main.c

/*
@author: Huzaifa Naseer
*/

#include "executor.h"
#include "parser.h"
#include "shell.h"
#include "source.h"
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(int argc, char **argv) {
  printf("\033[1;32m");
  printf("Welcome to my shell!\n");
  printf("This shell was created by @HuzaifaNaseer.\n");
  printf("Check out my GitHub: https://github.com/HN026\n");
  printf(
      "Connect with me on LinkedIn: https://linkedin.com/in/huzaifanaseer\n");
  printf("\033[0m");

  char *cmd;
  initsh();
  do {
    print_prompt1();
    cmd = read_cmd();

    if (!cmd) {
      exit(EXIT_SUCCESS);
    }

    if (cmd[0] == '\0' || strcmp(cmd, "\n") == 0) {
      free(cmd);
      continue;
    }

    if (strcmp(cmd, "exit\n") == 0) {
      free(cmd);
      break;
    }

    struct source_s src;
    src.buffer = cmd;
    src.bufsize = strlen(cmd);
    src.curpos = INIT_SRC_POS;
    parse_and_execute(&src);
  } while (1);

  exit(EXIT_SUCCESS);
}

char *read_cmd(void) {
  char buf[1024];
  char *ptr = NULL;
  char ptrlen = 0;

  while (fgets(buf, 1024, stdin)) {
    int buflen = strlen(buf);

    if (!ptr) {
      ptr = malloc(buflen + 1);
    } else {
      char *ptr2 = realloc(ptr, ptrlen + buflen + 1);

      if (ptr2) {
        ptr = ptr2;
      } else {
        free(ptr);
        ptr = NULL;
      }
    }

    if (!ptr) {
      fprintf(stderr, "error: failed to alloc buffer: %s\n", strerror(errno));
      return NULL;
    }

    strcpy(ptr + ptrlen, buf);

    if (buf[buflen - 1] == '\n') {
      if (buflen == 1 || buf[buflen - 2] != '\\') {
        return ptr;
      }

      ptr[ptrlen + buflen - 2] = '\0';
      buflen -= 2;
      print_prompt2();
    }
    ptrlen += buflen;
  }
  return ptr;
}

int parse_and_execute(struct source_s *src) {
  skip_white_spaces(src);

  struct token_s *tok = tokenize(src);

  if (tok == &eof_token) {
    return 0;
  }

  while (tok && tok != &eof_token) {
    struct node_s *cmd = parse_command(tok);
    if (!cmd) {
      break;
    }

    do_command(cmd);
    free_node_tree(cmd);
    tok = tokenize(src);
  }

  return 1;
}