Trabalho 5 de SO2

przombie.c

#include <sys/types.h>
#include <dirent.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/stat.h>
#include <string.h>
#include <stdbool.h>
#include <unistd.h>
#include <signal.h>

#define TAM_LINHA 256

static bool done = false;
static FILE* logFile = NULL;

void catch_sigterm(int param) {
  fprintf(logFile, "Terminating...\n");
  done = true;
}

int detect_zombies(void) {
  
  DIR* procDir = opendir("/proc");

  struct dirent* cur = NULL;

  while ((cur = readdir(procDir)) != NULL) {
    /* monta no do diretorio */
    char* buf = (char*) calloc(strlen("/proc/") + strlen(cur->d_name) + 1, sizeof(char));
    strcat(buf, "/proc/");
    strcat(buf, cur->d_name);
   
    /* verifica se eh diretorio */
    struct stat pidDir;
    if (stat(buf, &pidDir) == -1) {
      perror("stat");
      return 1;
    }

    free(buf);

    if (!S_ISDIR(pidDir.st_mode)) {
      continue;
    }
    
    /* converte o nome do diretorio para pid_t */
    pid_t pid = strtol(cur->d_name, NULL, 10);
    
    if (pid == 0 || errno == ERANGE) {
      continue;
    }

    /* ler o arquivo status e ver se eh zombie */
    buf = (char *) calloc(strlen("/proc/") + strlen(cur->d_name) + strlen("/status"), sizeof(char));
    strcat(buf, "/proc/");
    strcat(buf, cur->d_name);
    strcat(buf, "/status");

    FILE* statusFile = fopen(buf, "r");
    if (statusFile == NULL) {
      perror("fopen");
      return 1;
    }

    char linha[TAM_LINHA];

    bool isZombie = false;
    pid_t ppid = 0;
    char name[TAM_LINHA];

    while (fgets(linha, TAM_LINHA, statusFile) != NULL) {
      if (strstr(linha, "Z (zombie)") != NULL) {
        isZombie = true;
      }
      
      if (strstr(linha, "PPid") != NULL) {
        sscanf(linha, "PPid: %d", &ppid);
      }

      if (strstr(linha, "Name") != NULL) {
        sscanf(linha, "Name: %s", name);
      }
    }

    fclose(statusFile);

    if (isZombie) {
      fprintf (logFile, "%d \t %d \t %s\n", pid, ppid, name);
    }
  }

  closedir(procDir);

  return 0;
}

int main(void) {

  signal(SIGTERM, catch_sigterm);
  logFile = fopen("./daemon.log", "w+");

  fprintf(logFile, "PID \t PPID \t Programa\n");

  while (!done) {
    fprintf(logFile, "=========================\n");
    detect_zombies();
    fprintf(logFile, "=========================\n");
    sleep(3);

    fflush(logFile);
  }

  fclose(logFile);

  return 0;
}