Experiments on MSVCRT's setlocale() and system()

dumparg.c

// dumparg.c
#include <stdio.h>
#include <wchar.h>
int wmain(int argc, const wchar_t *argv[])
{
    for (int i = 0; i < argc; ++i) {
        const wchar_t *s = argv[i];
        printf("argv[%d] = ", i);
        while (*s != 0) {
            if (*s < 0x80 && isprint(*s)) {
                printf("%02x(%c) ", (unsigned int)*s, (unsigned int)*s);
            } else {
                printf("%02x ", (unsigned int)*s);
            }
            s++;
        }
        puts("");
    }
}

localetest-classic.txt

C:\...> cl /Fe:localetest-classic.exe localetest.c
Microsoft (R) C/C++ Optimizing Compiler Version 18.00.31101 for x64
Copyright (C) Microsoft Corporation. All rights reserved.

localetest.c
Microsoft (R) Incremental Linker Version 12.00.31101.0
Copyright (C) Microsoft Corporation. All rights reserved.

/out:localetest-classic.exe
localetest.obj

C:\...> localetest-classic
LC_CTYPE = C
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = ff72 ff73
LC_CTYPE = C
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = ff72 ff73
setlocale(LC_CTYPE, "") succeeded
LC_CTYPE = Japanese_Japan.932
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = ff72 ff73
setlocale(LC_CTYPE, ".UTF-8") failed
LC_CTYPE = Japanese_Japan.932
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = 7e3a
setlocale(LC_CTYPE, "French_France") succeeded
LC_CTYPE = French_France.1252
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = ff72 ff73
setlocale(LC_CTYPE, ".UTF-8") failed
LC_CTYPE = French_France.1252
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = 7e3a
setlocale(LC_CTYPE, "Greek_Greece") succeeded
LC_CTYPE = Greek_Greece.1253
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = ff72 ff73
_setmbcp(_MB_CP_ANSI) succeeded
LC_CTYPE = Greek_Greece.1253
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = ff72 ff73
_setmbcp(_MB_CP_LOCALE) succeeded
LC_CTYPE = Greek_Greece.1253
mbcp = _MB_CP_SBCS
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = ff72 ff73
_setmbcp(_MB_CP_SBCS) succeeded
LC_CTYPE = Greek_Greece.1253
mbcp = _MB_CP_SBCS
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = ff72 ff73
_setmbcp(65001) failed
LC_CTYPE = Greek_Greece.1253
mbcp = _MB_CP_SBCS
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = 7e3a

localetest-ucrt-dynamic.txt

C:\...> cl /Fe:localetest-ucrt-dynamic.exe /MD localetest.c
Microsoft(R) C/C++ Optimizing Compiler Version 19.13.26129 for x64
Copyright (C) Microsoft Corporation. All rights reserved.

localetest.c
Microsoft (R) Incremental Linker Version 14.13.26129.0
Copyright (C) Microsoft Corporation. All rights reserved.

/out:localetest-ucrt-dynamic.exe
localetest.obj

C:\...> localetest-ucrt-dynamic
LC_CTYPE = C
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = b2 b3
LC_CTYPE = C
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = b2 b3
setlocale(LC_CTYPE, "") succeeded
LC_CTYPE = Japanese_Japan.932
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = ff72 ff73
setlocale(LC_CTYPE, ".UTF-8") succeeded
LC_CTYPE = Japanese_Japan.utf8
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = 3042
setlocale(LC_CTYPE, "French_France") succeeded
LC_CTYPE = French_France.1252
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = b2 b3
setlocale(LC_CTYPE, ".UTF-8") succeeded
LC_CTYPE = Japanese_Japan.utf8
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = 3042
setlocale(LC_CTYPE, "Greek_Greece") succeeded
LC_CTYPE = Greek_Greece.1253
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = b2 b3
_setmbcp(_MB_CP_ANSI) succeeded
LC_CTYPE = Greek_Greece.1253
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = b2 b3
_setmbcp(_MB_CP_LOCALE) succeeded
LC_CTYPE = Greek_Greece.1253
mbcp = _MB_CP_SBCS
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = b2 b3
_setmbcp(_MB_CP_SBCS) succeeded
LC_CTYPE = Greek_Greece.1253
mbcp = _MB_CP_SBCS
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = b2 b3
_setmbcp(65001) succeeded
LC_CTYPE = Greek_Greece.1253
mbcp = _MB_CP_SBCS
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = 3b3 81 201a

localetest-ucrt.txt

C:\...> cl /Fe:localetest-ucrt.exe localetest.c
Microsoft(R) C/C++ Optimizing Compiler Version 19.13.26129 for x64
Copyright (C) Microsoft Corporation. All rights reserved.

localetest.c
Microsoft (R) Incremental Linker Version 14.13.26129.0
Copyright (C) Microsoft Corporation. All rights reserved.

