c++ - system() 函数找不到可执行文件的可能原因是什么？

Question

  if( system("tail -500 log.txt") == -1)
  {
      //Error calling tail.exe on log 
      //errno is a system macro that expands int returning
      //the last error. strerror() converts the error to it's
      //corresponding error message. 
      printf("Error calling tail.exe with system(): %s",strerror( errno ));

  }

System()正在用 log.txt 调用 Tail.exe
所有都与调用它的可执行文件位于同一目录中。
收到错误 ENOENT- No such file or directory
此外，指定所有内容的路径，同样的错误。

感谢任何建议，谢谢。

Answer 1

来自您链接的 system() 上的文档:

ENOENT Command interpreter cannot be found.

所以问题不是找不到tail.exe，而是找不到命令解释器。这表明有更大的问题出了问题。我们需要更多信息来诊断真正的问题。同样来自同一页面:

The system function passes command to the command interpreter, which executes the string as an operating-system command. system refers to the COMSPEC and PATH environment variables that locate the command-interpreter file (the file named CMD.EXE in Windows NT and later). If command is NULL, the function simply checks to see whether the command interpreter exists.

这表明了一些调查途径:system(NULL) 返回什么？当您的程序运行时，COMSPEC 和 PATH 环境变量的值是多少？