org.luaj.vm2.lib
Class OsLib

java.lang.Object
  org.luaj.vm2.Varargs
      org.luaj.vm2.LuaValue
          org.luaj.vm2.LuaFunction
              org.luaj.vm2.lib.LibFunction
                  org.luaj.vm2.lib.VarArgFunction
                      org.luaj.vm2.lib.OsLib

Direct Known Subclasses:

JseOsLib

public class OsLib
extends VarArgFunction

Subclass of LibFunction which implements the standard lua os library.

It is a usable base with simplified stub functions for library functions that cannot be implemented uniformly on Jse and Jme.

This can be installed as-is on either platform, or extended and refined to be used in a complete Jse implementation.

Because the nature of the os library is to encapsulate os-specific features, the behavior of these functions varies considerably from their counterparts in the C platform.

The following functions have limited implementations of features that are not supported well on Jme:

• execute()
• remove()
• rename()
• tmpname()

Typically, this library is included as part of a call to either JmePlatform#standardGlobals()

To instantiate and use it directly, link it into your globals table via LuaValue.load(LuaValue) using code such as:

 LuaTable _G = new LuaTable();
 LuaThread.setGlobals(_G);
 _G.load(new BaseLib());
 _G.load(new PackageLib());
 _G.load(new OsLib());
 System.out.println( _G.get("os").get("time").call() );
  

Doing so will ensure the library is properly initialized and loaded into the globals table.

See Also:

LibFunction, JseOsLib, JsePlatform, JmePlatform, http://www.lua.org/manual/5.1/manual.html#5.8

Field Summary

static java.lang.String	TMP_PREFIX
static java.lang.String	TMP_SUFFIX

Fields inherited from class org.luaj.vm2.lib.LibFunction

name, opcode

Fields inherited from class org.luaj.vm2.LuaFunction

env, s_metatable

Fields inherited from class org.luaj.vm2.LuaValue

ADD, CALL, CONCAT, DIV, EMPTYSTRING, EQ, FALSE, INDEX, LE, LEN, LT, METATABLE, MINUSONE, MOD, MODE, MUL, NEWINDEX, NIL, NILS, NONE, NOVALS, ONE, POW, SUB, TBOOLEAN, TFUNCTION, TINT, TLIGHTUSERDATA, TNIL, TNONE, TNUMBER, TOSTRING, TRUE, TSTRING, TTABLE, TTHREAD, TUSERDATA, TVALUE, TYPE_NAMES, UNM, ZERO

Constructor Summary

OsLib()
Create and OsLib instance.

Method Summary

protected double	clock()
protected java.lang.String	date(java.lang.String format, double time) If the time argument is present, this is the time to be formatted (see the os.time function for a description of this value).
protected double	difftime(double t2, double t1) Returns the number of seconds from time t1 to time t2.
protected int	execute(java.lang.String command) This function is equivalent to the C function system.
protected void	exit(int code) Calls the C function exit, with an optional code, to terminate the host program.
protected java.lang.String	getenv(java.lang.String varname) Returns the value of the process environment variable varname, or null if the variable is not defined.
LuaValue	init()
Varargs	invoke(Varargs args) Override and implement for the best performance.
protected void	remove(java.lang.String filename) Deletes the file or directory with the given name.
protected void	rename(java.lang.String oldname, java.lang.String newname) Renames file or directory named oldname to newname.
protected java.lang.String	setlocale(java.lang.String locale, java.lang.String category) Sets the current locale of the program.
protected long	time(LuaTable table) Returns the current time when called without arguments, or a time representing the date and time specified by the given table.
protected java.lang.String	tmpname() Returns a string with a file name that can be used for a temporary file.

