#include<string.h>
#include<stdlib.h>
#include<stdio.h>
#include<unistd.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<fcntl.h>
#include<pthread.h>
#include <sys/types.h>
#include <signal.h>


int pipe_ends[2];
int read_end;
int write_end;

void handle_signal(int signal){
	char* message = "Caught the signal!\n";
	write(2, message, strlen(message));
}

void* run_system_in_other_thread(void* cmd){
	system(cmd); // Into the pipe here
	kill(getpid(), 13);
	close(write_end);
	close(read_end);
	return 0;
}

char* getoutput(char* cmd){
	pipe(pipe_ends);
	read_end = pipe_ends[0];
	write_end = pipe_ends[1];

	pid_t pid = fork();
	if(pid == 0){ // We're the child
		dup2(write_end, 1);
		close(read_end);
		execl("/bin/sh", "sh", "-c", cmd, (char *) 0);
		printf("Command was probably wrong\n");
	}
	// We must be the parent
	close(write_end);
	char *buffer = malloc(1024);
	size_t buffer_size = 1024;
	size_t totallen = 0;
	while(1){
		size_t readlen = read(read_end, buffer + totallen, buffer_size - totallen); // Out of the pipe here
		totallen += readlen;
		if(readlen < 1)
			break;
		if(buffer_size - totallen == 0){
			buffer = realloc(buffer, buffer_size + 1024);
			buffer_size += 1024;
		}
	}
	buffer[totallen] = 0;

	close(read_end);
	return buffer;

//	return "fish"; // ['f', 'i', 's', 'h', 0]
}

int main(){
	struct sigaction handler;
	handler.sa_handler = handle_signal;
	sigaction(13, &handler, 0);

	// A char* is not the same as a char
	char a_letter = 'a';
	char *text = getoutput("last");
//	char *text = getoutput("cat /usr/share/dict/american-english");
	printf("Size of char:  %d\nSize of char*:  %d\n", sizeof(a_letter), sizeof(text));
	printf("Length of text:  %d\n", strlen(text));
	puts(text);
	printf("Address of text: %lx (%lu)\n", text, text);

	free(text); 
	return 0;
}