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/*----------------------------------------------------------------------------*/
/*lib.h*/
/*----------------------------------------------------------------------------*/
/*Basic routines for filesystem manipulations*/
/*----------------------------------------------------------------------------*/
/*Based on the code of unionfs translator.*/
/*----------------------------------------------------------------------------*/
/*Copyright (C) 2001, 2002, 2005 Free Software Foundation, Inc.
Written by Sergiu Ivanov <unlimitedscolobb@gmail.com>.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or * (at your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
USA.*/
/*----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
#define _GNU_SOURCE 1
/*----------------------------------------------------------------------------*/
#include <sys/mman.h>
/*----------------------------------------------------------------------------*/
#include "lib.h"
#include "debug.h"
/*----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
/*--------Functions-----------------------------------------------------------*/
/*Fetches directory entries for `dir`*/
error_t
dir_entries_get
(
file_t dir,
char ** dirent_data, /*the list of directory entries as returned
by dir_readdir*/
size_t * dirent_data_size, /*the size of `dirent_data`*/
struct dirent *** dirent_list /*the array of pointers to beginnings of
dirents in dirent_data*/
)
{
error_t err = 0;
/*The data (array of dirents(?)) returned by dir_readdir*/
char * data;
/*The size of `data`*/
size_t data_size;
/*The number of entries in `data`*/
int entries_num;
/*Try to read the contents of the specified directory*/
err = dir_readdir(dir, &data, &data_size, 0, -1, 0, &entries_num);
if(err)
return err;
/*Create a new list of dirents*/
struct dirent ** list;
/*Allocate the memory for the list of dirents and for the
finalizing element*/
list = malloc(sizeof(struct dirent *) * (entries_num + 1));
/*If memory allocation has failed*/
if(!list)
{
/*free the result of dir_readdir*/
munmap(data, data_size);
/*return the corresponding error*/
return ENOMEM;
}
/*The current directory entry*/
struct dirent * dp;
int i;
/*Go through every element of the list of dirents*/
for
(
i = 0, dp = (struct dirent *)data;
i < entries_num;
++i, dp = (struct dirent *)((char *)dp + dp->d_reclen))
/*copy the current value into the list*/
*(list + i) = dp;
/*Nullify the last element of the list*/
*(list + i) = NULL;
/*Copy the required values in the parameters*/
*dirent_data = data;
*dirent_data_size = data_size;
*dirent_list = list;
/*Return success*/
return err;
}/*dir_entries_get*/
/*----------------------------------------------------------------------------*/
/*Lookup `name` under `dir` (or cwd, if `dir` is invalid)*/
error_t
file_lookup
(
file_t dir,
char * name,
int flags0, /*try to open with these flags first*/
int flags1, /*try to open with these flags, if `flags0` fail*/
int mode, /*if the file is to be created, create it with this mode*/
file_t * port, /*store the port to the looked up file here*/
io_statbuf_t * stat /*store the stat information here*/
)
{
error_t err = 0;
/*The port to the looked up file*/
file_t p;
/*The stat information about the looked up file*/
io_statbuf_t s;
/*Performs a lookup under 'dir' or in cwd, if `dir` is invalid*/
file_t
do_file_lookup
(
file_t dir,
char * name, /*lookup this file*/
int flags, /*lookup the file with these flags*/
int mode /*if a new file is to be created, create it with this mode*/
)
{
/*The result of lookup*/
file_t p;
/*If `dir` is a valid port*/
if(dir != MACH_PORT_NULL)
/*try to lookup `name` under `dir`*/
p = file_name_lookup_under(dir, name, flags, mode);
else
/*lookup `name` under current cwd*/
p = file_name_lookup(name, flags, mode);
/*Return the result of the lookup*/
return p;
}/*do_file_lookup*/
/*Lookup `name` under the suggested `dir`*/
p = do_file_lookup(dir, name, flags0, mode);
/*If the lookup failed*/
if(p == MACH_PORT_NULL)
/*try to lookup for `name` using alternative flags `flags1`*/
p = do_file_lookup(dir, name, flags1, mode);
/*If the port is valid*/
if(p != MACH_PORT_NULL)
{
/*If stat information is required*/
if(stat)
{
/*obtain stat information for `p`*/
err = io_stat(p, &s);
if(err)
PORT_DEALLOC(p);
}
}
else
/*copy `errno` into `err`*/
err = errno;
/*If no errors have happened during lookup*/
if(!err)
{
/*copy the resulting port into *`port`*/
*port = p;
/*fill in the receiver for stat information, if requried*/
if(stat)
*stat = s;
}
/*Return the result of performing operations*/
return err;
}/*file_lookup*/
/*----------------------------------------------------------------------------*/
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