JSYSTEM Namespace Reference

Auxiliary classes and methods for operating system calls. More...

Classes
struct	JDateAndTime
	Auxililary class to get date and time. More...
struct	JGlob
	Auxiliary class to list files. More...
class	JKeypress
	Enable unbuffered terminal input. More...
class	JProcess
	Streaming of input and output from Linux command. More...
class	JShell
	The JShell clas can be used to interact with the shell via I/O streams. More...
struct	JStat
	Auxiliary class for file status. More...
struct	JSysinfo
	Auxiliary class for system information. More...
struct	ls
	Auxiliary data structure to list files in directory. More...
struct	JLocalTime
	Auxililary class to local get time in micro seconds. More...
struct	JUTSName
	Auxiliary class for operating system information. More...

Typedefs
typedef long long int	localtime_t
	Type definition of local time. More...

Enumerations
enum	JDateAndTimeFormat { HUMAN_READABLE = 0, ISO8601 = 1 }
	Date and time formats. More...

Functions
const char *	getDate (const JDateAndTimeFormat option=ISO8601)
	Get ASCII formatted date. More...
const char *	getTime (const JDateAndTimeFormat option=ISO8601)
	Get ASCII formatted time. More...
std::string	getHostname ()
	Get host name. More...
std::string	getHostname (const int ip)
	Get host name. More...
int	getIPnumber (const std::string &host_name)
	Get IP number. More...
int	getIPnumber ()
	Get IP number. More...
std::string	getIPaddress (const int ip)
	Get IP address (decimal-dot notation). More...
std::string	getIPaddress ()
	Get IP address (decimal-dot notation). More...
unsigned short	getSubaddress (const int ip)
	Get host identifier within network. More...
unsigned short	getSubaddress ()
	Get host identifier within network. More...
std::vector< std::string >	getListOfIPaddresses ()
	Get list of IP address (decimal-dot notation). More...
float	getMemoryUsage (JShell &shell, const pid_t pid)
	Get memory usage in percent of given process identifier. More...
float	getMemoryUsage (JShell &shell)
	Get memory usage in percent of this process. More...
float	getMemoryUsage ()
	Get memory usage in percent of this process. More...
float	getCpuUsage (JShell &shell, const pid_t pid)
	Get cpu usage in percent of given process identifier. More...
float	getCpuUsage (JShell &shell)
	Get cpu usage in percent of this process. More...
float	getCpuUsage ()
	Get cpu usage in percent of this process. More...
pid_t	getPID (JShell &shell, const char *process)
	Get process identifier. More...
pid_t	getPID (const char *process)
	Get process identifier. More...
pid_t	getParentID (JShell &shell, pid_t pid)
	Get parent process identifier. More...
pid_t	getParentID (const pid_t pid)
	Get parent process identifier. More...
std::string	getShell (JShell &shell)
	Get shell name. More...
std::string	getShell ()
	Get shell name of this process. More...
unsigned long long int	getRAM ()
	Get RAM of this CPU. More...
const std::string	which (JShell &shell, const char *process)
	Get process path. More...
const std::string	which (const char *process)
	Get process path. More...
void	gprint (const std::string &message)
	Print method. More...
int	gexit (int status, const std::string &message="")
	Exit method. More...
void	set_variable (const std::string &name, const std::string &value)
	Set environment variable. More...

Variables
static JDateAndTime	getDateAndTime
	Function object to get ASCII formatted date and time. More...
static JGlob	getFilenames
	Function object to get list of files for given pattern. More...
static const JCompareEndian	compareEndian
	Function object operator. More...
static JStat	getFileStatus
	Function object for file status. More...
static const char *const	SH = "sh"
	Shell names. More...
static const char *const	ZSH = "zsh"
static const char *const	KSH = "ksh"
static const char *const	BASH = "bash"
static const char *const	CSH = "csh"
static const char *const	TCSH = "tcsh"
static const std::string	SPECIAL_CHARACTERS = "\"' <>[](){};$#"
static const JLocalTime	getLocalTime
	Function object to get local time in micro seconds. More...

