0]);
	params[n++]=strdup("source.dbf");
	params[n++]=strdup("target.csv");
	params[n++]=strdup("/ansi");
	params[n++]=strdup("/overwrite=0");

	return DBFtoCSV_Converter(NULL, n, params);
}

[Michael Mattias]

http://docs.codegear.com/docs/radstudio/radstudio2007/RS2007_helpupdates/HUpdate4/EN/html/devwin32/_argv_xml.html

Thank you, Google.

[Neil J Hosgood]

Thanks Michael, kinda figured it was an array pointer, but string or asciiz?.
whats the best way to declare it? or just declare as dword ?

N.

[José Roca]

The command line arguments is an array of string, so declare it as BYREF STRING.

[Neil J Hosgood]

ok, you'll have to excuse my ignorance, am I delcaring as
byref argv as string ptr and passing a pointer to the first element?
or delcaring as byref argv() as string ptr ?


ta,
N.

[José Roca]

No. You have to declare it as BYREF argv AS STRING and pass a pointer to the first element of the array, that you will do passing argv(0).

[Michael Mattias]

>>DBFtoCSV_Converter(HWND hwnd, int argc, char *argv[]);

>BYREF argv AS STRING


"BYREF as String" passes the address of an OLE string handle, "char * argv[]" wants the address of the first byte of a (small a) array of null-terminated strings.

DECLARE FUNCTION DBFtoCSV_Converter LIB "whatver.dll"  [ALIAS "whatever"] (BYVAL hwnd AS LONG, BYVAL argc AS LONG, BYVAL argv aS DWORD) AS LONG
 .......
   LOCAL arvg AS STRING 
   argv =  Param1 & $NUL & PARAM2 & $NUL [& paramN & $NUL]...
  

   CALL DbftoCSV_Converter (hWnd, arcg, BYVAL STRPTR (argv))

MCM

[José Roca]

"char * argv[]" wants the address of the first byte of a (small a) array of null-terminated strings.

No, it wants a pointer to an array of string pointers.
argv[] is an array and char * is a pointer to a byte string.
OLE strings are also null-terminated, so can be used for the purpose.

[Michael Mattias]

_argv, _wargvHeader File 

stdlib.h 

Syntax 

extern char **_argv; 

extern wchar_t ** _wargv

Oops, I missed that second '*' preceding the _argv

However, passing "BYREF AS STRING" should still be passing the address of the string descriptor.

But since what is at VARPTR(ole string) is the address of the string data, I guess it will work OK. (But that does not mean I would be real comfy doing that.... at least not without some extensive commenting in my source code).


MCM

[Ian Cairns]

dBase III/IV source code

Neil, it looks like you might be doing work with dBase files. If you would like a dBase III/IV file viewer (listview output) with complete source code, drop me a line at ian[dot][email protected][dot]bc[dot]ca. (one of my more requested projects).

regards, Ian.

[Michael Mattias]

If there is an OLE provider for dBase (and I'm sure there is), converting a dbase database to a CSV file is probably less than 20 lines of PB code using ADO.

[Cliff Nichols]

Neil,
Maybe not as close as you would like but maybe a step forward as to how the parameter is passed to you.

Get that Data Type in the source code forums.

I will admit, its just a beginning, and as Jose will point out, numeric data is sometimes incorrect (but correct as in functional)

aka, from what I got from PB, if I declare byte, but the passed value is byte, my guessing is the passed data is LONG (unless the value is beyond the parameters of BYTE)

Still working on it, but maybe something useful

[Neil J Hosgood]

Thanks Ian, I have a lot of accounting data to convert over the next two months (data is all VFP dbf). I did start coding the extract stuff but have problems getting the correct field count, when I add the 263 byte buffer into the equation it works for some files but not others, when I remove it from the equation it works for the others. They are all reporting the correct VFP file type in the header....
Normally I just export the data usinf CDBFW and run 20 or so queries in excel to give me the import data but this time I have 7 companies to convert all one April 1st (new financial year) so I am trying to automate everything.

Will try methods from Jose and see where it gets me, failing that will post my own code and see if anyone can pick whats wrong

[Fred Harris]

The ultimate purpose of these variables...

int argc, char *argv[]

is to extract the command line arguments passed to the program. I doubt that in this code the programmer created those variables. So, if you are going to be converting a C prog to PB, you'll be using PB's Command$ syntax to retrieve whatever is passed in as a command tail. If the command tail has several arguements you'll have to parse them. Here is a simple example of how those variables are used in a C or C++ program named 'testing' if you execute the program like this...

C:\testing one two three [ENTER]

C:\Code>testing one two three

argc = 4

0       testing
1       one
2       two
3       three

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char* argv[])
{
 printf("\nargc = %u\n\n",argc);
 for(int i=0;i<argc;i++)
     printf("%u\t%s\n",i,argv[i]);
 getchar();

 return 0;
}

[Neil J Hosgood]

Thanks Fred, in this case it is a dll with a single function, see c++ calling below:

int __declspec(dllexport)	__stdcall	DBFtoCSV_Converter(HWND hwnd, int argc, char *argv[]);

int
main()
{
	int     n=0;
	char    *params[10];

	params[n++]=strdup(__argv[0]);
	params[n++]=strdup("source.dbf");
	params[n++]=strdup("target.csv");
	params[n++]=strdup("/ansi");
	params[n++]=strdup("/overwrite=0");

	return DBFtoCSV_Converter(NULL, n, params);
}

[Fred Harris]

argv[0] is the name of the program that was executed; in my case above you can see it was 'testing.exe' but I just executed it as 'testing'. Other than that I'm not sure what is going on there, that is, why that would be a valuable piece of info to pass on to the function call at bottom?

return DBFtoCSV_Converter(NULL, n, params);

params would point to the beginning of the null terminated char* array, so DBFtoCSV converter would end up getting the string name of the host program that loaded the dll? Or am I off track? Other than that, none of the other info in argc or argv[] is being passed to DBFtoCSV_Converter.

[Neil J Hosgood]

HI Fred,
In PB it would be something like this (using NULL sparated args),
just cant get it to work.

DECLARE FUNCTION DBFtoCSV_Converter LIB "dbf2csv_d.dll" ALIAS "DBFtoCSV_Converter"(BYVAL hwnd AS LONG, BYVAL argc AS LONG, BYREF argv AS STRING) AS LONG

FUNCTION PBMAIN () AS LONG
  DIM sArgs AS STRING 
  LOCAL lRet AS LONG
  LOCAL lCount AS LONG

 sArgs = "cl.dbf" & CHR$(0) & "cl.csv" & CHR$(0) & "/REMCRLF=1" & CHR$(0) & "/OVERWRITE=1" & CHR$(0) & "/QUOTES=1" & CHR$(0) & "/HEADER=1"

 nCount = 6
 lRet =  DBFtoCSV_Converter( BYVAL %NULL , BYVAL nCount,  sArgs)


END FUNCTION

[José Roca]

Try

DIM sArgs (5) AS STRING

sArgs(0) = "cl.dbf"
sArgs(1) = "cl.csv"
sArgs(2) = "/REMCRLF=1"
sArgs(3) = "/OVERWRITE=1"
sArgs(4) = "/QUOTES=1"
sArgs(5) = "/HEADER=1"

nCount = 6
lRet =  DBFtoCSV_Converter( BYVAL %NULL , BYVAL nCount,  sArgs(0))

[Neil J Hosgood]

That did the trick, Many thanks.

N.