org.luaj.vm2.lib.OsLib Maven / Gradle / Ivy
Show all versions of luaj-jse Show documentation
/*******************************************************************************
* Copyright (c) 2009 Luaj.org. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
******************************************************************************/
package org.luaj.vm2.lib;
import java.io.IOException;
import java.util.Calendar;
import java.util.Date;
import org.luaj.vm2.Buffer;
import org.luaj.vm2.Globals;
import org.luaj.vm2.LuaTable;
import org.luaj.vm2.LuaValue;
import org.luaj.vm2.Varargs;
/**
* Subclass of {@link LibFunction} which implements the standard lua {@code 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 {@code 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:
*
* - {@code execute()}
* - {@code remove()}
* - {@code rename()}
* - {@code tmpname()}
*
*
* Typically, this library is included as part of a call to either
* {@link org.luaj.vm2.lib.jse.JsePlatform#standardGlobals()} or {@link org.luaj.vm2.lib.jme.JmePlatform#standardGlobals()}
*
{@code
* Globals globals = JsePlatform.standardGlobals();
* System.out.println( globals.get("os").get("time").call() );
* }
* In this example the platform-specific {@link org.luaj.vm2.lib.jse.JseOsLib} library will be loaded, which will include
* the base functionality provided by this class.
*
* To instantiate and use it directly,
* link it into your globals table via {@link LuaValue#load(LuaValue)} using code such as:
*
{@code
* Globals globals = new Globals();
* globals.load(new JseBaseLib());
* globals.load(new PackageLib());
* globals.load(new OsLib());
* System.out.println( globals.get("os").get("time").call() );
* }
*
* @see LibFunction
* @see org.luaj.vm2.lib.jse.JseOsLib
* @see org.luaj.vm2.lib.jse.JsePlatform
* @see org.luaj.vm2.lib.jme.JmePlatform
* @see http://www.lua.org/manual/5.1/manual.html#5.8
*/
public class OsLib extends TwoArgFunction {
public static String TMP_PREFIX = ".luaj";
public static String TMP_SUFFIX = "tmp";
private static final int CLOCK = 0;
private static final int DATE = 1;
private static final int DIFFTIME = 2;
private static final int EXECUTE = 3;
private static final int EXIT = 4;
private static final int GETENV = 5;
private static final int REMOVE = 6;
private static final int RENAME = 7;
private static final int SETLOCALE = 8;
private static final int TIME = 9;
private static final int TMPNAME = 10;
private static final String[] NAMES = {
"clock",
"date",
"difftime",
"execute",
"exit",
"getenv",
"remove",
"rename",
"setlocale",
"time",
"tmpname",
};
private static final long t0 = System.currentTimeMillis();
private static long tmpnames = t0;
protected Globals globals;
/**
* Create and OsLib instance.
*/
public OsLib() {
}
/** Perform one-time initialization on the library by creating a table
* containing the library functions, adding that table to the supplied environment,
* adding the table to package.loaded, and returning table as the return value.
* @param modname the module name supplied if this is loaded via 'require'.
* @param env the environment to load into, typically a Globals instance.
*/
public LuaValue call(LuaValue modname, LuaValue env) {
globals = env.checkglobals();
LuaTable os = new LuaTable();
for (int i = 0; i < NAMES.length; ++i)
os.set(NAMES[i], new OsLibFunc(i, NAMES[i]));
env.set("os", os);
env.get("package").get("loaded").set("os", os);
return os;
}
class OsLibFunc extends VarArgFunction {
public OsLibFunc(int opcode, String name) {
this.opcode = opcode;
this.name = name;
}
public Varargs invoke(Varargs args) {
try {
switch ( opcode ) {
case CLOCK:
return valueOf(clock());
case DATE: {
String s = args.optjstring(1, "%c");
double t = args.isnumber(2)? args.todouble(2): time(null);
if (s.equals("*t")) {
Calendar d = Calendar.getInstance();
d.setTime(new Date((long)(t*1000)));
LuaTable tbl = LuaValue.tableOf();
tbl.set("year", LuaValue.valueOf(d.get(Calendar.YEAR)));
tbl.set("month", LuaValue.valueOf(d.get(Calendar.MONTH)+1));
tbl.set("day", LuaValue.valueOf(d.get(Calendar.DAY_OF_MONTH)));
tbl.set("hour", LuaValue.valueOf(d.get(Calendar.HOUR_OF_DAY)));
tbl.set("min", LuaValue.valueOf(d.get(Calendar.MINUTE)));
tbl.set("sec", LuaValue.valueOf(d.get(Calendar.SECOND)));
tbl.set("wday", LuaValue.valueOf(d.get(Calendar.DAY_OF_WEEK)));
tbl.set("yday", LuaValue.valueOf(d.get(0x6))); // Day of year
tbl.set("isdst", LuaValue.valueOf(isDaylightSavingsTime(d)));
return tbl;
}
return valueOf( date(s, t==-1? time(null): t) );
}
case DIFFTIME:
return valueOf(difftime(args.checkdouble(1),args.checkdouble(2)));
case EXECUTE:
return execute(args.optjstring(1, null));
case EXIT:
exit(args.optint(1, 0));
return NONE;
case GETENV: {
final String val = getenv(args.checkjstring(1));
return val!=null? valueOf(val): NIL;
}
case REMOVE:
remove(args.checkjstring(1));
return LuaValue.TRUE;
case RENAME:
rename(args.checkjstring(1), args.checkjstring(2));
return LuaValue.TRUE;
case SETLOCALE: {
String s = setlocale(args.optjstring(1,null), args.optjstring(2, "all"));
return s!=null? valueOf(s): NIL;
}
case TIME:
return valueOf(time(args.opttable(1, null)));
case TMPNAME:
return valueOf(tmpname());
}
return NONE;
} catch ( IOException e ) {
return varargsOf(NIL, valueOf(e.getMessage()));
}
}
}
/**
* @return an approximation of the amount in seconds of CPU time used by
* the program. For luaj this simple returns the elapsed time since the
* OsLib class was loaded.
