001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.io;
018
019import java.io.BufferedReader;
020import java.io.IOException;
021import java.io.InputStream;
022import java.io.InputStreamReader;
023import java.io.OutputStream;
024import java.nio.charset.Charset;
025import java.time.Duration;
026import java.util.Arrays;
027import java.util.List;
028import java.util.Locale;
029import java.util.Objects;
030import java.util.StringTokenizer;
031import java.util.stream.Collectors;
032
033/**
034 * General File System utilities.
035 * <p>
036 * This class provides static utility methods for general file system
037 * functions not provided via the JDK {@link java.io.File File} class.
038 * <p>
039 * The current functions provided are:
040 * <ul>
041 * <li>Get the free space on a drive
042 * </ul>
043 *
044 * @since 1.1
045 * @deprecated As of 2.6 deprecated without replacement. Use equivalent
046 *  methods in {@link java.nio.file.FileStore} instead, e.g.
047 *  {@code Files.getFileStore(Paths.get("/home")).getUsableSpace()}
048 *  or iterate over {@code FileSystems.getDefault().getFileStores()}
049 */
050@Deprecated
051public class FileSystemUtils {
052
053    /** Singleton instance, used mainly for testing. */
054    private static final FileSystemUtils INSTANCE = new FileSystemUtils();
055
056    /** Operating system state flag for error. */
057    private static final int INIT_PROBLEM = -1;
058    /** Operating system state flag for neither Unix nor Windows. */
059    private static final int OTHER = 0;
060    /** Operating system state flag for Windows. */
061    private static final int WINDOWS = 1;
062    /** Operating system state flag for Unix. */
063    private static final int UNIX = 2;
064    /** Operating system state flag for Posix flavour Unix. */
065    private static final int POSIX_UNIX = 3;
066
067    /** The operating system flag. */
068    private static final int OS;
069
070    /** The path to df */
071    private static final String DF;
072
073    static {
074        int os = OTHER;
075        String dfPath = "df";
076        try {
077            String osName = System.getProperty("os.name");
078            if (osName == null) {
079                throw new IOException("os.name not found");
080            }
081            osName = osName.toLowerCase(Locale.ENGLISH);
082            // match
083            if (osName.contains("windows")) {
084                os = WINDOWS;
085            } else if (osName.contains("linux") ||
086                    osName.contains("mpe/ix") ||
087                    osName.contains("freebsd") ||
088                    osName.contains("openbsd") ||
089                    osName.contains("irix") ||
090                    osName.contains("digital unix") ||
091                    osName.contains("unix") ||
092                    osName.contains("mac os x")) {
093                os = UNIX;
094            } else if (osName.contains("sun os") ||
095                    osName.contains("sunos") ||
096                    osName.contains("solaris")) {
097                os = POSIX_UNIX;
098                dfPath = "/usr/xpg4/bin/df";
099            } else if (osName.contains("hp-ux") ||
100                    osName.contains("aix")) {
101                os = POSIX_UNIX;
102            }
103
104        } catch (final Exception ex) {
105            os = INIT_PROBLEM;
106        }
107        OS = os;
108        DF = dfPath;
109    }
110
111    /**
112     * Returns the free space on a drive or volume by invoking
113     * the command line.
114     * This method does not normalize the result, and typically returns
115     * bytes on Windows, 512 byte units on OS X and kilobytes on Unix.
116     * As this is not very useful, this method is deprecated in favor
117     * of {@link #freeSpaceKb(String)} which returns a result in kilobytes.
118     * <p>
119     * Note that some OS's are NOT currently supported, including OS/390,
120     * OpenVMS.
121     * <pre>
122     * FileSystemUtils.freeSpace("C:");       // Windows
123     * FileSystemUtils.freeSpace("/volume");  // *nix
124     * </pre>
125     * The free space is calculated via the command line.
126     * It uses 'dir /-c' on Windows and 'df' on *nix.
