org.luaj.vm2.lib.jse
Class JseOsLib

java.lang.Object
  org.luaj.vm2.Varargs
      org.luaj.vm2.LuaValue
          org.luaj.vm2.LuaFunction
              org.luaj.vm2.lib.LibFunction
                  org.luaj.vm2.lib.TwoArgFunction
                      org.luaj.vm2.lib.OsLib
                          org.luaj.vm2.lib.jse.JseOsLib

public class JseOsLib
extends OsLib

Subclass of LibFunction which implements the standard lua os library.

This contains more complete implementations of the following functions using features that are specific to JSE:

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

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.

Typically, this library is included as part of a call to JsePlatform.standardGlobals()

 Globals globals = JsePlatform.standardGlobals();
 System.out.println( globals.get("os").get("time").call() );
  

For special cases where the smallest possible footprint is desired, a minimal set of libraries could be loaded directly via LuaValue.load(LuaValue) using code such as:

 Globals globals = new Globals();
 globals.load(new JseBaseLib());
 globals.load(new PackageLib());
 globals.load(new JseOsLib());
 System.out.println( globals.get("os").get("time").call() );
  

However, other libraries such as MathLib are not loaded in this case.

See Also:

LibFunction, OsLib, JsePlatform, JmePlatform, Lua 5.2 OS Lib Reference

Field Summary

static int	EXEC_ERROR return code indicating the execute() threw an unknown exception
static int	EXEC_INTERRUPTED return code indicating the execute() was interrupted
static int	EXEC_IOEXCEPTION return code indicating the execute() threw an I/O exception

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

globals, TMP_PREFIX, TMP_SUFFIX

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

name, opcode

Fields inherited from class org.luaj.vm2.LuaFunction

s_metatable

Fields inherited from class org.luaj.vm2.LuaValue

ADD, CALL, CONCAT, DIV, EMPTYSTRING, ENV, 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

JseOsLib()
public constructor

Method Summary

protected Varargs	execute(java.lang.String command) This function is equivalent to the C function system.
protected java.lang.String	getenv(java.lang.String varname) Returns the value of the process environment variable varname, or the System property value for varname, or null if the variable is not defined in either environment.
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	tmpname() Returns a string with a file name that can be used for a temporary file.

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

call, clock, date, difftime, exit, setlocale, time

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

call, call, call, invoke

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

bind, bind, call, newupe, newupl, newupn, tojstring

Methods inherited from class org.luaj.vm2.LuaFunction

checkfunction, classnamestub, getmetatable, isfunction, name, optfunction, strvalue, type, typename

Methods inherited from class org.luaj.vm2.LuaValue

add, add, add, and, arg, arg1, argerror, argerror, aritherror, aritherror, arithmt, arithmtwith, assert_, buffer, call, callmt, checkboolean, checkclosure, checkdouble, checkglobals, checkint, checkinteger, checkjstring, checklong, checkmetatag, checknotnil, checknumber, checknumber, checkstring, checktable, checkthread, checkuserdata, checkuserdata, compareerror, compareerror, comparemt, concat, concat, concatmt, concatTo, concatTo, concatTo, div, div, div, divInto, eq_b, eq, eqmtcall, equals, error, get, get, get, gettable, gt_b, gt_b, gt_b, gt, gt, gt, gteq_b, gteq_b, gteq_b, gteq, gteq, gteq, illegal, inext, initupvalue1, invoke, invoke, invoke, invoke, invoke, invokemethod, invokemethod, invokemethod, invokemethod, invokemethod, invokemethod, isboolean, isclosure, isint, isinttype, islong, isnil, isnumber, isstring, istable, isthread, isuserdata, isuserdata, isvalidkey, len, lenerror, length, listOf, listOf, load, lt_b, lt_b, lt_b, lt, lt, lt, lteq_b, lteq_b, lteq_b, lteq, lteq, lteq, metatableOf, metatag, method, method, method, method, method, method, mod, mod, mod, modFrom, mul, mul, mul, narg, neg, neq_b, neq, next, not, onInvoke, 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, rawlen, rawset, rawset, rawset, rawset, rawset, rawset, rawset, rawsetlist, set, set, set, set, set, set, set, setmetatable, settable, strcmp, strcmp, strongvalue, sub, sub, sub, subargs, 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, 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

EXEC_IOEXCEPTION

public static int EXEC_IOEXCEPTION

return code indicating the execute() threw an I/O exception

EXEC_INTERRUPTED

public static int EXEC_INTERRUPTED

return code indicating the execute() was interrupted

EXEC_ERROR

public static int EXEC_ERROR

return code indicating the execute() threw an unknown exception

Constructor Detail

JseOsLib

public JseOsLib()

public constructor

Method Detail

getenv

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

Description copied from class: OsLib

Returns the value of the process environment variable varname, or the System property value for varname, or null if the variable is not defined in either environment. The default implementation, which is used by the JmePlatform, only queryies System.getProperty(). The JsePlatform overrides this behavior and returns the environment variable value using System.getenv() if it exists, or the System property value if it does not. A SecurityException may be thrown if access is not allowed for 'varname'.

Overrides:

getenv in class OsLib

Returns:

String value, or null if not defined

execute

protected Varargs execute(java.lang.String command)

Description copied from class: OsLib

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.

Overrides:

execute in class OsLib

Parameters:

command - command to pass to the system

remove

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

Description copied from class: OsLib

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

Overrides:

remove in class OsLib

Throws:

java.io.IOException - if it fails

rename

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

Description copied from class: OsLib

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

Overrides:

rename in class OsLib

Parameters:

oldname - old file name

newname - new file name

Throws:

java.io.IOException - if it fails

tmpname

protected java.lang.String tmpname()

Description copied from class: OsLib

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).

Overrides:

tmpname in class OsLib

Returns:

String filename to use