FBB::Stat - Determines File Characteristics
#include <bobcat/stat>
Linking option: -lbobcat
Stat is a wrapper around the stat(2) and
lstat(2) system functions. In particular, it offers features to test
directly for object characteristics offered by these two functions. To
determine whether an object could properly be constructed use the Stat
bool conversion operator. If this operator returns false then no
other member except for error should be used.
FBB
All constructors, members, operators and manipulators, mentioned in this
man-page, are defined in the namespace FBB.
Stat::Combine:
This enumeration defines the following values:
- o
- ALL: require all of the specified Mode or SpecialMode
values to match;
- o
- ANY: require any match of the specified Mode or
SpecialMode values (one match suffices);
Stat::Mode:
This enumeration defines the following values:
- o
- UR: the owner of the object has read permissions
- o
- UW: the owner of the object has write permissions
- o
- UX: the owner of the object has execute permissions
- o
- GR: the group to which the object belongs has read permissions
- o
- GW: the group to which the object belongs has write
permissions
- o
- GX: the group to which the object belongs has execute
permissions
- o
- OR: others have read permissions
- o
- OW: others have write permissions
- o
- OX: others have execute permissions
- o
- READ: equal to UR | GR | OR
- o
- WRITE: equal to UW | GW | OW
- o
- EXEC: equal to UX | GX | OX
- o
- RWX: all of the above.
Stat::SpecialMode:
This enumeration defines the following values:
- o
- SUID: set UID bit is up
- o
- SGID: set GID bit is up
- o
- SB: sticky bit is up
Stat::Type:
This enumeration, which is identical to the glob(3bobcat) Type
enumeration, defines the following values:
- o
- BLOCK_DEVICE (0060000): the object is a block device;
- o
- CHARACTER_DEVICE (0020000): the object is a character device;
- o
- DIRECTORY (0040000): the object is a directory;
- o
- FIFO (0010000): the object is a named pipe (a queue);
- o
- REGULAR_FILE (0100000): the object is a regular file;
- o
- SOCKET (0140000): the object is a socket;
- o
- SYMBOLIC_LINK (0120000): the object is a symbolic link;
- o
- ANY: any of the above types.
Stat::Lstat:
This enumeration has one value: LStat, which can be specified by
construtors and some members when the Stat object should distinguish
regular files and symbolic links (calling lstat(2)) instead of
considering symbolic links as regular files (using stat(2)).
Constructors and members that define Stat::Lstat parameters
call lstat(2), thus distinguishing symbolic links from regular files,
while constructors and members that do not define Stat::Lstat
parameters use stat(2).
The return values of the members statStruct and type
and typeStr (see below) only distinguish symbolic links from regular
files when the Stat::LStat argument has been used.
The constructors and member functions listed below for which
[Stat::Lstat,] is specified as first parameter may optionally specify
the Stat::LStat argument.
- o
- Stat():
The default constructor, creating an empty Stat object. It’s
mainly used as default object when defining, e.g., vectors of Stat
objects. As it doesn’t refer to an existing file system entry its
operator bool returns false;
- o
- Stat([Stat::Lstat,] std::string const &fname):
Initializes a Stat with a given object name;
- o
- Stat([Stat::Lstat,] std::string const &fname, std::string const
&searchPath):
Initializes a Stat with a given object name, where the object is
searched in the searchPath directories, which is a colon-separated
string of directory names. The filenames are constructed by appending
fname to each of the elements of searchPath until an
existing object is found. This object is then used. If fname is an
absolute path, searchPath is ignored.
Copy and move constructors (and assignment operators) are
available.
- o
- operator bool() const:
This operator returns true if the Stat object holds
information about an existing object. Otherwise false is returned.
When false is returned other members, except for the assignment
operators, the error member, and the set members should not
be used.
- o
- bool access(FBB::User const &user, size_t spec, bool useEffective
= true) const:
Returns true if user has the permissions as specified at
spec (of which only the defined Mode bits are interpreted).
If a combination of read, write and/or execute permissions are specified,
then at least one of the read permissions, one of the write permissions
and one of the execute permissions must be granted or the function returns
false. E.g, when specifying access(user, UW | UR |
GR) then the user must have write permissions, but either the
user or the user’s group must have read permissions. If multiple
read, multiple write or multiple execute permissions are specified (like
UR | GR) then this member returns true if at least one of
the requested read, write, or execute permissions are granted for
user.
- o
- size_t blockSize() const:
Returns the blocksize (st_blksize) for filesystem I/O
- o
- size_t device() const:
Returns the device id (st_dev).
- o
- size_t deviceType() const:
Returns the device type number, but only if the object type is DEVICE
(st_rdev).
- o
- size_t error() const:
Returns the error number associated with an error, in cases where
operator bool() returns false. A returned value of 0
indicates `no errors’. To obtain a verbal transcription of returned
error numbers the Exception::errnodescr manipulator (cf.
exception(3bobcat)) can be used.
- o
- bool isType(Stat::Type probe):
Returns true if the object has the probed type otherwise false
is returned.
- o
- size_t inode() const:
Returns the inode number (st_ino).
- o
- size_t gid() const:
Returns the group ID of the object’s owner (st_gid).