Detailed Description

Auxiliary classes and methods for operating system calls.

Author

mdejong

Typedef Documentation

typedef long long int JSYSTEM::localtime_t

Type definition of local time.

Definition at line 21 of file JSystem/JTime.hh.

Enumeration Type Documentation

enum JSYSTEM::JDateAndTimeFormat

Date and time formats.

Enumerator
HUMAN_READABLE	Human readable format (Www Mmm dd hh:mm:ss yyyy)
ISO8601	ISO-8601 standard.

Definition at line 23 of file JSystem/JDate.hh.

                          {
    HUMAN_READABLE = 0,        //!< Human readable format (Www Mmm dd hh:mm:ss yyyy)
    ISO8601        = 1         //!< ISO-8601 standard 
  };

Function Documentation

const char* JSYSTEM::getDate ( const JDateAndTimeFormat  option = ISO8601 )

inline

Get ASCII formatted date.

Parameters

option

formatting option

Returns

date

Definition at line 35 of file JSystem/JDate.hh.

  {
    static time_t    ts;
    static const int        MAX_SIZE = 256;
    static char      buffer[MAX_SIZE];

    time(&ts);

    switch (option) {
      
    case HUMAN_READABLE:
      strftime(buffer, MAX_SIZE, "%x", localtime(&ts));
      break;
      
    case ISO8601:
      strftime(buffer, MAX_SIZE, "%F", localtime(&ts));
      break;
      
    default:
      THROW(JLANG::JValueOutOfRange, "JDate::getDate(): Invalid formatting option.");
    }
      
    return buffer;
  }

const char* JSYSTEM::getTime ( const JDateAndTimeFormat  option = ISO8601 )

inline

Get ASCII formatted time.

Parameters

option

formatting option

Returns

time

Definition at line 67 of file JSystem/JDate.hh.

  {
    static time_t    ts;
    static const int        MAX_SIZE = 256;
    static char      buffer[MAX_SIZE];

    time(&ts);

    switch (option) {
      
    case HUMAN_READABLE:
      strftime(buffer, MAX_SIZE, "%X %Z", localtime(&ts));
      break;

    case ISO8601:
      strftime(buffer, MAX_SIZE, "%T%z", localtime(&ts));
      break;

    default:
      THROW(JLANG::JValueOutOfRange, "JDate::getTime(): Invalid formatting option.");
    }
    
    return buffer;
  }

std::string JSYSTEM::getHostname ( )

inline

Get host name.

Note that to obtain a host name including the domain name, JSYSTEM::getHostname(JSYSTEM::getIPnumber()) should be used.

Returns

host name

Definition at line 77 of file JNetwork.hh.

  {
    const size_t MAXIMUM_LENGTH = 256;
    char  buffer[MAXIMUM_LENGTH];

    if (gethostname(buffer, MAXIMUM_LENGTH) == 0)
      return std::string(buffer);
    else
      throw JSystemException("Unknown host name.");
  }

std::string JSYSTEM::getHostname ( const int  ip )

inline

Get host name.

Parameters

ip

IP number

Returns

host name

Definition at line 96 of file JNetwork.hh.

  {
    in_addr buffer;

    buffer.s_addr = ip;

    hostent* p = gethostbyaddr(&buffer, sizeof(in_addr), AF_INET);

    if (p != NULL)
      return std::string(p->h_name);
    else
      throw JSystemException("Unknown IP address.");
  }

int JSYSTEM::getIPnumber ( const std::string &  host_name )

inline

Get IP number.

Parameters

host_name

host name

Returns

IP number

Definition at line 117 of file JNetwork.hh.

  {
    int ip = -1;

    std::string buffer = host_name;

    if (buffer == "" || buffer == "localhost") {
      buffer = getHostname();
    }

    const hostent* hp = gethostbyname(buffer.c_str());

    if (hp != NULL) {
      memcpy((char *) &ip, hp->h_addr, sizeof(int));
    }

    return ip;
  }

int JSYSTEM::getIPnumber ( )

inline

Get IP number.

