qdbm
Class Util

java.lang.Object
  |
  +--qdbm.Util

public class Util
extends java.lang.Object

Class of utility methods.


Method Summary
static int chdir(java.lang.String path)
          Change current working directory using the native function `chdir' defined in POSIX.
static java.lang.Object deserialize(byte[] serial)
          Redintegrate a serialized object.
static long deserializeLong(byte[] serial)
          Redintegrate a serialized long integer.
static java.lang.String getcwd()
          Get current working directory using the native function `getcwd' defined in POSIX.
static int getpid()
          Get process identification using the native function `getpid' defined in POSIX.
static java.lang.String numstr(int num, int cols, char padding)
          Get a formatted decimal string made from a number.
static byte[] serialize(java.lang.Object obj)
          Serialize an object.
static byte[] serializeLong(long num)
          Serialize a long integer.
static int system(java.lang.String cmd)
          Execute a shell command using the native function `system' defined in POSIX and ANSI C.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

chdir

public static int chdir(java.lang.String path)
Change current working directory using the native function `chdir' defined in POSIX.

Parameters:
path - the path of a directory.
Returns:
0 on success, or -1 on failure.

deserialize

public static java.lang.Object deserialize(byte[] serial)
Redintegrate a serialized object.

Parameters:
serial - a byte array of the serialized object.
Returns:
an original object or null if an error occurs.

deserializeLong

public static long deserializeLong(byte[] serial)
                            throws java.lang.IllegalArgumentException
Redintegrate a serialized long integer.

Parameters:
serial - a byte array of a serialized long integer.
Returns:
the long value.
Throws:
java.lang.IllegalArgumentException - thrown if the size of the array is invalid.

getcwd

public static java.lang.String getcwd()
Get current working directory using the native function `getcwd' defined in POSIX.

Returns:
the path of the current working directory or null on failure.

getpid

public static int getpid()
Get process identification using the native function `getpid' defined in POSIX.

Returns:
the process ID of the current process.

numstr

public static java.lang.String numstr(int num,
                                      int cols,
                                      char padding)
Get a formatted decimal string made from a number.

Parameters:
num - a number.
cols - the number of columns. The result string may be longer than it.
padding - a padding character to fulfil columns with.

serialize

public static byte[] serialize(java.lang.Object obj)
Serialize an object.

Parameters:
obj - a serializable object.
Returns:
a byte array of the serialized object or null if an error occurs.

serializeLong

public static byte[] serializeLong(long num)
Serialize a long integer.

Parameters:
num - a long integer.
Returns:
a byte array of the serialized long integer.

system

public static int system(java.lang.String cmd)
Execute a shell command using the native function `system' defined in POSIX and ANSI C.

Returns:
the return value of the function. It depends on the native system.