127     *
128     * @param path  the path to get free space for, not null, not empty on Unix
129     * @return the amount of free drive space on the drive or volume
130     * @throws IllegalArgumentException if the path is invalid
131     * @throws IllegalStateException if an error occurred in initialization
132     * @throws IOException if an error occurs when finding the free space
133     * @since 1.1, enhanced OS support in 1.2 and 1.3
134     * @deprecated Use freeSpaceKb(String)
135     *  Deprecated from 1.3, may be removed in 2.0
136     */
137    @Deprecated
138    public static long freeSpace(final String path) throws IOException {
139        return INSTANCE.freeSpaceOS(path, OS, false, Duration.ofMillis(-1));
140    }
141
142    /**
143     * Returns the free space for the working directory
144     * in kibibytes (1024 bytes) by invoking the command line.
145     * <p>
146     * Identical to:
147     * <pre>
148     * freeSpaceKb(FileUtils.current().getAbsolutePath())
149     * </pre>
150     * @return the amount of free drive space on the drive or volume in kilobytes
151     * @throws IllegalStateException if an error occurred in initialization
152     * @throws IOException if an error occurs when finding the free space
153     * @since 2.0
154     * @deprecated As of 2.6 deprecated without replacement. Please use {@link java.nio.file.FileStore#getUsableSpace()}.
155     */
156    @Deprecated
157    public static long freeSpaceKb() throws IOException {
158        return freeSpaceKb(-1);
159    }
160
161    /**
162     * Returns the free space for the working directory
163     * in kibibytes (1024 bytes) by invoking the command line.
164     * <p>
165     * Identical to:
166     * <pre>
167     * freeSpaceKb(FileUtils.current().getAbsolutePath())
168     * </pre>
169     * @param timeout The timeout amount in milliseconds or no timeout if the value
170     *  is zero or less
171     * @return the amount of free drive space on the drive or volume in kilobytes
172     * @throws IllegalStateException if an error occurred in initialization
173     * @throws IOException if an error occurs when finding the free space
174     * @since 2.0
175     * @deprecated As of 2.6 deprecated without replacement. Please use {@link java.nio.file.FileStore#getUsableSpace()}.
176     */
177    @Deprecated
178    public static long freeSpaceKb(final long timeout) throws IOException {
179        return freeSpaceKb(FileUtils.current().getAbsolutePath(), timeout);
180    }
181    /**
182     * Returns the free space on a drive or volume in kibibytes (1024 bytes)
183     * by invoking the command line.
184     * <pre>
185     * FileSystemUtils.freeSpaceKb("C:");       // Windows
186     * FileSystemUtils.freeSpaceKb("/volume");  // *nix
187     * </pre>
188     * The free space is calculated via the command line.
189     * It uses 'dir /-c' on Windows, 'df -kP' on AIX/HP-UX and 'df -k' on other Unix.
190     * <p>
191     * In order to work, you must be running Windows, or have an implementation of
192     * Unix df that supports GNU format when passed -k (or -kP). If you are going
193     * to rely on this code, please check that it works on your OS by running
194     * some simple tests to compare the command line with the output from this class.
195     * If your operating system isn't supported, please raise a JIRA call detailing
196     * the exact result from df -k and as much other detail as possible, thanks.
197     *
198     * @param path  the path to get free space for, not null, not empty on Unix
199     * @return the amount of free drive space on the drive or volume in kilobytes
200     * @throws IllegalArgumentException if the path is invalid
201     * @throws IllegalStateException if an error occurred in initialization
202     * @throws IOException if an error occurs when finding the free space
203     * @since 1.2, enhanced OS support in 1.3
204     * @deprecated As of 2.6 deprecated without replacement. Please use {@link java.nio.file.FileStore#getUsableSpace()}.
205     */
206    @Deprecated
207    public static long freeSpaceKb(final String path) throws IOException {
208        return freeSpaceKb(path, -1);
209    }
210
211    /**
212     * Returns the free space on a drive or volume in kibibytes (1024 bytes)
213     * by invoking the command line.
214     * <pre>
215     * FileSystemUtils.freeSpaceKb("C:");       // Windows
216     * FileSystemUtils.freeSpaceKb("/volume");  // *nix
217     * </pre>
218     * The free space is calculated via the command line.
