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// Copyright (c) 1999-2000 David Muse
// See the COPYING file for more information.
#ifndef PERMISSIONS_H
#define PERMISSIONS_H
// Permissions are access priveleges. Files, directories, semaphores and
// shared memory segments all have permissions associated with them.
//
// There are 3 types of permissions: read, write and execute.
//
// These permissions can be granted to:
// 1. The user that owns the object.
// 2. Other users in the group of the user that owns the object.
// 3. All other users.
//
// The execute permission has 2 modifications which can be applied to it:
// 1. Set user id - the program will run as the user that owns
// it instead of as the user that ran it
// 1. Set group id - the program will run as the group that owns
// it instead of as the group of the user that ran it
//
// The "sticky bit" may also be set. When set, the file is saved in the
// system's swap space. As a side-effect, it cannot be deleted by a user other
// than the one that created it.
#include <sys/types.h>
class permissions {
public:
static int setFilePermissions(char *filename,
mode_t perms);
// set the permissions on "filename" to "perms"
static int setFilePermissions(int filehandle,
mode_t perms);
// set the permissions on the file associated
// with "filehandle" to "perms"
static mode_t evalPermString(char *permstring);
// Return a permission defined in "permstring".
//
// "permstring" should be the same format as
// displayed by the "ls -l" command.
//
// The first 3 characters set permissions for
// the owner.
// The next 3 characters set permissions for
// the group.
// The next 3 characters set permissions for
// all others.
//
// For example:
// rwxr-xr-x : read/execute for everyone
// and write for the owner
// rw-rw-r-- : read for everyone and
// write for the owner and
// owner's group
// rw-r--r-- : read for everyone and
// write for the owner
// rwsr-sr-x : read/execute for everyone,
// write for the owner and
// run as the user/group
// that owns the file
// rw-rw-rwt : read/write for everyone,
// and save the file in
// swap space
// The following methods can be or'ed together to define
// a permission. For example:
//
// mode_t perm=(ownerReadWriteExecute() |
// groupReadExecute() |
// othersReadExecute())
//
// sets perm equal to rwxr-xr-x permissions
static mode_t everyoneReadWrite();
// returns rw-rw-rw- (666) permissions
static mode_t everyoneReadWriteExecute();
// returns rwxrwxrwx (777) permissions
static mode_t ownerRead();
// returns r-------- (400) permissions
static mode_t ownerWrite();
// returns -w------- (200) permissions
static mode_t ownerExecute();
// returns --x------ (100) permissions
static mode_t ownerReadWrite();
// returns rw------- (600) permissions
static mode_t ownerReadExecute();
// returns r-x------ (500) permissions
static mode_t ownerReadWriteExecute();
// returns rwx------ (700) permissions
static mode_t groupRead();
// returns ---r----- (040) permissions
static mode_t groupWrite();
// returns ----w---- (020) permissions
static mode_t groupExecute();
// returns -----x--- (010) permissions
static mode_t groupReadWrite();
// returns ---rw---- (060) permissions
static mode_t groupReadExecute();
// returns ---r-x--- (050) permissions
static mode_t groupReadWriteExecute();
// returns ---rwx--- (070) permissions
static mode_t othersRead();
// returns ------r-- (004) permissions
static mode_t othersWrite();
// returns -------w- (002) permissions
static mode_t othersExecute();
// returns --------x (001) permissions
static mode_t othersReadWrite();
// returns ------rw- (006) permissions
static mode_t othersReadExecute();
// returns ------r-x (005) permissions
static mode_t othersReadWriteExecute();
// returns ------rwx (007) permissions
static mode_t saveInSwapSpace();
// returns --------t permissions
static mode_t setUserId();
// returns --s------ (u+s) permissions
static mode_t setGroupId();
// returns -----s--- (g+s) permissions
};
#endif
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