运行程序时终端挂起

Question

Have written some code in unix which counts the number of words in argv[1] via a function. The result is returned and displayed on stdout.

When I run it, the process just keeps on going until I kill it. NO errors show or anything? Would anyone mind just having a look.

THanks

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>

//function declaration
int countWords(char []);

int main(int argc, char* argv [])
{
  int words;

  //check 3 entered values
  if (argc != 3)
  {
    write(2,"Please enter 2 values. Seperated by Space \n", 44);
    exit(0);
  }

  words = countWords(argv[1]);
  printf("Words are %i \n", words);
  return 0;
}

//function to count words
int countWords(char a [])
{
  int counter, openStream, oTest;
  char letter;

  openStream = open(a,O_RDONLY);
  if (openStream < 0)
  {
    write(2, "Error opening specified file. \n", 32); 
    exit(1);
  }

  oTest = read(openStream, &letter, 1);
  while (oTest != 0)
  {
    if (oTest == -1)
    {
      write(2, "Error reading file \n",21);
      exit(2);
    } 
    if (oTest == '\n' || oTest == ' ')
    {
      counter++;
    }
  }
  close(openStream);
  return counter;
}

Answer 1

您正在循环，而输入流中仍有剩余内容，但是您实际上从未从循环中的输入流中读取内容 ，这意味着您的输入流永远并且永远都超过它的第一个字符，而oTest （第一个字符）从不变化。