Can't pass string with spaces to ShellExecuteA in C-CodePudding

I try to pass a file path to ShellExecuteA. It doesn't work when the path contain spaces. I pass the file path to another application of mine and then do something with the path.

test.exe:

delFp[200] = "del \"C:\\Users\\John Doe\\Documents\\Winsock\\Winsock\\x64\\Release\\test.exe\"";
    ShellExecuteA(
        NULL,
        NULL,
        "MyOtherApplication.exe",
        delFp,
        NULL,
        SW_SHOW);

This is whay I do in MyOtherApplication.exe:

if (strncmp(argv[1], "del", 3) == 0)
    {
        printf("Deleting origin...\n");
        Sleep(1000);
        str_cut(argv[1], 0, 3);
        char del[200];
        strcat_s(del, 200, "del \"");
        strcat_s(del, 200, argv[1]);
        strcat_s(del, 200, "\"");
        system(del); // Delete test.exe (not this program but the other one)
    }

CodePudding user response：

There are multiple problems:

You did not post the definition of str_cut, but you only remove 3 bytes from the beginning of the string whereas you should also skip or remove the spaces between del and the argument.
you should use strcpy_s to copy the first string to the destination array del. As this array is uninitialized, strcat_s() might not copy the string at the beginning.
if the argv[1] string already contains double quotes, you should not add an extra set.

Try this:

    char *p = argv[1];
    if (strncmp(p, "del", 3) == 0 && isspace((unsigned char)p[3])) {
        printf("Deleting origin...\n");
        Sleep(1000);
        p  = 4;
        while (isspace((unsigned char)*p))
            p  ;
        char del[200];
        if (*p == '"') {
            // no quotes needed
            strcpy_s(del, sizeof del, "del ");
            strcat_s(del, sizeof del, p);
        } else {
            strcpy_s(del, sizeof del, "del \"");
            strcat_s(del, sizeof del, p);
            strcat_s(del, sizeof del, "\"");
        }
        system(del);
    }

Note these remarks:

you should use the remove function defined in <stdio.h> to remove the file, instead of running the shell.
it might be impossible to remove an executable file that is currently running on some legacy systems.

you should use snprintf to compose the command strings:

  int len;
  if (*p == '"') {
      // no quotes needed
      len = snprintf(del, sizeof del, "del %s", p);
  } else {
      len = snprintf(del, sizeof del, "del \"%s\"", p);
  }
  if (len >= (int)sizeof(del)) {
      fprintf(stderr, "filename too long: %s\n", p);
  } else {
      system(del);
  }