SQLGetEnvAttr

// ODBC32.dll
#include <windows.h>

SHORT SQLGetEnvAttr(
    void* EnvironmentHandle,
    INT Attribute,
    void* Value,
    INT BufferLength,
    INT* StringLength   // optional
);

<DllImport("ODBC32.dll", ExactSpelling:=True)>
Public Shared Function SQLGetEnvAttr(
    EnvironmentHandle As IntPtr,   ' void* in/out
    Attribute As Integer,   ' INT
    Value As IntPtr,   ' void* out
    BufferLength As Integer,   ' INT
    StringLength As IntPtr   ' INT* optional, out
) As Short
End Function

' EnvironmentHandle : void* in/out
' Attribute : INT
' Value : void* out
' BufferLength : INT
' StringLength : INT* optional, out
Declare PtrSafe Function SQLGetEnvAttr Lib "odbc32" ( _
    ByVal EnvironmentHandle As LongPtr, _
    ByVal Attribute As Long, _
    ByVal Value As LongPtr, _
    ByVal BufferLength As Long, _
    ByVal StringLength As LongPtr) As Integer
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

SQLGetEnvAttr = ctypes.windll.odbc32.SQLGetEnvAttr
SQLGetEnvAttr.restype = ctypes.c_short
SQLGetEnvAttr.argtypes = [
    ctypes.POINTER(None),  # EnvironmentHandle : void* in/out
    ctypes.c_int,  # Attribute : INT
    ctypes.POINTER(None),  # Value : void* out
    ctypes.c_int,  # BufferLength : INT
    ctypes.POINTER(ctypes.c_int),  # StringLength : INT* optional, out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('ODBC32.dll')
SQLGetEnvAttr = Fiddle::Function.new(
  lib['SQLGetEnvAttr'],
  [
    Fiddle::TYPE_VOIDP,  # EnvironmentHandle : void* in/out
    Fiddle::TYPE_INT,  # Attribute : INT
    Fiddle::TYPE_VOIDP,  # Value : void* out
    Fiddle::TYPE_INT,  # BufferLength : INT
    Fiddle::TYPE_VOIDP,  # StringLength : INT* optional, out
  ],
  Fiddle::TYPE_SHORT)

#[link(name = "odbc32")]
extern "system" {
    fn SQLGetEnvAttr(
        EnvironmentHandle: *mut (),  // void* in/out
        Attribute: i32,  // INT
        Value: *mut (),  // void* out
        BufferLength: i32,  // INT
        StringLength: *mut i32  // INT* optional, out
    ) -> i16;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("ODBC32.dll")]
public static extern short SQLGetEnvAttr(IntPtr EnvironmentHandle, int Attribute, IntPtr Value, int BufferLength, IntPtr StringLength);
"@
$api = Add-Type -MemberDefinition $sig -Name 'ODBC32_SQLGetEnvAttr' -Namespace Win32 -PassThru
# $api::SQLGetEnvAttr(EnvironmentHandle, Attribute, Value, BufferLength, StringLength)

#uselib "ODBC32.dll"
#func global SQLGetEnvAttr "SQLGetEnvAttr" sptr, sptr, sptr, sptr, sptr
; SQLGetEnvAttr EnvironmentHandle, Attribute, Value, BufferLength, varptr(StringLength)   ; 戻り値は stat
; EnvironmentHandle : void* in/out -> "sptr"
; Attribute : INT -> "sptr"
; Value : void* out -> "sptr"
; BufferLength : INT -> "sptr"
; StringLength : INT* optional, out -> "sptr"
; ※HSP3.7は #func のため戻り値はシステム変数 stat に格納されます。

#uselib "ODBC32.dll"
#cfunc global SQLGetEnvAttr "SQLGetEnvAttr" sptr, int, sptr, int, var
; res = SQLGetEnvAttr(EnvironmentHandle, Attribute, Value, BufferLength, StringLength)
; EnvironmentHandle : void* in/out -> "sptr"
; Attribute : INT -> "int"
; Value : void* out -> "sptr"
; BufferLength : INT -> "int"
; StringLength : INT* optional, out -> "var"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

; SHORT SQLGetEnvAttr(void* EnvironmentHandle, INT Attribute, void* Value, INT BufferLength, INT* StringLength)
#uselib "ODBC32.dll"
#cfunc global SQLGetEnvAttr "SQLGetEnvAttr" intptr, int, intptr, int, var
; res = SQLGetEnvAttr(EnvironmentHandle, Attribute, Value, BufferLength, StringLength)
; EnvironmentHandle : void* in/out -> "intptr"
; Attribute : INT -> "int"
; Value : void* out -> "intptr"
; BufferLength : INT -> "int"
; StringLength : INT* optional, out -> "var"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

import (
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	odbc32 = windows.NewLazySystemDLL("ODBC32.dll")
	procSQLGetEnvAttr = odbc32.NewProc("SQLGetEnvAttr")
)

// EnvironmentHandle (void* in/out), Attribute (INT), Value (void* out), BufferLength (INT), StringLength (INT* optional, out)
r1, _, err := procSQLGetEnvAttr.Call(
	uintptr(EnvironmentHandle),
	uintptr(Attribute),
	uintptr(Value),
	uintptr(BufferLength),
	uintptr(StringLength),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // SHORT

function SQLGetEnvAttr(
  EnvironmentHandle: Pointer;   // void* in/out
  Attribute: Integer;   // INT
  Value: Pointer;   // void* out
  BufferLength: Integer;   // INT
  StringLength: Pointer   // INT* optional, out
): Smallint; stdcall;
  external 'ODBC32.dll' name 'SQLGetEnvAttr';

result := DllCall("ODBC32\SQLGetEnvAttr"
    , "Ptr", EnvironmentHandle   ; void* in/out
    , "Int", Attribute   ; INT
    , "Ptr", Value   ; void* out
    , "Int", BufferLength   ; INT
    , "Ptr", StringLength   ; INT* optional, out
    , "Short")   ; return: SHORT

●SQLGetEnvAttr(EnvironmentHandle, Attribute, Value, BufferLength, StringLength) = DLL("ODBC32.dll", "int SQLGetEnvAttr(void*, int, void*, int, void*)")
# 呼び出し: SQLGetEnvAttr(EnvironmentHandle, Attribute, Value, BufferLength, StringLength)
# EnvironmentHandle : void* in/out -> "void*"
# Attribute : INT -> "int"
# Value : void* out -> "void*"
# BufferLength : INT -> "int"
# StringLength : INT* optional, out -> "void*"
# なでしこ1は32bit・ANSI(Shift_JIS)。文字列=char*(ANSI)、ポインタ/ハンドル=void*(4byte)。