Returns

IP number

Definition at line 142 of file JNetwork.hh.

  {
    return getIPnumber(getHostname());
  }

std::string JSYSTEM::getIPaddress ( const int  ip )

inline

Get IP address (decimal-dot notation).

Parameters

ip

IP number

Returns

IP address

Definition at line 154 of file JNetwork.hh.

  {
    std::ostringstream os;

    if (compareEndian())
      os << ((ip >> 24) & 0xFF) << '.'
         << ((ip >> 16) & 0xFF) << '.'
         << ((ip >>  8) & 0xFF) << '.'
         << ((ip >>  0) & 0xFF);
    else
      os << ((ip >>  0) & 0xFF) << '.'
         << ((ip >>  8) & 0xFF) << '.'
         << ((ip >> 16) & 0xFF) << '.'
         << ((ip >> 24) & 0xFF);
  
    return os.str();
  }

std::string JSYSTEM::getIPaddress ( )

inline

Get IP address (decimal-dot notation).

Returns

IP address

Definition at line 178 of file JNetwork.hh.

  {
    return getIPaddress(getIPnumber());
  }

unsigned short JSYSTEM::getSubaddress ( const int  ip )

inline

Get host identifier within network.

Parameters

ip

IP number

Returns

ID

Definition at line 190 of file JNetwork.hh.

  {
    if (compareEndian())
      return (unsigned short) (ip & 0x0000FFFF);
    else
      return (unsigned short) (((ip & 0xFF000000) >> 24) |
                               ((ip & 0x00FF0000) >>  8) );
  }

unsigned short JSYSTEM::getSubaddress ( )

inline

Get host identifier within network.

Returns

ID

Definition at line 205 of file JNetwork.hh.

  {
    return getSubaddress(getIPnumber());
  }

std::vector<std::string> JSYSTEM::getListOfIPaddresses ( )

inline

Get list of IP address (decimal-dot notation).

Returns

IP address

Definition at line 216 of file JNetwork.hh.

  {
    using namespace std;
    
    const size_t MAXIMUM_LENGTH = 256;
    char  buffer[MAXIMUM_LENGTH];

    vector<string> result;
    
    struct ifaddrs *p = NULL;

    if (getifaddrs(&p) == 0) {

      for ( ; p != NULL; p = p->ifa_next) {

        if (p->ifa_addr->sa_family == AF_INET  ||
            p->ifa_addr->sa_family == AF_INET6) {

          if (getnameinfo( p->ifa_addr,
                          (p->ifa_addr->sa_family == AF_INET) ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6),
                          buffer, MAXIMUM_LENGTH,
                          NULL, 0, NI_NUMERICHOST) == 0) {

            result.push_back(buffer);
          }
        }
      }
    }

    freeifaddrs(p);

    return result;
  }

float JSYSTEM::getMemoryUsage ( JShell &  shell, const pid_t  pid  )

inline

Get memory usage in percent of given process identifier.

Parameters

shell	shell interface
pid	process identifier

Returns

memory usage [%]

Definition at line 52 of file JSystemToolkit.hh.

  {
    using namespace std;

    float value = 0.0;

    shell << "ps -o %mem= -p " << pid << endl;

    if (shell.get(value))
      return value;
    else
      THROW(JSystemException, "No process data for PID " << pid);
  }

float JSYSTEM::getMemoryUsage ( JShell &  shell )

inline

Get memory usage in percent of this process.

Parameters

shell

shell interface

Returns

memory usage [%]

Definition at line 73 of file JSystemToolkit.hh.

  {
    return getMemoryUsage(shell, getpid());
  }

float JSYSTEM::getMemoryUsage ( )

inline

Get memory usage in percent of this process.

Returns

memory usage [%]

Definition at line 84 of file JSystemToolkit.hh.

