Switch Input method on macOS

mac-input.m

#include <stdio.h>
#include <string.h>
#include <Carbon/Carbon.h>

int main(int nargs, char** argv) {
    if (nargs != 2) {
        fprintf(stderr, "%s (on|off)\n", argv[0]);
        return 1;
    }
    
    TISInputSourceRef is = NULL;
    if (strcmp(argv[1], "on") == 0) {
        NSString *locale = [[NSLocale currentLocale] localeIdentifier];
        is = TISCopyInputSourceForLanguage(locale);
    } else if (strcmp(argv[1], "off") == 0) {
        is = TISCopyCurrentASCIICapableKeyboardInputSource();
    } else {
        fprintf(stderr, "%s (on|off)\n", argv[0]);
        return 1;
    }
    if (is) TISSelectInputSource(is);

    return 0;
}