*/
protected double clock() {
return (System.currentTimeMillis()-t0) / 1000.;
}
/**
* Returns the number of seconds from time t1 to time t2.
* In POSIX, Windows, and some other systems, this value is exactly t2-t1.
* @param t2
* @param t1
* @return diffeence in time values, in seconds
*/
protected double difftime(double t2, double t1) {
return t2 - t1;
}
/**
* 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.
*
* Date returns the date as a string,
* formatted according to the same rules as ANSII strftime, but without
* support for %g, %G, or %V.
*
* 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")).
*
* @param format
* @param time time since epoch, or -1 if not supplied
* @return a LString or a LTable containing date and time,
* formatted according to the given string format.
*/
public String date(String format, double time) {
Calendar d = Calendar.getInstance();
d.setTime(new Date((long)(time*1000)));
if (format.startsWith("!")) {
time -= timeZoneOffset(d);
d.setTime(new Date((long)(time*1000)));
format = format.substring(1);
}
byte[] fmt = format.getBytes();
final int n = fmt.length;
Buffer result = new Buffer(n);
byte c;
for ( int i = 0; i < n; ) {
switch ( c = fmt[i++ ] ) {
case '\n':
result.append( "\n" );
break;
default:
result.append( c );
break;
case '%':
if (i >= n) break;
switch ( c = fmt[i++ ] ) {
default:
LuaValue.argerror(1, "invalid conversion specifier '%"+c+"'");
break;
case '%':
result.append( (byte)'%' );
break;
case 'a':
result.append(WeekdayNameAbbrev[d.get(Calendar.DAY_OF_WEEK)-1]);
break;
case 'A':
result.append(WeekdayName[d.get(Calendar.DAY_OF_WEEK)-1]);
break;
case 'b':
result.append(MonthNameAbbrev[d.get(Calendar.MONTH)]);
break;
case 'B':
result.append(MonthName[d.get(Calendar.MONTH)]);
break;
case 'c':
result.append(date("%a %b %d %H:%M:%S %Y", time));
break;
case 'd':
result.append(String.valueOf(100+d.get(Calendar.DAY_OF_MONTH)).substring(1));
break;
case 'H':
result.append(String.valueOf(100+d.get(Calendar.HOUR_OF_DAY)).substring(1));
break;
case 'I':
result.append(String.valueOf(100+(d.get(Calendar.HOUR_OF_DAY)%12)).substring(1));
break;
case 'j': { // day of year.
