proc_dir_entry, proc_register, proc_register_dynamic,
     proc_unregister - register entries in the /proc filesystem.


     #include <linux/proc_fs.h>

struct proc_dir_entry * child);

     int proc_register(struct proc_dir_entry * parent,

     int proc_unregister(struct proc_dir_entry * parent, int

struct proc_dir_entry * child);

     int proc_register_dynamic(struct proc_dir_entry * parent,


     The proc_register functions add file or directory entries to
     the  /proc  file system.  They associate processing routines
     with  each  node  of  the   /proc   tree.    The   structure
     proc_dir_entry is defined as

     struct proc_dir_entry {
             unsigned short low_ino;
             unsigned short namelen;
             const char *name;
             mode_t mode;
             nlink_t nlink;
             uid_t uid;
             gid_t gid;
             unsigned long size;
             struct inode_operations * ops;
             int (*get_info)(char *buffer, char **start,
                     off_t offset, int length, int unused);
             void (*fill_inode)(struct inode *);
             struct proc_dir_entry *next, *parent, *subdir;
             void *data;

     low_ino The inode  number  of  this  directory  entry.   For
             proc_register  this   number should be unique within
             the  /proc  filesystem,  values   are   defined   in
             <linux/proc_fs.h>.   For  proc_register_dynamic  the
             inode number is dynamically assigned.

     namelen The length of the name, excluding the trailing null.

     name    The name of this node.

     mode    The  node's  type  and  permissions.    Drawn   from

     nlink   Number of links to the node.   Initialise  to  2  if
             mode includes S_IFDIR, 1 otherwise.

     uid     The uid that owns the node, normally 0.

     gid     The gid that owns the node. normally 0.

     size    Sets the size of the node, the value will appear  as
             the  inode size in listings and be returned by stat.
             Unless you really need a size, set this to zero.

     ops     Defines the set of inode operations to  perform  for
             your   /proc   node.   For  a  directory  node,  use
             &proc_dir_inode_operations unless you  have  special
             requirements.   For  a leaf node, set to NULL unless
             you have special requirements.

             If defined, this proc is called  when  the  node  is
             read.  Should be NULL for directory nodes.  NOTE: If
             you need to return large amounts of data,  the  proc
             must return the data in chunks and reposition itself
             on the next call, using the  offset  variable.   See
             ip_masq_procinfo for example code with large output.

             Dynamically fill in the inode characteristics during
             directory operations.  Not normally required and set
             to NULL.  See proc_pid_fill_inode for example code.

     next, parent, subdir
             Maintained by  /proc  routines.   Initial  value  is
             irrelevant, set to NULL.

     data    An opaque pointer which can be used by proc handlers
             to pass local data around.  Set to whatever you like
             when calling  proc_register,  normally  NULL.   This
             pointer  is copied into the inode u.ip_generic field
             (by proc_get_inode) so it is available to  any  proc
             routines that are passed an inode.

     proc_register adds the child as a node under the parent.

     proc_register_dynamic dynamically assigns  an  inode  number
     then adds the child as a node under the parent.

     proc_unregister scans the inode list under  the  parent  for
     the specified inode number and removes the matching entry.


     proc_register always returns 0.

     proc_register_dynamic returns 0 for success  or  -EAGAIN  if
     there are no free dynamic inode numbers.

     proc_unregister returns 0 for success or -EINVAL if the node
     was not found.


     proc_net_register(9), proc_net_unregister(9),


     Keith Owens <>


     The uniqueness  of  /proc  inode  numbers  is  assumed,  not
     enforced.   It  is  possible  to add two nodes with the same
     inode number.