Methods inherited from class org.luaj.vm2.lib.VarArgFunction

call, call, call, call, onInvoke

Methods inherited from class org.luaj.vm2.lib.LibFunction

bind, bind, newupe, newupl, newupn, tojstring

Methods inherited from class org.luaj.vm2.LuaFunction

checkfunction, getfenv, getmetatable, isfunction, optfunction, setfenv, type, typename

Methods inherited from class org.luaj.vm2.LuaValue

add, add, add, and, arg, arg1, argerror, argerror, aritherror, aritherror, arithmt, arithmtwith, assert_, buffer, callmt, checkboolean, checkclosure, checkdouble, checkint, checkinteger, checkjstring, checklong, checkmetatag, checknotnil, checknumber, checknumber, checkstring, checktable, checkthread, checkuserdata, checkuserdata, checkvalidkey, compareerror, compareerror, comparemt, concat, concat, concatmt, concatTo, concatTo, concatTo, div, div, div, divInto, eq_b, eq, eqmtcall, equals, error, get, get, get, getn, gettable, gt_b, gt_b, gt_b, gt, gt, gt, gteq_b, gteq_b, gteq_b, gteq, gteq, gteq, illegal, inext, invoke, invoke, invoke, invoke, invoke, invokemethod, invokemethod, invokemethod, invokemethod, invokemethod, invokemethod, isboolean, isclosure, isint, isinttype, islong, isnil, isnumber, isstring, istable, isthread, isuserdata, isuserdata, isweaknil, len, lenerror, length, listOf, listOf, load, lt_b, lt_b, lt_b, lt, lt, lt, lteq_b, lteq_b, lteq_b, lteq, lteq, lteq, metatag, method, method, method, method, method, method, mod, mod, mod, modFrom, mul, mul, mul, narg, neg, neq_b, neq, next, not, optboolean, optclosure, optdouble, optint, optinteger, optjstring, optlong, optnumber, optstring, opttable, optthread, optuserdata, optuserdata, optvalue, or, pow, pow, pow, powWith, powWith, presize, raweq, raweq, raweq, raweq, raweq, rawget, rawget, rawget, rawset, rawset, rawset, rawset, rawset, rawset, rawset, rawsetlist, set, set, set, set, set, set, set, setmetatable, settable, strcmp, strcmp, strongkey, strongvalue, strvalue, sub, sub, sub, subFrom, subFrom, tableOf, tableOf, tableOf, tableOf, tableOf, tableOf, tailcallOf, testfor_b, toboolean, tobyte, tochar, todouble, tofloat, toint, tolong, tonumber, toshort, tostring, toString, touserdata, touserdata, typerror, unimplemented, userdataOf, userdataOf, valueOf, valueOf, valueOf, valueOf, valueOf, valueOf, varargsOf, varargsOf, varargsOf, varargsOf, varargsOf, varargsOf

Methods inherited from class org.luaj.vm2.Varargs

argcheck, checkboolean, checkclosure, checkdouble, checkfunction, checkint, checkinteger, checkjstring, checklong, checknotnil, checknumber, checkstring, checktable, checkthread, checkuserdata, checkuserdata, checkvalue, eval, isfunction, isnil, isnoneornil, isnumber, isstring, istable, isTailcall, isthread, isuserdata, isvalue, optboolean, optclosure, optdouble, optfunction, optint, optinteger, optjstring, optlong, optnumber, optstring, opttable, optthread, optuserdata, optuserdata, optvalue, subargs, toboolean, tobyte, tochar, todouble, tofloat, toint, tojstring, tolong, toshort, touserdata, touserdata, type

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

TMP_PREFIX

public static java.lang.String TMP_PREFIX

TMP_SUFFIX

public static java.lang.String TMP_SUFFIX

Constructor Detail

OsLib

public OsLib()

Create and OsLib instance.

Method Detail

init

public LuaValue init()

invoke

public Varargs invoke(Varargs args)

Description copied from class: VarArgFunction

Override and implement for the best performance. May not have expected behavior for tail calls. Should not be used if either: - function needs to be used as a module - function has a possibility of returning a TailcallVarargs

Overrides:

invoke in class VarArgFunction

Parameters:

args - the arguments to the function call.

