wiki:KrakenLinuxApi
Last modified 14 months ago

Kraken Linux API

  1. Kraken Linux API
    1. Author
    2. API Reference
      1. Last login (wtmp)
      2. Process
      3. ARP Cache
      4. KernelStat
      5. CpuStat
      6. MemoryStat
      7. NicStat
    3. See Also
    4. History

Kraken Linux API wraps linux native API.

Author

API Reference

Last login (wtmp)

Wtmp class reads /var/log/wtmp log file.

WtmpEntry has following properties: 

public class WtmpEntry {
	public Type getType();
	public int getPid();
	public String getUser();
	public String getHost();
	public int getSession();
	public Date getDate();
}

Type is categorized like this: 

RunLevel, BootTime, NewTime, OldTime, InitProcess, LoginProcess, UserProcess, DeadProcess, Accounting

Usage example: 

for (WtmpEntry entry : Wtmp.getEntries()) {
	System.out.println(entry.toString());
}

result:
type=BootTime, date=2009-08-23 16:16:46, pid=0, user=reboot, host=**deleted**
type=RunLevel, date=2009-08-23 16:16:46, pid=51, user=runlevel, host=**deleted**
type=LoginProcess, date=2009-08-23 16:18:29, pid=1708, user=LOGIN, host=
type=UserProcess, date=2009-08-23 16:18:34, pid=1707, user=root, host=
type=UserProcess, date=2009-08-23 16:25:31, pid=1854, user=root, host=110.45.142.190
type=UserProcess, date=2009-08-23 16:32:18, pid=1916, user=root, host=110.45.142.190
type=LoginProcess, date=2009-08-23 16:44:35, pid=6322, user=LOGIN, host=
type=UserProcess, date=2009-08-23 16:56:55, pid=6322, user=root, host=
type=UserProcess, date=2009-08-23 16:57:13, pid=6451, user=8con, host=110.45.142.190
type=DeadProcess, date=2009-08-23 16:57:22, pid=6451, user=, host=
..omitted..

Process

Process.getProcesses() reads /proc/[pid] directories.

Usage example: 

for (Process p : Process.getProcesses()) {
	System.out.println(p);
}

result:
[1] init, mem=1964KB
[2] kthreadd, mem=0KB
[3] migration/0, mem=0KB
[4] ksoftirqd/0, mem=0KB
[5] watchdog/0, mem=0KB
[6] migration/1, mem=0KB
[7] ksoftirqd/1, mem=0KB
[8] watchdog/1, mem=0KB
..omitted..

ARP Cache

ArpCache class reads /proc/net/arp and returns arp entries.

ArpEntry has following fields: 

public class ArpEntry {
	public String getIp();
	public int getHwType();
	public String getFlags();
	public String getMac();
	public String getMask();
	public String getDevice();
}

Usage example: 

for (ArpEntry e : ArpCache.getEntries()) {
	System.out.println(e);
}

result:
device=eth0, ip=110.45.142.130, mac=00:21:5e:4d:ce:f8
device=eth0, ip=110.45.142.129, mac=00:0f:35:6c:f8:00

KernelStat

KernelStat has following members: 

public class KernelStat {
	public CpuStat getCpu();
	public List<CpuStat> getCpus();
	public long getPagedIn();
	public long getPagedOut();
	public long getSwapIn();
	public long getSwapOut();
	public long getTotalInterrupts();
	public List<Long> getParticularInterrupts();
	public long getContext();
	public long getBootTime();
	public int getProcesses();
	public int getRunningProcess();
	public int getBlockedProcess();

	public static KernelStat getKernelStat() throws IOException;
}

CpuStat

CpuStat reads /proc/stat and returns cpu statistics.

Usage example: 

CpuUsage usage = CpuStat.getCpuUsage();
System.out.println(usage);

result:
idle=94, system=4, user=2

MemoryStat

MemoryStat reads /proc/meminfo file.

Usage example: 

MemoryStat mem = MemoryStat.getMemoryStat();
System.out.println(mem);

result:
MemTotal:        2062560 kB
MemFree:          181248 kB
Buffers:          285712 kB
Cached:           589912 kB
SwapCached:         3484 kB
Active:          1131132 kB
Inactive:         634160 kB
Active(anon):     643200 kB
Inactive(anon):   247108 kB
Active(file):     487932 kB
Inactive(file):   387052 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:       4112376 kB
SwapFree:        4037532 kB
Dirty:                68 kB
Writeback:             4 kB
AnonPages:        886336 kB
Mapped:            26216 kB
Slab:              82316 kB
SReclaimable:      73136 kB
SUnreclaim:         9180 kB
PageTables:         7376 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:     5143656 kB
Committed_AS:    1662492 kB
VmallocTotal:     122880 kB
VmallocUsed:       10012 kB
VmallocChunk:     109172 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB
DirectMap4k:       10232 kB
DirectMap2M:      899072 kB

This output is exactly same with cat /proc/meminfo .

NicStat

NicStat reads /proc/net/dev and returns nic statistics.

NicStat has following members: 

public class NicStat {
	public String getName();
	public long getRxBytes();
	public long getRxPackets();
	public long getRxErrors();
	public long getRxDrops();
	public long getRxFifo();
	public long getRxFifo();
	public long getRxFrames();
	public long getRxCompressed();
	public long getRxMulticast();

	public long getTxBytes();
	public long getTxPackets();
	public long getTxErrors();
	public long getTxDrops();
	public long getTxFifo();
	public long getTxColls();
	public long getTxCarrier();
	public long getTxCompressed();

	public static List<NicStat> getNicStats() throws IOException;
}

Usage example: 

for (NicStat nic : NicStat.getNicStats()) {
	System.out.println(nic);
}

result:
name=lo, rxBytes=3718687677, rxCompressed=0, rxDrops=0, rxErrors=0, rxFifo=0, rxFrames=0, rxMulticast=0, rxPackets=5191486, txBytes=3718687677, txCarrier=0, txColls=0, txCompressed=0, txDrops=0, txErrors=0, txFifo=0, txPackets=5191486
name=eth0, rxBytes=2552935457, rxCompressed=0, rxDrops=0, rxErrors=336875, rxFifo=0, rxFrames=188013, rxMulticast=22962596, rxPackets=703942274, txBytes=1039311310, txCarrier=0, txColls=0, txCompressed=0, txDrops=0, txErrors=0, txFifo=0, txPackets=1049547749
name=eth1, rxBytes=0, rxCompressed=0, rxDrops=0, rxErrors=0, rxFifo=0, rxFrames=0, rxMulticast=0, rxPackets=0, txBytes=0, txCarrier=0, txColls=0, txCompressed=0, txDrops=0, txErrors=0, txFifo=0, txPackets=0
..omitted..

See Also

History

  • 1.0.0 release (2010-12-24)