CS456 - Systems Programming

Displaying exercises/e6/files/main.c

#include "lex.h"

#define BUFSIZE	64*1024

char *tstring[] = {
  "string", "number", "[", "]", "{", "}", ",", ":", "true", "false", "null",
  "EOI", "?"
};

char *readfile(char *path)
{
  int fd = open(path, O_RDONLY);
  if (fd < 0) {
    perror("open");
    return NULL;
  }

  struct stat st;
  if (fstat(fd, &st) < 0) {
    perror("stat");
    return NULL;
  }

  char *data = malloc(st.st_size+1);

  size_t r;
  if ((r = read(fd, data, st.st_size)) != st.st_size) {
    printf("Short read, returned = %ld, expected = %ld\n", r, st.st_size);
    free(data);
    return NULL;
  }
  data[st.st_size] = '\0';
  close(fd);

  return data;
}

/**
 * This program is not for you to modify.  It is used for testing your lexer
 * library.  Use 'make test' to compile this program against your lexer and
 * test it.
 */
int main(int argc, char *argv[])
{
  if (argc < 2) {
    printf("Usage: %s <file>\n", argv[0]);
    return 1;
  }

  char *filedata = readfile(argv[1]);
  if (filedata == NULL) return 1;

  token_t tok;
  char wbuf[BUFSIZE];

  startlex(filedata);
  while((tok = lex(wbuf)) != T_EOI) {
    switch(tok) {
      case T_STRING:
      case T_NUMBER:
	printf("%s: %s\n", tstring[tok], wbuf);
	break;
      default:
	printf("token: %s\n", tstring[tok]);
	break;
    }
  }

  return 0;
}