| PATHBUF(9) | Kernel Developer's Manual | PATHBUF(9) | 
pathbuf, pathbuf_create,
  pathbuf_assimilate,
  pathbuf_copyin,
  pathbuf_destroy —
#include <sys/namei.h>
struct pathbuf *
  
  pathbuf_create(const
    char *path);
struct pathbuf *
  
  pathbuf_assimilate(char
    *pnbuf);
int
  
  pathbuf_copyin(const
    char *userpath, struct
    pathbuf **ret);
void
  
  pathbuf_destroy(struct
    pathbuf *path);
pathbuf interface is used to carry around pathnames.
  This helps simplify the namei(9)
  interface. A pathbuf should be thought of as a path name string combined with
  whatever flags and metadata are needed to interpret it correctly. It is an
  abstract type; the internals are hidden within the
  namei(9) implementation.
The pathbuf_create() function allocates
    and initializes a new pathbuf containing a copy of the path string
    path, which should be a kernel pointer. The return
    value should be checked for being NULL in case the
    system is out of memory. Passing a path name larger than
    PATH_MAX will cause an assertion failure.
The pathbuf_copyin() function allocates
    and initializes a new pathbuf containing a path string copied from user
    space with copyinstr(9). It
    returns an error code.
The pathbuf_assimilate() function creates
    a pathbuf using the string buffer provided as pnbuf.
    This buffer must be of size PATH_MAX and must have
    been allocated with PNBUF_GET(). The buffer is
    “taken over” by the returned pathbuf and will be released when
    the pathbuf is destroyed. Note: to avoid confusion and pointer bugs,
    pathbuf_assimilate() should only be used where
    absolutely necessary; e.g. the NFS server code uses it to generate pathbufs
    from strings fetched from mbufs.
The pathbuf_destroy() function deallocates
    a pathbuf. Caution: because calling
    namei(9) loads pointers to
    memory belonging to the pathbuf into the nameidata structure, a pathbuf
    should only be destroyed by the namei() caller once
    all manipulations of the nameidata are complete.
Also note that calling namei() destroys
    the contents of the pathbuf. Do not reuse a pathbuf for a second call to
    namei().
pathbuf code is part of the name lookup code in
  sys/kern/vfs_lookup.c.
namei() has run. This produces an effect similar to
  realpath(3). The interface for
  doing this is, for the time being, intentionally undocumented and subject to
  change.
| November 30, 2010 | NetBSD 10.0 |