在UNIX中将文件从一个位置移动到另一个位置

Question

I have to implement a shell in unix with some commands

I want to move multiple files into a folder location like mv -t does.

The problem is that rename function, just rename a file dont move that file.

void mv_t()
{
  int mutat;
  char mvFile_name1[256];
  char mvFile_name2[256];
  int nr=0;

  printf("How many files you want to move: ");
  fflush(stdin);
  scanf("%d", &nr);

  printf("The file where you move: ");
  fflush(stdin);
  scanf("%s", &mvFile_name1);

  for(i=0; i<nr; i++)
  {
    printf("The file you want to move: ");
    fflush(stdin);
    scanf("%s", &mvFile_name2);

    mutat = rename(mvFile_name1, mvFile_name2);
    if(mutat != 0)
      perror("Error");
  }
}

This is what I wrote. In "for" he take mvFile_name1 and rename it as mvFile_name2, and then he don't have the previous name for the file. But if this will work, still don't move the files in the mvFile_name1, he just rename them like mvFile_name1.

Answer 1

You have your args to rename() in the wrong order, swap them.

They are:

rename(oldpath, newpath);

Also you need to construct the newpath by striping off any path (part before a /) in the mvFile_name2 and replacing that with mvFile_name1.

Also you should verify that mvFile_name1 is a directory.

So if the person enters:

1
/tmp
/some/place/this.txt

then you should do:

rename(/some/place/this.txt, /tmp/this.txt);

Also if the oldpath and the newpath are on different disks, this will fail, but that may be more complication than you want to deal with.

Also, everything that @iharob said.

Answer 2

Even if your code worked, it has some problems

1. The fflush() function's behavior is not defined for input streams in the c standard, only for output. Thus, fflush(stdin) is undefined behavior.

2. You must check scanf() 's return value, not doing so might cause problems specially for the "%d" specifier.

3. This scanf("%s", &mvFile_name1); is wrong because mvFile_name1 is already a pointer to the first element of the array. Passing it's address is wrong because the resulting pointer has the wrong type.