219     * It uses 'dir /-c' on Windows, 'df -kP' on AIX/HP-UX and 'df -k' on other Unix.
220     * <p>
221     * In order to work, you must be running Windows, or have an implementation of
222     * Unix df that supports GNU format when passed -k (or -kP). If you are going
223     * to rely on this code, please check that it works on your OS by running
224     * some simple tests to compare the command line with the output from this class.
225     * If your operating system isn't supported, please raise a JIRA call detailing
226     * the exact result from df -k and as much other detail as possible, thanks.
227     *
228     * @param path  the path to get free space for, not null, not empty on Unix
229     * @param timeout The timeout amount in milliseconds or no timeout if the value
230     *  is zero or less
231     * @return the amount of free drive space on the drive or volume in kilobytes
232     * @throws IllegalArgumentException if the path is invalid
233     * @throws IllegalStateException if an error occurred in initialization
234     * @throws IOException if an error occurs when finding the free space
235     * @since 2.0
236     * @deprecated As of 2.6 deprecated without replacement. Please use {@link java.nio.file.FileStore#getUsableSpace()}.
237     */
238    @Deprecated
239    public static long freeSpaceKb(final String path, final long timeout) throws IOException {
240        return INSTANCE.freeSpaceOS(path, OS, true, Duration.ofMillis(timeout));
241    }
242
243    /**
244     * Instances should NOT be constructed in standard programming.
245     */
246    public FileSystemUtils() {
247    }
248
249    /**
250     * Returns the free space on a drive or volume in a cross-platform manner.
251     * Note that some OS's are NOT currently supported, including OS/390.
252     * <pre>
253     * FileSystemUtils.freeSpace("C:");  // Windows
254     * FileSystemUtils.freeSpace("/volume");  // *nix
255     * </pre>
256     * The free space is calculated via the command line.
257     * It uses 'dir /-c' on Windows and 'df' on *nix.
258     *
259     * @param path  the path to get free space for, not null, not empty on Unix
260     * @param os  the operating system code
261     * @param kb  whether to normalize to kilobytes
262     * @param timeout The timeout amount in milliseconds or no timeout if the value
263     *  is zero or less
264     * @return the amount of free drive space on the drive or volume
265     * @throws IllegalArgumentException if the path is invalid
266     * @throws IllegalStateException if an error occurred in initialization
267     * @throws IOException if an error occurs when finding the free space
268     */
269    long freeSpaceOS(final String path, final int os, final boolean kb, final Duration timeout) throws IOException {
270        Objects.requireNonNull(path, "path");
271        switch (os) {
272        case WINDOWS:
273            return kb ? freeSpaceWindows(path, timeout) / FileUtils.ONE_KB : freeSpaceWindows(path, timeout);
274        case UNIX:
275            return freeSpaceUnix(path, kb, false, timeout);
276        case POSIX_UNIX:
277            return freeSpaceUnix(path, kb, true, timeout);
278        case OTHER:
279            throw new IllegalStateException("Unsupported operating system");
280        default:
281            throw new IllegalStateException("Exception caught when determining operating system");
282        }
283    }
284
285    /**
286     * Find free space on the *nix platform using the 'df' command.
287     *
288     * @param path  the path to get free space for
289     * @param kb  whether to normalize to kilobytes
290     * @param posix  whether to use the POSIX standard format flag
291     * @param timeout The timeout amount in milliseconds or no timeout if the value
292     *  is zero or less
293     * @return the amount of free drive space on the volume
294     * @throws IOException If an I/O error occurs
295     */
296    long freeSpaceUnix(final String path, final boolean kb, final boolean posix, final Duration timeout)
297            throws IOException {
298        if (path.isEmpty()) {
299            throw new IllegalArgumentException("Path must not be empty");
300        }
301
302        // build and run the 'dir' command
303        String flags = "-";
304        if (kb) {
305            flags += "k";
306        }
307        if (posix) {
308            flags += "P";
309        }
310        final String[] cmdAttribs = flags.length() > 1 ? new String[] { DF, flags, path } : new String[] { DF, path };
311
312        // perform the command, asking for up to 3 lines (header, interesting, overflow)
313        final List<String> lines = performCommand(cmdAttribs, 3, timeout);
314        if (lines.size() < 2) {
315            // unknown problem, throw exception
316            throw new IOException("Command line '" + DF + "' did not return info as expected for path '" + path + "'- response was " + lines);
317        }
318        final String line2 = lines.get(1); // the line we're interested in
319
320        // Now, we tokenize the string. The fourth element is what we want.
