OksSystem::User Class Reference

User. More...

#include <User.hpp>

Collaboration diagram for OksSystem::User:

Public Member Functions
	User () throw ()
	constructor for current user
	User (uid_t user_id) throw ()
	constructor from uid
	User (const std::string &name)
	constructor from name
	User (const User &other) throw ()
	copy constructor
	operator uid_t () const throw ()
	cast to user id
	operator std::string () const
	cast to string
	operator const char * () const
	cast to c-string
uid_t	identity () const throw ()
	user-id
const std::string &	name () const
	username
const std::string &	name_safe () const throw ()
	username - no exception
const std::string &	home () const
	home directory name
const std::string &	real_name () const
	real name
void	setuid () const
	tries to set the uid of current process

Static Public Attributes
static const User	ROOT
	constant for root user

Protected Member Functions
void	resolve () const
	resolve information from user-id
void	resolve_safe () const throw ()
	resolve without throwing exceptions

Protected Attributes
uid_t	m_user_id
	the actual user id
std::string	m_user_name
	cached user name
std::string	m_user_home
	cached user home directory
std::string	m_user_real_name
	cached real user name

Detailed Description

User.

This class represents an user

Author

Matthias Wiesmann

Version

1.0

Definition at line 30 of file User.hpp.

Constructor & Destructor Documentation

User() [1/4]

OksSystem::User::User	(		)
throw	(	)

constructor for current user

Definition at line 27 of file User.cpp.

{
  m_user_id = ::getuid();
} // User

User() [2/4]

OksSystem::User::User	(	uid_t	user_id	)
throw	(	)

constructor from uid

Definition at line 32 of file User.cpp.

{
  m_user_id = user_id;
} // User

User() [3/4]

OksSystem::User::User

(

const std::string &

name

)

constructor from name

Definition at line 37 of file User.cpp.

{
 
  errno = 0;
  long bufSize = ::sysconf(_SC_GETPW_R_SIZE_MAX);
 
  if (bufSize == -1) {
    if (errno == 0) {
      bufSize = 1024;
    } else {
      std::string message = "with argument _SC_GETPW_R_SIZE_MAX while getting info about user " + s_name;
      throw OksSystem::OksSystemCallIssue(ERS_HERE, errno, "sysconf", message.c_str());
    }
  }
 
  struct passwd pwd;
  struct passwd* result;
  char* buf = new char[bufSize];
  errno = 0;
  int res = ::getpwnam_r(s_name.c_str(), &pwd, buf, bufSize, &result);
  if (res == 0) {
    if (result != 0) {
      m_user_id = result->pw_uid;
    } else {
      delete[] buf;
      std::string eMsg = "User " + s_name + " not found";
      throw OksSystem::OksSystemCallIssue(ERS_HERE, errno, "getpwnam_r", eMsg.c_str());
    }
  } else {
    delete[] buf;
    std::string message = "while getting info about user " + s_name;
    throw OksSystem::OksSystemCallIssue(ERS_HERE, res, "getpwnam_r", message.c_str());
  }
  delete[] buf;
 
  m_user_name = s_name;
} // User

User() [4/4]

OksSystem::User::User	(	const User &	other	)
throw	(	)

copy constructor

Definition at line 75 of file User.cpp.

{
  m_user_id = other.m_user_id;
  m_user_name = other.m_user_name;
} // User

Member Function Documentation

home()

const std::string & OksSystem::User::home

(

)

const

home directory name

Gets the home directory of the user

Returns

path to home directory

Definition at line 241 of file User.cpp.

{
  if (m_user_home.empty()) {
    resolve();
  }
  return m_user_home;
} // home

identity()

uid_t OksSystem::User::identity	(		)	const
throw	(	)

user-id

Returns the user_id for user

Returns

user-id

Definition at line 110 of file User.cpp.

{
  return m_user_id;
} // identity

name()

const std::string & OksSystem::User::name

(

)

const

username

Gets the (short) name of the user

Returns

the name of user

Definition at line 215 of file User.cpp.

{
  if (m_user_name.empty()) {
    resolve();
  }
  return m_user_name;
} // name

name_safe()

const std::string & OksSystem::User::name_safe	(		)	const
throw	(	)

username - no exception

Gets the (short) name of the user - no error is thrown in case of problem

Returns

the name of user

Definition at line 228 of file User.cpp.

{
  if (m_user_name.empty()) {
    resolve_safe();
  }
  return m_user_name;
} // name

operator const char *()

OksSystem::User::operator const char *

(

)

const

cast to c-string

Definition at line 94 of file User.cpp.

{
  if (m_user_name.empty()) {
    resolve();
  }
  return m_user_name.c_str();
} // char*

operator std::string()

OksSystem::User::operator std::string

(

)

const

cast to string

Definition at line 89 of file User.cpp.

{
  return name();
} // string

operator uid_t()

OksSystem::User::operator uid_t	(		)	const
throw	(	)

cast to user id

Definition at line 84 of file User.cpp.