/out:localetest-ucrt.exe
localetest.obj

C:\...> localetest-ucrt
LC_CTYPE = C
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = ff72 ff73
LC_CTYPE = C
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = ff72 ff73
setlocale(LC_CTYPE, "") succeeded
LC_CTYPE = Japanese_Japan.932
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = ff72 ff73
setlocale(LC_CTYPE, ".UTF-8") failed
LC_CTYPE = Japanese_Japan.932
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = 7e3a
setlocale(LC_CTYPE, "French_France") succeeded
LC_CTYPE = French_France.1252
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = ff72 ff73
setlocale(LC_CTYPE, ".UTF-8") failed
LC_CTYPE = French_France.1252
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = 7e3a
setlocale(LC_CTYPE, "Greek_Greece") succeeded
LC_CTYPE = Greek_Greece.1253
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = ff72 ff73
_setmbcp(_MB_CP_ANSI) succeeded
LC_CTYPE = Greek_Greece.1253
mbcp = 932
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = ff72 ff73
_setmbcp(_MB_CP_LOCALE) succeeded
LC_CTYPE = Greek_Greece.1253
mbcp = _MB_CP_SBCS
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = ff72 ff73
_setmbcp(_MB_CP_SBCS) succeeded
LC_CTYPE = Greek_Greece.1253
mbcp = _MB_CP_SBCS
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = ff72 ff73
_setmbcp(65001) failed
LC_CTYPE = Greek_Greece.1253
mbcp = _MB_CP_SBCS
argv[0] = 64(d) 75(u) 6d(m) 70(p) 61(a) 72(r) 67(g) 2e(.) 65(e) 78(x) 65(e)
argv[1] = 7e3a

localetest.c

// localetest.c
#include <stdio.h>
#include <stdlib.h>
#include <locale.h>
#include <mbctype.h>
void printlocale(void)
{
    printf("LC_CTYPE = %s\n", setlocale(LC_CTYPE, NULL));
    int mbcp = _getmbcp();
    switch (mbcp) {
    case _MB_CP_ANSI: puts("mbcp = _MB_CP_ANSI"); break;
    case _MB_CP_LOCALE: puts("mbcp = _MB_CP_LOCALE"); break;
    case _MB_CP_OEM: puts("mbcp = _MB_CP_OEM"); break;
    case _MB_CP_SBCS: puts("mbcp = _MB_CP_SBCS"); break;
    default: printf("mbcp = %d\n", mbcp); break;
    }
}
int main(void)
{
    printlocale();
    system("dumparg.exe \xb2\xb3");

    setlocale(LC_CTYPE, "C");
    printlocale();
    system("dumparg.exe \xb2\xb3");

    printf("setlocale(LC_CTYPE, \"\") %s\n", setlocale(LC_CTYPE, "") != NULL ? "succeeded" : "failed");
    printlocale();
    system("dumparg.exe \xb2\xb3");

    printf("setlocale(LC_CTYPE, \".UTF-8\") %s\n", setlocale(LC_CTYPE, ".UTF-8") != NULL ? "succeeded" : "failed");
    printlocale();
    system("dumparg.exe \xe3\x81\x82");

    printf("setlocale(LC_CTYPE, \"French_France\") %s\n", setlocale(LC_CTYPE, "French_France") != NULL ? "succeeded" : "failed");
    printlocale();
    system("dumparg.exe \xb2\xb3");

    printf("setlocale(LC_CTYPE, \".UTF-8\") %s\n", setlocale(LC_CTYPE, ".UTF-8") != NULL ? "succeeded" : "failed");
    printlocale();
    system("dumparg.exe \xe3\x81\x82");

    printf("setlocale(LC_CTYPE, \"Greek_Greece\") %s\n", setlocale(LC_CTYPE, "Greek_Greece") != NULL ? "succeeded" : "failed");
    printlocale();
    system("dumparg.exe \xb2\xb3");

    printf("_setmbcp(_MB_CP_ANSI) %s\n", _setmbcp(_MB_CP_ANSI) >= 0 ? "succeeded" : "failed");
    printlocale();
    system("dumparg.exe \xb2\xb3");

    printf("_setmbcp(_MB_CP_LOCALE) %s\n", _setmbcp(_MB_CP_LOCALE) >= 0 ? "succeeded" : "failed");
    printlocale();
    system("dumparg.exe \xb2\xb3");

    printf("_setmbcp(_MB_CP_SBCS) %s\n", _setmbcp(_MB_CP_SBCS) >= 0 ? "succeeded" : "failed");
    printlocale();
    system("dumparg.exe \xb2\xb3");

    printf("_setmbcp(65001) %s\n", _setmbcp(65001) >= 0 ? "succeeded" : "failed");
    printlocale();
    system("dumparg.exe \xe3\x81\x82");
}