321        StringTokenizer tok = new StringTokenizer(line2, " ");
322        if (tok.countTokens() < 4) {
323            // could be long Filesystem, thus data on third line
324            if (tok.countTokens() != 1 || lines.size() < 3) {
325                throw new IOException("Command line '" + DF + "' did not return data as expected for path '" + path + "'- check path is valid");
326            }
327            final String line3 = lines.get(2); // the line may be interested in
328            tok = new StringTokenizer(line3, " ");
329        } else {
330            tok.nextToken(); // Ignore Filesystem
331        }
332        tok.nextToken(); // Ignore 1K-blocks
333        tok.nextToken(); // Ignore Used
334        final String freeSpace = tok.nextToken();
335        return parseBytes(freeSpace, path);
336    }
337
338    /**
339     * Find free space on the Windows platform using the 'dir' command.
340     *
341     * @param path  the path to get free space for, including the colon
342     * @param timeout The timeout amount in milliseconds or no timeout if the value
343     *  is zero or less
344     * @return the amount of free drive space on the drive
345     * @throws IOException If an I/O error occurs
346     */
347    long freeSpaceWindows(final String path, final Duration timeout) throws IOException {
348        String normPath = FilenameUtils.normalize(path, false);
349        if (normPath == null) {
350            throw new IllegalArgumentException(path);
351        }
352        if (!normPath.isEmpty() && normPath.charAt(0) != '"') {
353            normPath = "\"" + normPath + "\"";
354        }
355
356        // build and run the 'dir' command
357        final String[] cmdAttribs = { "cmd.exe", "/C", "dir /a /-c " + normPath };
358
359        // read in the output of the command to an ArrayList
360        final List<String> lines = performCommand(cmdAttribs, Integer.MAX_VALUE, timeout);
361
362        // now iterate over the lines we just read and find the LAST
363        // non-empty line (the free space bytes should be in the last element
364        // of the ArrayList anyway, but this will ensure it works even if it's
365        // not, still assuming it is on the last non-blank line)
366        for (int i = lines.size() - 1; i >= 0; i--) {
367            final String line = lines.get(i);
368            if (!line.isEmpty()) {
369                return parseDir(line, normPath);
370            }
371        }
372        // all lines are blank
373        throw new IOException("Command line 'dir /-c' did not return any info for path '" + normPath + "'");
374    }
375
376    /**
377     * Opens the process to the operating system.
378     *
379     * @param cmdAttribs  the command line parameters
380     * @return the process
381     * @throws IOException If an I/O error occurs
382     */
383    Process openProcess(final String[] cmdAttribs) throws IOException {
384        return Runtime.getRuntime().exec(cmdAttribs);
385    }
386
387    /**
388     * Parses the bytes from a string.
