#include <stdlib.h>
#include <stdio.h>
#include <memory.h>
#include <dirent.h>
#include <string.h>
#include <signal.h>
#include <ctype.h>
int exit_signal;
char *killing_name;

void fail(char *str)
{
	free(killing_name);
	fprintf(stderr, "killall: process is ended: %s\n", str);
	exit(EXIT_FAILURE);
}
void cant_kill(char *str, int pid)
{
	fprintf(stderr, "Can't kill process   %s with pid = %d\n", str, pid);
}
void *safe_malloc(int size)
{
	void* res = malloc(size);
	if (res == NULL)
		fail("Out of memory");
	return res;
}
void *safe_realloc(void* adress, int new_size)
{
	void* temp = realloc(adress, new_size);
	if (temp == NULL)
		fail("Out of memory");
	return temp;
}
void parser(int argc, char **argv)
{
	if (argc != 3)
	        fail("Wrong params");
	int i = 0;
	char *end;
	exit_signal = strtoul(argv[1], &end, 10);
	if (*end == 0)
		fail("Wrong params");
	sprintf(killing_name, "(%s)", argv[2]);
}
int max(int a, int b)
{
	return a > b? a: b;
}
char is_process(char str[256])
{
	int i = 0;
	while (i != 256 && str[i] != '\0')
	{
		if (!isdigit(str[i]))
			return 0;
		i++;
	}
	return 1;
}
char *get_stat(char* process_name)
{
	char *result = safe_malloc(strlen(process_name) + 15);
	sprintf(result, "/proc/%s/stat", process_name);
	return result;
}
void killall(int code, char* name)
{
	DIR *dir = opendir("/proc");
	FILE* file;
	struct dirent *curr;
	char  *file_name, *buf;
	char  process_name[256];
	int pid;
	char result_of_killing;
	while ((curr = readdir(dir)) != NULL)
	{
		if (is_process(curr->d_name))
		{
			file_name = get_stat(curr->d_name);
			//getting pid and name
			file = fopen(file_name, "r");
			if (file != NULL)
			{
				fscanf(file, "%d\n%s\n", &pid, process_name);
				if (strcmp(process_name, killing_name) == 0)
				{
					result_of_killing = kill(pid, exit_signal);
					if (result_of_killing == 0)
						cant_kill(process_name, pid);
				}
				fclose(file);
			}
		}
	}
}
void allocating_memory(int argc, char **argv)
{
	int i, j, size = 0;
        for (i = 1; i < argc; i++)
        {
                j = 0;
                while (argv[i][j] != '\0')
                        j++;
                size = max(size, j);
        }
	killing_name = safe_malloc(size * sizeof(char) + 3);// +'(' + ')' + '\0'

}
int main(int argc, char **argv)
{
	allocating_memory(argc, argv);
	parser(argc, argv);
	killall(exit_signal, killing_name);
	free(killing_name);
	return EXIT_SUCCESS;
}