builtins.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <limits.h>
#include <dirent.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
// #include <time.h>

#include "builtins.h"

/*
 * This file contains all bultin functions. Except, maybe, ls.
 * Built-in functions include cd, pwd, exit.
 */

int shcd(char **argv, int argc) {

  char *location;
  if (argc == 1) {
    location = "~";
  }
  else {
    location = argv[1];
  }

  if (strcmp(location, "~") == 0) {
    location = getenv("HOME");
  }

  if(chdir(location) == -1) {
    perror("Could not cd into specified directory");
  }
  return 1;
}

int shpwd() {
  char *cdir = (char*)malloc(PATH_MAX * sizeof(char*));
  getcwd(cdir, PATH_MAX);

  printf("%s ", cdir);
  return 1;
}

int shexit() {
  return 0;
}

// Basic echo. No support for double quoted shit
int shecho(char **argv, int argc) {
  int i;
  // char *temp;
  for(i = 1; i < argc; i++) {
    // temp = argv[i];
    printf("%s", argv[i]);
  }
  printf("\n");
  return 1;
}



int remind(char **argv, int argc) {
  if(argc <= 2) {
    printf("Usage: remindme time reminder\n");
    return 1;
  }
  int time;
  time = strtol(argv[1], (char**)NULL, 10);
  char *text = (char*)malloc(4096*sizeof(char));
  int i;
  strcpy(text, argv[2]);
  // printf("no\n");
  for(i = 3; i < argc; i++) {
    strcat(text, " ");
    strcat(text, argv[i]);
  }
  strcat(text, "\0");
  switch (fork()) {
    case 0:
      sleep(time);
      printf("\n\nReminder: %s\n", text);
      break;
  }
  return 1;
}


int shsetenv(char **argv, int argc) {
  char* val;
  // int ret;
  if (argc != 2 && argc!= 3) {
    printf("Usage: setenv var [value]\n");
    return 1;
  }

  if (argc == 2) {
    val = "";
  }
  else {
    val = argv[2];
  }

  return setenv(argv[1], val, 1)==0?1:0;
}

int shunsetenv(char **argv, int argc) {
  if (argc != 2) {
    printf("Usage: unsetenv var\n");
    return 1;
  }

  return unsetenv(argv[1])==0?1:0;
}