  {
    return getMemoryUsage(JShell::getInstance(), getpid());
  }

float JSYSTEM::getCpuUsage ( JShell &  shell, const pid_t  pid  )

inline

Get cpu usage in percent of given process identifier.

Parameters

shell	shell interface
pid	process identifier

Returns

cpu usage [%]

Definition at line 97 of file JSystemToolkit.hh.

  {
    using namespace std;

    float value = 0.0;

    shell << "ps -o %cpu= -p " << pid << endl;

    if (shell.get(value))
      return value;
    else
      THROW(JSystemException, "No process data for PID " << pid);
  }

float JSYSTEM::getCpuUsage ( JShell &  shell )

inline

Get cpu usage in percent of this process.

Parameters

shell

shell interface

Returns

cpu usage [%]

Definition at line 118 of file JSystemToolkit.hh.

  {
    return getCpuUsage(shell, getpid());
  }

float JSYSTEM::getCpuUsage ( )

inline

Get cpu usage in percent of this process.

Returns

cpu usage [%]

Definition at line 129 of file JSystemToolkit.hh.

  {
    return getCpuUsage(JShell::getInstance(), getpid());
  }

pid_t JSYSTEM::getPID ( JShell &  shell, const char *  process  )

inline

Get process identifier.

Parameters

shell	shell interface
process	process name

Returns

process identifier

Definition at line 142 of file JSystemToolkit.hh.

  {
    using namespace std;

    pid_t pid = -1;

    shell << "ps -o pid= -C " << process << endl;

    if (shell.get(pid))
      return pid;
    else
      THROW(JSystemException, "No process " << process);
  }

pid_t JSYSTEM::getPID ( const char *  process )

inline

Get process identifier.

Parameters

process

process name

Returns

process identifier

Definition at line 163 of file JSystemToolkit.hh.

  {
    return getPID(JShell::getInstance(), process);
  }

pid_t JSYSTEM::getParentID ( JShell &  shell, pid_t  pid  )

inline

Get parent process identifier.

Parameters

shell	shell interface
pid	process identifier

Returns

parent identifier

Definition at line 176 of file JSystemToolkit.hh.

  {
    using namespace std;

    shell << "ps -o ppid= -p " << pid << endl;

    if (shell.get(pid))
      return pid;
    else
      THROW(JSystemException, "No parent identifier " << pid);
  }

pid_t JSYSTEM::getParentID ( const pid_t  pid )

inline

Get parent process identifier.

Parameters

pid	process identifier

Returns

parent identifier

Definition at line 195 of file JSystemToolkit.hh.

  {
    return getParentID(JShell::getInstance(), getpid());
  }

std::string JSYSTEM::getShell ( JShell &  shell )

inline

Get shell name.

Parameters

shell

shell interface

Returns

shell name

Definition at line 207 of file JSystemToolkit.hh.

  {
    using namespace std;

    static string value = "";

    if (value == "") {

      pid_t pid = getppid();
        
      shell << "ps -o ppid= -o args= -p " << pid << endl;

      if (shell >> pid >> value) {
      
        shell.flush();
      
        if (!value.empty() && value[0] == '-') {
          value = value.substr(1);
        }

      } else {

        static_cast<istream&>(shell).clear();
        shell.flush();
        
        THROW(JSystemException, "No shell");
      }
    }

    return value;
  }

std::string JSYSTEM::getShell ( )

inline

Get shell name of this process.

Returns

shell name

Definition at line 245 of file JSystemToolkit.hh.

  {
    return getShell(JShell::getInstance());
  }

unsigned long long int JSYSTEM::getRAM ( )

inline

Get RAM of this CPU.

Returns

number of bytes

Definition at line 256 of file JSystemToolkit.hh.

  {
    const JSysinfo info;

    return info.getTotalRAM();
  }

const std::string JSYSTEM::which ( JShell &  shell, const char *  process  )

inline

Get process path.

Parameters

shell	shell interface
process	process name

Returns

path

Definition at line 271 of file JSystemToolkit.hh.