{
  return m_user_id;
} // uid_t

real_name()

const std::string & OksSystem::User::real_name

(

)

const

real name

Gets the 'real name' of the user

Returns

real name

Definition at line 254 of file User.cpp.

{
  if (m_user_real_name.empty()) {
    resolve();
  }
  return m_user_real_name;
} // real_name

resolve()

void OksSystem::User::resolve ( ) const

protected

resolve information from user-id

This method is responsible for filling in the mutable fields of the class when needed, this is done by calling the getpwuid function, all fields of the object are then filled in.

Exceptions

OksSystem::OksSystemCallIssue

if the user information cannot be found

Definition at line 122 of file User.cpp.

{
 
  errno = 0;
  long bufSize = ::sysconf(_SC_GETPW_R_SIZE_MAX);
 
  if (bufSize == -1) {
    if (errno == 0) {
      bufSize = 1024;
    } else {
      std::ostringstream message;
      message << "with argument _SC_GETPW_R_SIZE_MAX while getting info about user with id " << m_user_id;
      throw OksSystem::OksSystemCallIssue(ERS_HERE, errno, "sysconf", message.str().c_str());
    }
  }
 
  struct passwd pwd;
  struct passwd* result;
  char* buf = new char[bufSize];
  errno = 0;
  int res = ::getpwuid_r(m_user_id, &pwd, buf, bufSize, &result);
  if (res == 0) {
    if (result != 0) {
      m_user_name = std::string(result->pw_name);
      m_user_home = std::string(result->pw_dir);
      m_user_real_name = std::string(result->pw_gecos);
    } else {
      delete[] buf;
      std::ostringstream eMsg;
      eMsg << "User " << m_user_id << " not found";
      throw OksSystem::OksSystemCallIssue(ERS_HERE, errno, "getpwuid_r", eMsg.str().c_str());
    }
  } else {
    delete[] buf;
    std::ostringstream message;
    message << "while getting info about user with id " << m_user_id;
    throw OksSystem::OksSystemCallIssue(ERS_HERE, res, "getpwnam_r", message.str().c_str());
  }
  delete[] buf;
 
} //

resolve_safe()

void OksSystem::User::resolve_safe ( ) const throw (  )

protected

resolve without throwing exceptions

This method is the same as resolve() but does not throw exceptions. Instead the method silently fails

See also

OksSystem::User::resolve()

Definition at line 170 of file User.cpp.

{
 
  errno = 0;
  long bufSize = ::sysconf(_SC_GETPW_R_SIZE_MAX);
 
  if (bufSize == -1) {
    if (errno == 0) {
      bufSize = 1024;
    } else {
      m_user_name = "unknown";
      m_user_home = "unknown";
      m_user_real_name = "unknown";
      return;
    }
  }
 
  struct passwd pwd;
  struct passwd* result;
  char* buf = new char[bufSize];
  int res = ::getpwuid_r(m_user_id, &pwd, buf, bufSize, &result);
  if (res == 0) {
    if (result != 0) {
      m_user_name = std::string(result->pw_name);
      m_user_home = std::string(result->pw_dir);
      m_user_real_name = std::string(result->pw_gecos);
    } else {
      m_user_name = "unknown";
      m_user_home = "unknown";
      m_user_real_name = "unknown";
    }
  } else {
    m_user_name = "unknown";
    m_user_home = "unknown";
    m_user_real_name = "unknown";
  }
  delete[] buf;
 
} // resolve_safe

setuid()

void OksSystem::User::setuid

(

)

const

tries to set the uid of current process

Sets the user-identity of the current process to this user. This method will only succeed if the current user has sufficient privileges to changed uids (typically because the current user is root).

Definition at line 268 of file User.cpp.

{
  const int status = ::setuid(m_user_id);
  if (status < 0) {
    std::ostringstream message;
    message << "while setting the effective user ID to " << m_user_id << "(" << this->name_safe() << ")";
    throw OksSystem::OksSystemCallIssue(ERS_HERE, errno, "setuid", message.str().c_str());
  }
} // setuid

Member Data Documentation

m_user_home

std::string OksSystem::User::m_user_home

mutableprotected

cached user home directory

Definition at line 36 of file User.hpp.

m_user_id

uid_t OksSystem::User::m_user_id

protected

the actual user id

Definition at line 34 of file User.hpp.

m_user_name

std::string OksSystem::User::m_user_name

mutableprotected

cached user name

Definition at line 35 of file User.hpp.

m_user_real_name

std::string OksSystem::User::m_user_real_name

mutableprotected

cached real user name

Definition at line 37 of file User.hpp.

ROOT

const OksSystem::User OksSystem::User::ROOT

static

constant for root user

Definition at line 41 of file User.hpp.

---

The documentation for this class was generated from the following files:

• /github/workspace/dunedaq/sourcecode/okssystem/include/okssystem/User.hpp
• /github/workspace/dunedaq/sourcecode/okssystem/src/User.cpp