389     *
390     * @param freeSpace  the free space string
391     * @param path  the path
392     * @return the number of bytes
393     * @throws IOException If an I/O error occurs
394     */
395    long parseBytes(final String freeSpace, final String path) throws IOException {
396        try {
397            final long bytes = Long.parseLong(freeSpace);
398            if (bytes < 0) {
399                throw new IOException("Command line '" + DF + "' did not find free space in response for path '" + path + "'- check path is valid");
400            }
401            return bytes;
402
403        } catch (final NumberFormatException ex) {
404            throw new IOException("Command line '" + DF + "' did not return numeric data as expected for path '" + path + "'- check path is valid", ex);
405        }
406    }
407
408    /**
409     * Parses the Windows dir response last line
410     *
411     * @param line  the line to parse
412     * @param path  the path that was sent
413     * @return the number of bytes
414     * @throws IOException If an I/O error occurs
415     */
416    long parseDir(final String line, final String path) throws IOException {
417        // read from the end of the line to find the last numeric
418        // character on the line, then continue until we find the first
419        // non-numeric character, and everything between that and the last
420        // numeric character inclusive is our free space bytes count
421        int bytesStart = 0;
422        int bytesEnd = 0;
423        int j = line.length() - 1;
424        innerLoop1: while (j >= 0) {
425            final char c = line.charAt(j);
426            if (Character.isDigit(c)) {
427                // found the last numeric character, this is the end of
428                // the free space bytes count
429                bytesEnd = j + 1;
430                break innerLoop1;
431            }
432            j--;
433        }
434        innerLoop2: while (j >= 0) {
435            final char c = line.charAt(j);
436            if (!Character.isDigit(c) && c != ',' && c != '.') {
437                // found the next non-numeric character, this is the
438                // beginning of the free space bytes count
439                bytesStart = j + 1;
440                break innerLoop2;
441            }
442            j--;
443        }
444        if (j < 0) {
445            throw new IOException("Command line 'dir /-c' did not return valid info for path '" + path + "'");
446        }
447
448        // remove commas and dots in the bytes count
449        final StringBuilder buf = new StringBuilder(line.substring(bytesStart, bytesEnd));
450        for (int k = 0; k < buf.length(); k++) {
451            if (buf.charAt(k) == ',' || buf.charAt(k) == '.') {
452                buf.deleteCharAt(k--);
453            }
454        }
455        return parseBytes(buf.toString(), path);
456    }
457
458    /**
459     * Performs an OS command.
460     *
461     * @param cmdAttribs  the command line parameters
462     * @param max The maximum limit for the lines returned
463     * @param timeout The timeout amount in milliseconds or no timeout if the value
464     *  is zero or less
465     * @return the lines returned by the command, converted to lower-case
466     * @throws IOException if an error occurs
467     */
468    List<String> performCommand(final String[] cmdAttribs, final int max, final Duration timeout) throws IOException {
469        //
470        // This method does what it can to avoid the 'Too many open files' error
471        // based on trial and error and these links:
472        // http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4784692
473        // http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4801027
474        // http://forum.java.sun.com/thread.jspa?threadID=533029&messageID=2572018
475        // however, it's still not perfect as the JDK support is so poor
476        // (see commons-exec or Ant for a better multithreaded multi-OS solution)
477        //
478        final Process proc = openProcess(cmdAttribs);
479        final Thread monitor = ThreadMonitor.start(timeout);
480        try (InputStream in = proc.getInputStream();
481                OutputStream out = proc.getOutputStream();
482                // default Charset is most likely appropriate here
483                InputStream err = proc.getErrorStream();
484                // If in is null here, InputStreamReader throws NullPointerException
485                BufferedReader inr = new BufferedReader(new InputStreamReader(in, Charset.defaultCharset()))) {
486
487            final List<String> lines = inr.lines().limit(max).map(line -> line.toLowerCase(Locale.getDefault()).trim()).collect(Collectors.toList());
488            proc.waitFor();
489            ThreadMonitor.stop(monitor);
490
491            if (proc.exitValue() != 0) {
492                // Command problem, throw exception
493                throw new IOException("Command line returned OS error code '" + proc.exitValue() + "' for command " + Arrays.asList(cmdAttribs));
494            }
495            if (lines.isEmpty()) {
496                // Unknown problem, throw exception
497                throw new IOException("Command line did not return any info for command " + Arrays.asList(cmdAttribs));
498            }
499
500            return lines;
501
502        } catch (final InterruptedException ex) {
503            throw new IOException("Command line threw an InterruptedException for command " + Arrays.asList(cmdAttribs) + " timeout=" + timeout, ex);
504        } finally {
505            if (proc != null) {
506                proc.destroy();
507            }
508        }
509    }
510
511}