Calendar y0 = beginningOfYear(d);
int dayOfYear = (int) ((d.getTime().getTime() - y0.getTime().getTime()) / (24 * 3600L * 1000L));
result.append(String.valueOf(1001+dayOfYear).substring(1));
break;
}
case 'm':
result.append(String.valueOf(101+d.get(Calendar.MONTH)).substring(1));
break;
case 'M':
result.append(String.valueOf(100+d.get(Calendar.MINUTE)).substring(1));
break;
case 'p':
result.append(d.get(Calendar.HOUR_OF_DAY) < 12? "AM": "PM");
break;
case 'S':
result.append(String.valueOf(100+d.get(Calendar.SECOND)).substring(1));
break;
case 'U':
result.append(String.valueOf(weekNumber(d, 0)));
break;
case 'w':
result.append(String.valueOf((d.get(Calendar.DAY_OF_WEEK)+6)%7));
break;
case 'W':
result.append(String.valueOf(weekNumber(d, 1)));
break;
case 'x':
result.append(date("%m/%d/%y", time));
break;
case 'X':
result.append(date("%H:%M:%S", time));
break;
case 'y':
result.append(String.valueOf(d.get(Calendar.YEAR)).substring(2));
break;
case 'Y':
result.append(String.valueOf(d.get(Calendar.YEAR)));
break;
case 'z': {
final int tzo = timeZoneOffset(d) / 60;
final int a = Math.abs(tzo);
final String h = String.valueOf(100 + a / 60).substring(1);
final String m = String.valueOf(100 + a % 60).substring(1);
result.append((tzo>=0? "+": "-") + h + m);
break;
}
}
}
}
return result.tojstring();
}
private static final String[] WeekdayNameAbbrev = { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" };
private static final String[] WeekdayName = { "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday" };
private static final String[] MonthNameAbbrev = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
private static final String[] MonthName = { "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December" };
private Calendar beginningOfYear(Calendar d) {
Calendar y0 = Calendar.getInstance();
y0.setTime(d.getTime());
y0.set(Calendar.MONTH, 0);
y0.set(Calendar.DAY_OF_MONTH, 1);
y0.set(Calendar.HOUR_OF_DAY, 0);
y0.set(Calendar.MINUTE, 0);
y0.set(Calendar.SECOND, 0);
y0.set(Calendar.MILLISECOND, 0);
return y0;
}
private int weekNumber(Calendar d, int startDay) {
Calendar y0 = beginningOfYear(d);
y0.set(Calendar.DAY_OF_MONTH, 1 + (startDay + 8 - y0.get(Calendar.DAY_OF_WEEK)) % 7);
if (y0.after(d)) {
y0.set(Calendar.YEAR, y0.get(Calendar.YEAR) - 1);
y0.set(Calendar.DAY_OF_MONTH, 1 + (startDay + 8 - y0.get(Calendar.DAY_OF_WEEK)) % 7);
}
long dt = d.getTime().getTime() - y0.getTime().getTime();
return 1 + (int) (dt / (7L * 24L * 3600L * 1000L));
}
private int timeZoneOffset(Calendar d) {
int localStandarTimeMillis = (
d.get(Calendar.HOUR_OF_DAY) * 3600 +
d.get(Calendar.MINUTE) * 60 +
d.get(Calendar.SECOND)) * 1000;
return d.getTimeZone().getOffset(
1,
d.get(Calendar.YEAR),
d.get(Calendar.MONTH),
d.get(Calendar.DAY_OF_MONTH),
d.get(Calendar.DAY_OF_WEEK),
localStandarTimeMillis) / 1000;
}
private boolean isDaylightSavingsTime(Calendar d) {
return timeZoneOffset(d) != d.getTimeZone().getRawOffset() / 1000;
}
/**
* 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.
* @param command command to pass to the system
*/
protected Varargs execute(String command) {
return varargsOf(NIL, valueOf("exit"), ONE);
}
/**
* Calls the C function exit, with an optional code, to terminate the host program.
* @param code
*/
protected void exit(int code) {
System.exit(code);
}
/**
* 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'.
* @param varname
* @return String value, or null if not defined
*/
protected String getenv(String varname) {
return System.getProperty(varname);
}
/**
* Deletes the file or directory with the given name.
* Directories must be empty to be removed.
* If this function fails, it throws and IOException
*
* @param filename
* @throws IOException if it fails
*/
protected void remove(String filename) throws IOException {
throw new IOException( "not implemented" );
}
/**
* Renames file or directory named oldname to newname.
* If this function fails,it throws and IOException
*
* @param oldname old file name
* @param newname new file name
* @throws IOException if it fails
*/
protected void rename(String oldname, String newname) throws IOException {
throw new IOException( "not implemented" );
}
/**
* 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.
*
* @param locale
* @param category
* @return the name of the new locale, or null if the request
* cannot be honored.
*/
protected String setlocale(String locale, String category) {
return "C";
}
/**
* 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).
* @param table
* @return long value for the time
*/
protected double time(LuaTable table) {
java.util.Date d;
if (table == null) {
d = new java.util.Date();
} else {
Calendar c = Calendar.getInstance();
c.set(Calendar.YEAR, table.get("year").checkint());
c.set(Calendar.MONTH, table.get("month").checkint()-1);
c.set(Calendar.DAY_OF_MONTH, table.get("day").checkint());
c.set(Calendar.HOUR_OF_DAY, table.get("hour").optint(12));
c.set(Calendar.MINUTE, table.get("min").optint(0));
c.set(Calendar.SECOND, table.get("sec").optint(0));
c.set(Calendar.MILLISECOND, 0);
d = c.getTime();
}
return d.getTime() / 1000.;
}
/**
* 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).
*
* @return String filename to use
*/
protected String tmpname() {
synchronized ( OsLib.class ) {
return TMP_PREFIX+(tmpnames++)+TMP_SUFFIX;
}
}
}