accessing the osx clipboard via c++

build.sh

set -ex

clang -x objective-c -c osx.m -o osx.o
g++ -std=c++17 -c main.cpp -o main.o
g++ main.o osx.o -framework AppKit -o cliptest

capi.h

#pragma once

#ifdef __cplusplus
extern "C" {
#endif

void write_to_clipboard(const char* zero_terminated_string);

#ifdef __cplusplus
}
#endif

main.cpp

#include <iostream>
#include <array>
#include "capi.h"
using namespace std;

constexpr size_t BUFSIZE = 640 * 1024; // should be enough for everyone
array<char, BUFSIZE> buffer;

int main(int argc, char** argv) {
    cin.read(buffer.data(), buffer.size());
    write_to_clipboard(buffer.data());
    return 0;
}

osx.m

#import <AppKit/AppKit.h>

void write_to_clipboard(const char* zero_terminated_string) {
    NSPasteboard *pasteboard = [NSPasteboard generalPasteboard];
    NSString *string = [NSString stringWithUTF8String:zero_terminated_string];
    
    [pasteboard clearContents];
    [pasteboard setString:string forType:NSPasteboardTypeString];
}