Locating Subdirectory with _dos_findfirst & _dos_findnext

MS-DOS                      | OS/2            | WINDOWS

The information in this article applies to:

• The C Run-time (CRT), included with:

      - Microsoft C for MS-DOS, versions 5.1, 6.0, 6.0a, and 6.0ax
      - Microsoft C for OS/2, versions 5.1, 6.0, and 6.0a
      - Microsoft C/C++ for MS-DOS, version 7.0
      - Microsoft Visual C++ for Windows, versions 1.0 and 1.5
  

SUMMARY

When the attribute argument to the _dos_findfirst() and _dos_findnext() functions is either _A_RDONLY, _A_HIDDEN, _A_SYSTEM, or _A_SUBDIR, the functions will return all normal-attribute files. A normal-attribute file is any file that does not have a read-only, hidden, system, or directory attribute.

Thus, the following function call will return either a normal file or a subdirectory:

   _dos_findfirst( "*.*", _A_SUBDIR, &c_file )

MORE INFORMATION

To verify that the returned c_file is a subdirectory, check the attribute field of the c_file to determine whether the _A_SUBDIR bit is set. If so, then it is a subdirectory. This process may be accomplished by doing a bitwise-and of c_file.attrib with _A_SUBDIR and checking for a nonzero result.

The following program illustrates the use of these functions:

#include <dos.h>
#include <stdio.h>

        struct find_t c_file;

        _dos_findfirst( "*.*", _A_SUBDIR, &c_file );

        if( c_file.attrib & _A_SUBDIR )
        printf( "Directory listing %s\n", c_file.name );

        while (_dos_findnext(&c_file) == 0)
            if( c_file.attrib & _A_SUBDIR )
            printf( "Directory listing %s\n", c_file.name );
}