# Path conversion functions

cygwin_conv_path
3
Cygwin API Reference

## cygwin_conv_path

    #include <sys/cygwin.h>

    ssize_t
    cygwin_conv_path
    cygwin_conv_path_t what
    const void * from
    void * to
    size_t size

### Description

Use this function to convert POSIX paths in `from` to Win32 paths in `to` or, vice versa, Win32 paths in `from` to POSIX paths in `to`. `what` defines the direction of this conversion and can be any of the below values.

      CCP_POSIX_TO_WIN_A      /* from is char *posix, to is char *win32       */
      CCP_POSIX_TO_WIN_W,     /* from is char *posix, to is wchar_t *win32    */
      CCP_WIN_A_TO_POSIX,     /* from is char *win32, to is char *posix       */
      CCP_WIN_W_TO_POSIX,     /* from is wchar_t *win32, to is char *posix    */

You can additionally or the following values to `what`, to define whether you want the resulting path in `to` to be absolute or if you want to keep relative paths in relative notation. Creating absolute paths is the default.

      CCP_ABSOLUTE = 0,         /* Request absolute path (default).             */
      CCP_RELATIVE = 0x100      /* Request to keep path relative.               */
      CCP_PROC_CYGDRIVE = 0x200 /* Request to return /proc/cygdrive path
                                   (only with CCP_*_TO_POSIX).                  */

`size` is the size of the buffer pointed to by `to` in bytes. If `size` is 0, `cygwin_conv_path` just returns the required buffer size in bytes. Otherwise, it returns 0 on success, or -1 on error and errno is set to one of the below values.

        EINVAL        what has an invalid value or from is NULL.
        EFAULT        from or to point into nirvana.
        ENAMETOOLONG  the resulting path is longer than 32K, or, in case
                      of what == CCP_POSIX_TO_WIN_A, longer than MAX_PATH.
        ENOSPC        size is less than required for the conversion.

### Example

#### Example use of cygwin_conv_path

    #include <sys/cygwin.h>

    /* Conversion from incoming Win32 path given as wchar_t *win32 to POSIX path.
       If incoming path is a relative path, stick to it.  First ask how big
       the output buffer has to be and allocate space dynamically. */
    ssize_t size;
    char *posix;
    size = cygwin_conv_path (CCP_WIN_W_TO_POSIX | CCP_RELATIVE, win32, NULL, 0);
    if (size < 0)
      perror ("cygwin_conv_path");
    else
      {
        posix = (char *) malloc (size);
        if (cygwin_conv_path (CCP_WIN_W_TO_POSIX | CCP_RELATIVE, win32,
                              posix, size))
          perror ("cygwin_conv_path");
      }

cygwin_conv_path_list
3
Cygwin API Reference

## cygwin_conv_path_list

    #include <sys/cygwin.h>

    ssize_t
    cygwin_conv_path_list
    cygwin_conv_path_t what
    const void * from
    void * to
    size_t size

### Description

This is the same as `cygwin_conv_path`, but the input is treated as a path list in $PATH or %PATH% notation.

If `what` is CCP_POSIX_TO_WIN_A or CCP_POSIX_TO_WIN_W, given a POSIX $PATH-style string (i.e. /foo:/bar) convert it to the equivalent Win32 %PATH%-style string (i.e. d:\;e:\bar).

If `what` is CCP_WIN_A_TO_POSIX or CCP_WIN_W_TO_POSIX, given a Win32 %PATH%-style string (i.e. d:\;e:\bar) convert it to the equivalent POSIX $PATH-style string (i.e. /foo:/bar).

`size` is the size of the buffer pointed to by `to` in bytes.

### See also

See also cygwin_conv_path

cygwin_create_path
3
Cygwin API Reference

## cygwin_create_path

    #include <sys/cygwin.h>

    void *
    cygwin_create_path
    cygwin_conv_path_t what
    const void * from

### Description

This is equivalent to the `cygwin_conv_path`, except that `cygwin_create_path` does not take a buffer pointer for the result of the conversion as input. Rather it allocates the buffer itself using `malloc`(3) and returns a pointer to this buffer. In case of error it returns NULL and sets errno to one of the values defined for `cygwin_conv_path`. Additionally errno can be set to the below value.

        ENOMEM        Insufficient memory was available.

When you don't need the returned buffer anymore, use `free`(3) to deallocate it.

### See also

See also cygwin_conv_path

cygwin_posix_path_list_p
3
Cygwin API Reference

## cygwin_posix_path_list_p

    #include <sys/cygwin.h>

    int
    cygwin_posix_path_list_p
    const char *path

### Description

This function tells you if the supplied `path` is a POSIX-style path (i.e. posix names, forward slashes, colon delimiters) or a Win32-style path (drive letters, reverse slashes, semicolon delimiters. The return value is true if the path is a POSIX path. Note that "_p" means "predicate", a lisp term meaning that the function tells you something about the parameter.

cygwin_split_path
3
Cygwin API Reference

## cygwin_split_path

    #include <sys/cygwin.h>

    void
    cygwin_split_path

    const char * path
    char * dir
    char * file

### Description

Split a path into the directory and the file portions. Both `dir` and `file` are expected to point to buffers of sufficient size.

### Example

#### Example use of cygwin_split_path

    char dir[200], file[100];
    cygwin_split_path("c:/foo/bar.c", dir, file);
    printf("dir=%s, file=%s\n", dir, file);