CONVDSN.C

/* 
** CONVDSN.C - This is the ODBC sample code for 
** creating File DSN pointers to machine DSNs. 
** 
**This code is furnished on an as-is basis as part of the ODBC SDK and is 
**intended for example purposes only. 
** 
*/ 
 
#include <windows.h> 
#include <stdio.h> 
#include "sql.h" 
#include "sqlext.h" 
#include "odbcinst.h" 
 
// prototypes 
 
void ExpandFileName(LPSTR szFileDSNName, LPCSTR szDSNName); 
void MakeLegalName(LPSTR szLegalDSNName, LPCSTR szDSNName); 
 
// main routine:  Iterate through the user and system DSNs, creating a pointer 
//                to each. 
 
int _stdcall WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, 
   LPSTR lpszCmdLine, int nCmdShow) 
{ 
HENV    henv; 
RETCODE retcode; 
CHAR    szDSNName[SQL_MAX_DSN_LENGTH + 1]; 
CHAR    szLegalDSNName[SQL_MAX_DSN_LENGTH + 1]; 
CHAR    szFileDSNName[MAX_PATH + 1]; 
 
if(SQL_SUCCEEDED(SQLAllocHandle(SQL_HANDLE_ENV, NULL, &henv))) 
{ 
// set the ODBC behavior version. 
(void) SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION, 
(SQLPOINTER) SQL_OV_ODBC3, SQL_IS_INTEGER); 
 
// Enumerate the user data sources. 
retcode = SQLDataSources(henv, SQL_FETCH_FIRST_SYSTEM, szDSNName, 
sizeof(szDSNName), NULL, NULL, 0, NULL); 
 
while(SQL_SUCCEEDED(retcode)) 
{ 
// Make a version of the name acceptable for use as a filename. 
MakeLegalName(szLegalDSNName, szDSNName); 
 
// Build the full filename. 
ExpandFileName(szFileDSNName, szLegalDSNName); 
 
// Write the DSN= keyword into the File DSN. 
SQLWriteFileDSN(szFileDSNName, "ODBC", "DSN", szDSNName); 
 
// Do the next one, if it exists. 
retcode = SQLDataSources(henv, SQL_FETCH_NEXT, szDSNName, 
sizeof(szDSNName), NULL, NULL, 0, NULL); 
} 
 
// Enumerate the system data sources. 
retcode = SQLDataSources(henv, SQL_FETCH_FIRST_USER, szDSNName, 
sizeof(szDSNName), NULL, NULL, 0, NULL); 
 
while(SQL_SUCCEEDED(retcode)) 
{ 
// Make a version of the name acceptable for use as a filename. 
MakeLegalName(szLegalDSNName, szDSNName); 
 
// Build the full filename. 
ExpandFileName(szFileDSNName, szLegalDSNName); 
 
// Write the DSN= keyword into the File DSN. 
SQLWriteFileDSN(szFileDSNName, "ODBC", "DSN", szDSNName); 
 
// Do the next one, if it exists. 
retcode = SQLDataSources(henv, SQL_FETCH_NEXT, szDSNName, 
sizeof(szDSNName), NULL, NULL, 0, NULL); 
} 
 
SQLFreeHandle(SQL_HANDLE_ENV, henv); 
} 
 
return 0; 
} 
 
// ExpandFileName:  Take the pieces of the filename, and form a complete 
//                  filename. 
 
void ExpandFileName(LPSTR szFileDSNName, LPCSTR szDSNName) 
{ 
strcpy(szFileDSNName, szDSNName); 
 
// Hint that we're not sharable 
strcat(szFileDSNName, " (not sharable)"); 
} 
 
// MakeLegalName:  Make a version of the DSN name suitable for use as a  
//                 filename. 
 
void MakeLegalName(LPSTR szLegalDSNName, LPCSTR szDSNName) 
{ 
CHAR   szIllegalChars[] = "\\/:*?\"<>|"; 
LPSTR  pchIllegalChar; 
LPCSTR pchDSNSource     = szDSNName; 
LPSTR  pchDSNTarget     = szLegalDSNName; 
BOOL   fIllegal; 
 
while(*pchDSNSource) 
{ 
pchIllegalChar = szIllegalChars; 
 
fIllegal = FALSE; 
 
// if the character is double byte, copy it and move ahead 
if(IsDBCSLeadByte(*pchDSNSource)) 
{ 
*(pchDSNTarget++) = *(pchDSNSource++); 
*(pchDSNTarget++) = *(pchDSNSource++); 
} 
else 
{ 
// single byte 
if(!isalpha(*pchDSNSource) && !isdigit(*pchDSNSource)) 
{ 
while(*pchIllegalChar) 
{ 
if(*pchDSNSource == *(pchIllegalChar++)) 
{ 
fIllegal = TRUE; 
break; 
} 
} 
} 
 
if(fIllegal) 
{ 
pchDSNSource++; 
} 
else 
{ 
*(pchDSNTarget++) = *(pchDSNSource++); 
} 
} 
} 
*pchDSNTarget = '\0'; 
}