  {
    using namespace std;

    string buffer;
    
    shell << "which " << process << endl;

    shell.getline(buffer);

    shell.flush();

    return buffer;
  }

const std::string JSYSTEM::which ( const char *  process )

inline

Get process path.

Parameters

process

process name

Returns

path

Definition at line 293 of file JSystemToolkit.hh.

  {
    return which(JShell::getInstance(), process);
  }

void JSYSTEM::gprint ( const std::string &  message )

inline

Print method.

Parameters

message

message

Definition at line 331 of file JSystemToolkit.hh.

  {
    using namespace std;

    istringstream is(message);

    for (string buffer; getline(is, buffer); ) {

      if (!buffer.empty()) {

        for (string::size_type i = 0; i != buffer.size(); ++i) {
          if (SPECIAL_CHARACTERS.find(buffer[i]) != string::npos) {
            buffer.insert(i++, "\\");
          }
        }

        cout << "echo " << buffer << ";" << endl;
      }
    }
  }

int JSYSTEM::gexit ( int  status, const std::string &  message = ""  )

inline

Exit method.

Parameters

status	exit status
message	optional message

Definition at line 359 of file JSystemToolkit.hh.

  {
    using namespace std;

    gprint(message);
    
    cout << "exit " << status << ";" << endl;
    
    return status;
  }

void JSYSTEM::set_variable ( const std::string &  name, const std::string &  value  )

inline

Set environment variable.

This method prints the shell command to set the variable with the given name to the specified value.

Parameters

name	variable name
value	variable value

Definition at line 379 of file JSystemToolkit.hh.

  {
    using namespace std;
    using namespace JSYSTEM;
    
    static const string shell = getShell();

    string buffer(value);
    
    if (buffer.find(' ') != string::npos) {
      buffer = "\"" + buffer + "\"";
    }
    
    if        (shell.find(ZSH)  != string::npos ||
               shell.find(KSH)  != string::npos ||
               shell.find(BASH) != string::npos) {
      
      cout << "export " << name << "=" << buffer << ";" << endl;
    
    } else if (shell.find(CSH)  != string::npos ||
               shell.find(TCSH) != string::npos) {
      
      cout << "setenv " << name << " " << buffer << ";" << endl;

    } else {

      THROW(JSystemException, "unknown shell " << shell);
    }
  }

Variable Documentation

JDateAndTime JSYSTEM::getDateAndTime

static

Function object to get ASCII formatted date and time.

Definition at line 295 of file JSystem/JDate.hh.

JGlob JSYSTEM::getFilenames

static

Function object to get list of files for given pattern.

Definition at line 86 of file JGlob.hh.

const JCompareEndian JSYSTEM::compareEndian

static

Function object operator.

Returns

true if network and system endianess same; else false

Definition at line 66 of file JNetwork.hh.

JStat JSYSTEM::getFileStatus

static

Function object for file status.

Definition at line 173 of file JStat.hh.

const char* const JSYSTEM::SH = "sh"

static

Shell names.

Definition at line 34 of file JSystemToolkit.hh.

const char* const JSYSTEM::ZSH = "zsh"

static

Definition at line 35 of file JSystemToolkit.hh.

const char* const JSYSTEM::KSH = "ksh"

static

Definition at line 36 of file JSystemToolkit.hh.

const char* const JSYSTEM::BASH = "bash"

static

Definition at line 37 of file JSystemToolkit.hh.

const char* const JSYSTEM::CSH = "csh"

static

Definition at line 38 of file JSystemToolkit.hh.

const char* const JSYSTEM::TCSH = "tcsh"

static

Definition at line 39 of file JSystemToolkit.hh.

const std::string JSYSTEM::SPECIAL_CHARACTERS = "\"' <>[](){};$#"

static

Definition at line 41 of file JSystemToolkit.hh.

const JLocalTime JSYSTEM::getLocalTime

static

Function object to get local time in micro seconds.

Definition at line 61 of file JSystem/JTime.hh.