com.sun.jna.platform.unix

Interface LibCAPI

All Superinterfaces:

Reboot, Resource

All Known Subinterfaces:

LibC, LibC

public interface LibCAPI
extends Reboot, Resource

Note: we are using this "intermediate" API in order to allow Linux-like O/S-es to implement the same API, but maybe using a different library name

Author:

Lyor Goldstein

Nested Class Summary

Nested classes/interfaces inherited from interface com.sun.jna.platform.unix.Resource

Resource.Rlimit

Field Summary

Fields

Modifier and Type	Field and Description
static int	HOST_NAME_MAX

Fields inherited from interface com.sun.jna.platform.unix.Reboot

RB_AUTOBOOT, RB_DISABLE_CAD, RB_ENABLE_CAD, RB_HALT_SYSTEM, RB_KEXEC, RB_POWER_OFF, RB_SW_SUSPEND

Fields inherited from interface com.sun.jna.platform.unix.Resource

RLIMIT_AS, RLIMIT_CORE, RLIMIT_CPU, RLIMIT_DATA, RLIMIT_FSIZE, RLIMIT_LOCKS, RLIMIT_MEMLOCK, RLIMIT_MSGQUEUE, RLIMIT_NICE, RLIMIT_NLIMITS, RLIMIT_NOFILE, RLIMIT_NPROC, RLIMIT_RSS, RLIMIT_RTPRIO, RLIMIT_RTTIME, RLIMIT_SIGPENDING, RLIMIT_STACK

Method Summary

Modifier and Type	Method and Description
int	getdomainname(byte[] name, int len)
int	getegid()
java.lang.String	getenv(java.lang.String name)
int	geteuid()
int	getgid()
int	gethostname(byte[] name, int len)
int	getloadavg(double[] loadavg, int nelem) The getloadavg() function returns the number of processes in the system run queue averaged over various periods of time.
int	getuid()
int	setdomainname(java.lang.String name, int len)
int	setegid(int gid)
int	setenv(java.lang.String name, java.lang.String value, int overwrite) Update or add a variable in the environment of the calling process.
int	seteuid(int uid)
int	setgid(int gid)
int	sethostname(java.lang.String name, int len)
int	setuid(int uid)
int	unsetenv(java.lang.String name)

Methods inherited from interface com.sun.jna.platform.unix.Reboot

reboot

Methods inherited from interface com.sun.jna.platform.unix.Resource

getrlimit, setrlimit

Field Detail

HOST_NAME_MAX

static final int HOST_NAME_MAX

See Also:

Constant Field Values

Method Detail

getuid

int getuid()

geteuid

int geteuid()

getgid

int getgid()

getegid

int getegid()

setuid

int setuid(int uid)

seteuid

int seteuid(int uid)

setgid

int setgid(int gid)

setegid

int setegid(int gid)

gethostname

int gethostname(byte[] name,
                int len)

sethostname

int sethostname(java.lang.String name,
                int len)

getdomainname

int getdomainname(byte[] name,
                  int len)

setdomainname

int setdomainname(java.lang.String name,
                  int len)

getenv

java.lang.String getenv(java.lang.String name)

Parameters:

name - Environment variable name

Returns:

Returns the value in the environment, or null if there is no match for the name

See Also:

getenv(3)

setenv

int setenv(java.lang.String name,
           java.lang.String value,
           int overwrite)

Update or add a variable in the environment of the calling process.

Parameters:

name - Environment variable name

value - Required value

overwrite - If the environment variable already exists and the value of overwrite is non-zero, the function shall return success and the environment shall be updated. If the environment variable already exists and the value of overwrite is zero, the function shall return success and the environment shall remain unchanged.

Returns:

Upon successful completion, zero shall be returned. Otherwise, -1 shall be returned, errno set to indicate the error, and the environment shall be unchanged

See Also:

getenv(3)

unsetenv

int unsetenv(java.lang.String name)

Parameters:

name - Environment variable name - If the named variable does not exist in the current environment, the environment shall be unchanged and the function is considered to have completed successfully.

Returns:

Upon successful completion, zero shall be returned. Otherwise, -1 shall be returned, errno set to indicate the error, and the environment shall be unchanged

See Also:

getenv(3)

getloadavg

int getloadavg(double[] loadavg,
               int nelem)

The getloadavg() function returns the number of processes in the system run queue averaged over various periods of time. Up to nelem samples are retrieved and assigned to successive elements of loadavg[]. The system imposes a maximum of 3 samples, representing averages over the last 1, 5, and 15 minutes, respectively.

Parameters:

loadavg - An array of doubles which will be filled with the results

nelem - Number of samples to return

Returns:

If the load average was unobtainable, -1 is returned; otherwise, the number of samples actually retrieved is returned.

See Also:

getloadavg(3)