Package com.sun.jna.platform.unix
Interface LibCAPI
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
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Nested Class SummaryNested ClassesModifier and TypeInterfaceDescriptionstatic classThis is an unsigned integer type used to represent the sizes of objects.static classThis is a signed integer type used for a count of bytes or an error indication.Nested classes/interfaces inherited from interface com.sun.jna.platform.unix.ResourceResource.Rlimit
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Field SummaryFieldsFields inherited from interface com.sun.jna.platform.unix.RebootRB_AUTOBOOT, RB_DISABLE_CAD, RB_ENABLE_CAD, RB_HALT_SYSTEM, RB_KEXEC, RB_POWER_OFF, RB_SW_SUSPENDFields inherited from interface com.sun.jna.platform.unix.ResourceRLIMIT_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
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Method SummaryModifier and TypeMethodDescriptionintclose(int fd) Closes a file descriptor, so that it no longer refers to any file and may be reused.intgetdomainname(byte[] name, int len) intgetegid()intgeteuid()intgetgid()intgethostname(byte[] name, int len) intgetloadavg(double[] loadavg, int nelem) The getloadavg() function returns the number of processes in the system run queue averaged over various periods of time.intgetuid()intmsync(Pointer addr, LibCAPI.size_t length, int flags) Flushes changes made to the in-core copy of a file that was mapped into memory usingLibCUtil.mmap(Pointer, long, int, int, int, long)back to the filesystem.intmunmap(Pointer addr, LibCAPI.size_t length) Deletes the mappings for the specified address range, and causes further references to addresses within the range to generate invalid memory references.intsetdomainname(String name, int len) intsetegid(int gid) intUpdate or add a variable in the environment of the calling process.intseteuid(int uid) intsetgid(int gid) intsethostname(String name, int len) intsetuid(int uid) int
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Field Details- 
HOST_NAME_MAXstatic final int HOST_NAME_MAX- See Also:
 
 
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Method Details- 
getuidint getuid()
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geteuidint geteuid()
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getgidint getgid()
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getegidint getegid()
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setuidint setuid(int uid) 
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seteuidint seteuid(int uid) 
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setgidint setgid(int gid) 
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setegidint setegid(int gid) 
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gethostnameint gethostname(byte[] name, int len) 
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sethostname
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getdomainnameint getdomainname(byte[] name, int len) 
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setdomainname
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getenv- Parameters:
- name- Environment variable name
- Returns:
- Returns the value in the environment, or nullif there is no match for the name
- See Also:
 
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setenvUpdate 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- overwriteis non-zero, the function shall return success and the environment shall be updated. If the environment variable already exists and the value of- overwriteis 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, errnoset to indicate the error, and the environment shall be unchanged
- See Also:
 
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unsetenv- 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, errnoset to indicate the error, and the environment shall be unchanged
- See Also:
 
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getloadavgint 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:
 
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closeint close(int fd) Closes a file descriptor, so that it no longer refers to any file and may be reused. Any record locks held on the file it was associated with, and owned by the process, are removed (regardless of the file descriptor that was used to obtain the lock).If fdis the last file descriptor referring to the underlying open file description, the resources associated with the open file description are freed; if the file descriptor was the last reference to a file which has been removed usingunlink, the file is deleted.- Parameters:
- fd- a file descriptor
- Returns:
- returns zero on success. On error, -1 is returned, and errnois set appropriately.close()should not be retried after an error.
 
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msyncFlushes changes made to the in-core copy of a file that was mapped into memory usingLibCUtil.mmap(Pointer, long, int, int, int, long)back to the filesystem. Without use of this call, there is no guarantee that changes are written back beforemunmap(Pointer, size_t)is called. To be more precise, the part of the file that corresponds to the memory area starting ataddrand having lengthlengthis updated.- Parameters:
- addr- The start of the memory area to sync to the filesystem.
- length- The length of the memory area to sync to the filesystem.
- flags- The flags argument should specify exactly one of- MS_ASYNCand- MS_SYNC, and may additionally include the- MS_INVALIDATEbit.
- Returns:
- On success, zero is returned. On error, -1 is returned, and
         errnois set appropriately.
 
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munmapDeletes the mappings for the specified address range, and causes further references to addresses within the range to generate invalid memory references. The region is also automatically unmapped when the process is terminated. On the other hand, closing the file descriptor does not unmap the region.It is not an error if the indicated range does not contain any mapped pages. - Parameters:
- addr- The base address from which to delete mappings. The address addr must be a multiple of the page size (but length need not be).
- length- The length from the base address to delete mappings. All pages containing a part of the indicated range are unmapped, and subsequent references to these pages will generate- SIGSEGV.
- Returns:
- On success, returns 0. On failure, it returns -1, and errnois set to indicate the cause of the error (probably toEINVAL).
 
 
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