oracular (3) stat.3bobcat.gz

Provided by: libbobcat-dev_6.06.01-1_amd64 bug

NAME

       FBB::Stat - Determines File Characteristics

SYNOPSIS

       #include <bobcat/stat>
       Linking option: -lbobcat

DESCRIPTION

       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.

NAMESPACE

       FBB
       All constructors, members, operators and manipulators, mentioned in this man-page,  are  defined  in  the
       namespace FBB.

INHERITS FROM

       -

ENUMERATIONS

       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.

CONSTRUCTORS

       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.

OVERLOADED OPERATORS

       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.

MEMBER FUNCTIONS

       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).

EXAMPLE

       /*
                                     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;
       }

FILES

       bobcat/stat - defines the class interface

SEE ALSO

       bobcat(7), glob(3bobcat), stat(2), lstat(2)

BUGS

       None Reported.

BOBCAT PROJECT FILES

       o      https://fbb-git.gitlab.io/bobcat/: gitlab project page;

       o      bobcat_6.06.01-x.dsc: detached signature;

       o      bobcat_6.06.01-x.tar.gz: source archive;

       o      bobcat_6.06.01-x_i386.changes: change log;

       o      libbobcat1_6.06.01-x_*.deb: debian package containing the libraries;

       o      libbobcat1-dev_6.06.01-x_*.deb: debian package containing the libraries, headers and manual pages;

BOBCAT

       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).

AUTHOR

       Frank B. Brokken (f.b.brokken@rug.nl).