Returns:

All return values as a Varargs instance.

See Also:

LuaValue.varargsOf(LuaValue[]), LuaValue.call(LuaValue), LuaValue.invoke(), LuaValue.invoke(LuaValue,Varargs), LuaValue.invokemethod(String,Varargs), LuaValue.invokemethod(LuaValue,Varargs)

clock

protected double clock()

Returns:

an approximation of the amount in seconds of CPU time used by the program.

difftime

protected double difftime(double t2,
                          double t1)

Returns the number of seconds from time t1 to time t2. In POSIX, Windows, and some other systems, this value is exactly t2-t1.

Parameters:

t2 -

t1 -

Returns:

diffeence in time values, in seconds

date

protected java.lang.String date(java.lang.String format,
                                double time)

If the time argument is present, this is the time to be formatted (see the os.time function for a description of this value). Otherwise, date formats the current time. If format starts with '!', then the date is formatted in Coordinated Universal Time. After this optional character, if format is the string "*t", then date returns a table with the following fields: year (four digits), month (1--12), day (1--31), hour (0--23), min (0--59), sec (0--61), wday (weekday, Sunday is 1), yday (day of the year), and isdst (daylight saving flag, a boolean). If format is not "*t", then date returns the date as a string, formatted according to the same rules as the C function strftime. When called without arguments, date returns a reasonable date and time representation that depends on the host system and on the current locale (that is, os.date() is equivalent to os.date("%c")).

Parameters:

format -

time - time since epoch, or -1 if not supplied

Returns:

a LString or a LTable containing date and time, formatted according to the given string format.

execute

protected int execute(java.lang.String command)

This function is equivalent to the C function system. It passes command to be executed by an operating system shell. It returns a status code, which is system-dependent. If command is absent, then it returns nonzero if a shell is available and zero otherwise.

Parameters:

command - command to pass to the system

exit

protected void exit(int code)

Calls the C function exit, with an optional code, to terminate the host program.

Parameters:

code -

getenv

protected java.lang.String getenv(java.lang.String varname)

Returns the value of the process environment variable varname, or null if the variable is not defined.

Parameters:

varname -

Returns:

String value, or null if not defined

remove

protected void remove(java.lang.String filename)
               throws java.io.IOException

Deletes the file or directory with the given name. Directories must be empty to be removed. If this function fails, it throws and IOException

Parameters:

filename -

Throws:

java.io.IOException - if it fails

rename

protected void rename(java.lang.String oldname,
                      java.lang.String newname)
               throws java.io.IOException

Renames file or directory named oldname to newname. If this function fails,it throws and IOException

Parameters:

oldname - old file name

newname - new file name

Throws:

java.io.IOException - if it fails

setlocale

protected java.lang.String setlocale(java.lang.String locale,
                                     java.lang.String category)

Sets the current locale of the program. locale is a string specifying a locale; category is an optional string describing which category to change: "all", "collate", "ctype", "monetary", "numeric", or "time"; the default category is "all". If locale is the empty string, the current locale is set to an implementation- defined native locale. If locale is the string "C", the current locale is set to the standard C locale. When called with null as the first argument, this function only returns the name of the current locale for the given category.

Parameters:

locale -

category -

Returns:

the name of the new locale, or null if the request cannot be honored.

time

protected long time(LuaTable table)

Returns the current time when called without arguments, or a time representing the date and time specified by the given table. This table must have fields year, month, and day, and may have fields hour, min, sec, and isdst (for a description of these fields, see the os.date function).

Parameters:

table -

Returns:

long value for the time

tmpname

protected java.lang.String tmpname()

Returns a string with a file name that can be used for a temporary file. The file must be explicitly opened before its use and explicitly removed when no longer needed. On some systems (POSIX), this function also creates a file with that name, to avoid security risks. (Someone else might create the file with wrong permissions in the time between getting the name and creating the file.) You still have to open the file to use it and to remove it (even if you do not use it).

Returns:

String filename to use