68 lines
1.5 KiB
C++
68 lines
1.5 KiB
C++
#include <iostream>
|
|
#include <string>
|
|
#include <filesystem>
|
|
#include <fstream>
|
|
|
|
using std::cout;
|
|
namespace fs = std::filesystem;
|
|
|
|
bool is_jpeg(const unsigned char* buf);
|
|
bool is_png(const unsigned char* buf);
|
|
|
|
int main(int argc, char *argv[]) {
|
|
for (int i = 0; i <= argc - 1; i++) {
|
|
std::string arg = argv[i];
|
|
if (arg == "--help" || arg == "-h") {
|
|
cout << "help flag detected!";
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
if (argc != 2) {
|
|
cout << "Please specify image file. " << argv[0] << " imagefile.jpg";
|
|
return 1;
|
|
}
|
|
|
|
std::string imagefile = argv[1];
|
|
cout << "File: " << imagefile << "\n";
|
|
|
|
if (!fs::is_regular_file(imagefile)) {
|
|
std::cout << "File not found: " << imagefile << "\n";
|
|
return 1;
|
|
}
|
|
|
|
std::ifstream file(imagefile, std::ios::binary);
|
|
if (!file) {
|
|
cout << "Cannot open file!\n";
|
|
return 1;
|
|
}
|
|
|
|
unsigned char header[8];
|
|
file.read(reinterpret_cast<char*>(header), 8);
|
|
|
|
if (is_png(header)) {
|
|
cout << "PNG detected\n";
|
|
} else if (is_jpeg(header)) {
|
|
cout << "JPEG detected\n";
|
|
} else {
|
|
cout << "Unkown format!\n";
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
bool is_jpeg(const unsigned char* buf) {
|
|
return buf[0] == 0xFF && buf[1] == 0xD8 && buf[2] == 0xFF;
|
|
}
|
|
|
|
bool is_png(const unsigned char* buf) {
|
|
return buf[0] == 0x89 &&
|
|
buf[1] == 0x50 &&
|
|
buf[2] == 0x4E &&
|
|
buf[3] == 0x47 &&
|
|
buf[4] == 0x0D &&
|
|
buf[5] == 0x0A &&
|
|
buf[6] == 0x1A &&
|
|
buf[7] == 0x0A;
|
|
}
|