Package com.sun.jna.platform.unix

Interface LibCAPI

All Superinterfaces:
Reboot, Resource
All Known Subinterfaces:
LibC, LibC, SystemB
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

  • Field Details

  • Method Details

    • 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(String name, int len)

    • getdomainname

      int getdomainname(byte[] name, int len)

    • setdomainname

      int setdomainname(String name, int len)

    • getenv

      String getenv(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:

    • setenv

      int setenv(String name, 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:

    • unsetenv

      int unsetenv(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:

    • 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:

    • close

      int 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 fd is 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 using unlink, the file is deleted.

      Parameters:
      fd - a file descriptor
      Returns:
      returns zero on success. On error, -1 is returned, and errno is set appropriately.

      close() should not be retried after an error.

    • msync

      int msync(Pointer addr, LibCAPI.size_t length, int flags)
      Flushes changes made to the in-core copy of a file that was mapped into memory using LibCUtil.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 before munmap(Pointer, size_t) is called. To be more precise, the part of the file that corresponds to the memory area starting at addr and having length length is 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_ASYNC and MS_SYNC, and may additionally include the MS_INVALIDATE bit.
      Returns:
      On success, zero is returned. On error, -1 is returned, and errno is set appropriately.

    • munmap

      int munmap(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. 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 errno is set to indicate the cause of the error (probably to EINVAL).