- o
- FBB::DateTime lastAccess() const:
Returns an FBB::DateTime object holding information about the
object’s time of last access (st_atime) (using UTC).
- o
- FBB::DateTime lastChange() const:
Returns an FBB::DateTime object holding information about the
object’s time of last status change (st_ctime) (using
UTC).
- o
- FBB::DateTime lastModification() const:
Returns an FBB::DateTime object holding information about the
object’s last modification time (st_mtime) (using UTC).
- o
- size_t mode() const:
Returns the object’s raw, uninterpreted mode (st_mode &
RWX). Note that this value is usually displayed (and is processed most
easily) as an octal value.
- o
- bool mode(size_t mode, Combine combine = ALL):
Returns true if the object has the indicated mode. Multiple modes may be
set, which can be combined by the logical bitor operator. By
default, if multiple modes are specified, the resulting pattern must
exactly represent the object’s mode for the member function to
return true. An optional argument ANY may be specified if
the function should return true if at least one specified mode matches the
object’s actual mode. An Exception exception is thrown if
the specified mode contains other values than the defined
Mode or SpecialMode values.
- o
- std::string modeStr() const:
Returns the standard string-representation of the object’s mode
(e.g., rw-r--r--). Special modes (e.g., suid) are indicated by
s instead of x when the object is user and/or group
executable and by S if the object has the special mode bit(s) set,
but is not executable. For the `other’ executable mode flag
t is used (`sticky’ bit) and T if the object is not
`other’ executable.
- o
- std::string const &name() const:
Returns the object’s name as specified in the constructor or
set() member function.
- o
- size_t nBlocks() const:
Returns the object’s number of allocated blocks
(st_blocks).
- o
- size_t nLinks() const:
Returns the object’s number of hard links (st_nlink).
- o
- std::string path() const:
Returns the object’s full pathname. If the full pathname could not be
determined, an empty string is returned.
- o
- bool set([Stat::Lstat,] std::string const &name):
Redefine the Stat object to represent the information about the
indicated object name.
- o
- bool set([Stat::Lstat,] std::string const &name, std::string
const &pathlist):
Redefine the Stat object to represent the information about the
indicated object name, where the object is searched in the pathlist
directories, which is a colon-separated string of directory names. The
object names are constructed by appending fname to each of the
elements of searchPath until an existing object is found. This
object is then used. If fname is an absolute path,
searchPath is ignored.
- o
- off_t size() const:
Returns the object’s size in number of bytes (st_size).
- o
- bool specialMode(size_t special, Combine combine = ALL):
Returns true if the object has the indicated special modes. Multiple special
modes may be specified, which can be combined by the logical bitor
operator. By default, if multiple modes are specified, the resulting
pattern must exactly represent the object’s mode for the member
function to return true. An optional argument ANY may be
specified if the function should return true if at least one specified
mode matches the object’s actual mode. The non-special modes are
ignored but a Exception exception is thrown if special
contains other values than those defined by the SpecialMode
enum.
- o
- Stat::stat const &statStruct() const:
Returns a reference to the object’s stat struct.
- o
- Stat::Type type() const:
Returns the Stat::Type value of the object.
- o
- std::string typeStr() const:
Returns a textual representation of the object’s type as returned by
the Stat::type() member function.
- o
- size_t uid() const:
Returns the user ID of the object’s owner (st_uid).
/*
driver.cc
*/
#include <iostream>
#include <string>
#include "../stat"
#include <bobcat/datetime>
using namespace std;
using namespace FBB;
int main(int argc, char **argv)
{
if (argc == 1)
{
cout << "Usage: driver [-l] object [colon-separated searchpath]\n";
return 1;
}
bool lstat = "-l"s == argv[1];
if (lstat)
{
++argv;
--argc;
}
Stat st;
if (argc == 2)
{
if (lstat)
st.set(Stat::LStat, argv[1]);
else
st.set(argv[1]);
}
else if (argc == 3)
{
if (lstat)
st.set(Stat::LStat, argv[1], argv[2]);
else
st.set(argv[1], argv[2]);
}
if (!st)
{
cout << "Can’t stat " << argv[1] << ", errno = " << st.error() << endl;
return 1;
}
cout << st.name() << ": access: " << st.lastAccess() << "\n" <<
st.name() << ": change: " << st.lastChange() << "\n" <<
st.name() << ": modif: " << st.lastModification() << "\n"
"Mode: " << oct << st.mode() << " (" << st.modeStr() << ")\n"
"Type: " << st.type() << " (" << st.typeStr() << ")\n"
"Full path: " << st.path() << endl;
}
bobcat/stat - defines the class interface
- o
- https://fbb-git.gitlab.io/bobcat/: gitlab project page;
- o
- bobcat_6.02.02-x.dsc: detached signature;
- o
- bobcat_6.02.02-x.tar.gz: source archive;
- o
- bobcat_6.02.02-x_i386.changes: change log;
- o
- libbobcat1_6.02.02-x_*.deb: debian package containing the
libraries;
- o
- libbobcat1-dev_6.02.02-x_*.deb: debian package containing the
libraries, headers and manual pages;
Bobcat is an acronym of `Brokken’s Own Base Classes And
Templates’.
This is free software, distributed under the terms of the GNU
General Public License (GPL).
Frank B. Brokken (f.b.brokken@rug.nl).