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     */
017    package org.apache.commons.io;
018    
019    import java.io.BufferedReader;
020    import java.io.IOException;
021    import java.io.InputStream;
022    import java.io.InputStreamReader;
023    import java.io.OutputStream;
024    import java.util.ArrayList;
025    import java.util.Arrays;
026    import java.util.List;
027    import java.util.StringTokenizer;
028    
029    /**
030     * General File System utilities.
031     * <p>
032     * This class provides static utility methods for general file system
033     * functions not provided via the JDK {@link java.io.File File} class.
034     * <p>
035     * The current functions provided are:
036     * <ul>
037     * <li>Get the free space on a drive
038     * </ul>
039     *
040     * @author Frank W. Zammetti
041     * @author Stephen Colebourne
042     * @author Thomas Ledoux
043     * @author James Urie
044     * @author Magnus Grimsell
045     * @author Thomas Ledoux
046     * @version $Id: FileSystemUtils.java 453889 2006-10-07 11:56:25Z scolebourne $
047     * @since Commons IO 1.1
048     */
049    public class FileSystemUtils {
050    
051        /** Singleton instance, used mainly for testing. */
052        private static final FileSystemUtils INSTANCE = new FileSystemUtils();
053    
054        /** Operating system state flag for error. */
055        private static final int INIT_PROBLEM = -1;
056        /** Operating system state flag for neither Unix nor Windows. */
057        private static final int OTHER = 0;
058        /** Operating system state flag for Windows. */
059        private static final int WINDOWS = 1;
060        /** Operating system state flag for Unix. */
061        private static final int UNIX = 2;
062        /** Operating system state flag for Posix flavour Unix. */
063        private static final int POSIX_UNIX = 3;
064    
065        /** The operating system flag. */
066        private static final int OS;
067        static {
068            int os = OTHER;
069            try {
070                String osName = System.getProperty("os.name");
071                if (osName == null) {
072                    throw new IOException("os.name not found");
073                }
074                osName = osName.toLowerCase();
075                // match
076                if (osName.indexOf("windows") != -1) {
077                    os = WINDOWS;
078                } else if (osName.indexOf("linux") != -1 ||
079                    osName.indexOf("sun os") != -1 ||
080                    osName.indexOf("sunos") != -1 ||
081                    osName.indexOf("solaris") != -1 ||
082                    osName.indexOf("mpe/ix") != -1 ||
083                    osName.indexOf("freebsd") != -1 ||
084                    osName.indexOf("irix") != -1 ||
085                    osName.indexOf("digital unix") != -1 ||
086                    osName.indexOf("unix") != -1 ||
087                    osName.indexOf("mac os x") != -1) {
088                    os = UNIX;
089                } else if (osName.indexOf("hp-ux") != -1 ||
090                    osName.indexOf("aix") != -1) {
091                    os = POSIX_UNIX;
092                } else {
093                    os = OTHER;
094                }
095    
096            } catch (Exception ex) {
097                os = INIT_PROBLEM;
098            }
099            OS = os;
100        }
101    
102        /**
103         * Instances should NOT be constructed in standard programming.
104         */
105        public FileSystemUtils() {
106            super();
107        }
108    
109        //-----------------------------------------------------------------------
110        /**
111         * Returns the free space on a drive or volume by invoking
112         * the command line.
113         * This method does not normalize the result, and typically returns
114         * bytes on Windows, 512 byte units on OS X and kilobytes on Unix.
115         * As this is not very useful, this method is deprecated in favour
116         * of {@link #freeSpaceKb(String)} which returns a result in kilobytes.
117         * <p>
118         * Note that some OS's are NOT currently supported, including OS/390,
119         * OpenVMS and and SunOS 5. (SunOS is supported by <code>freeSpaceKb</code>.)
120         * <pre>
121         * FileSystemUtils.freeSpace("C:");       // Windows
122         * FileSystemUtils.freeSpace("/volume");  // *nix
123         * </pre>
124         * The free space is calculated via the command line.
125         * It uses 'dir /-c' on Windows and 'df' on *nix.
126         *
127         * @param path  the path to get free space for, not null, not empty on Unix
128         * @return the amount of free drive space on the drive or volume
129         * @throws IllegalArgumentException if the path is invalid
130         * @throws IllegalStateException if an error occurred in initialisation
131         * @throws IOException if an error occurs when finding the free space
132         * @since Commons IO 1.1, enhanced OS support in 1.2 and 1.3
133         * @deprecated Use freeSpaceKb(String)
134         *  Deprecated from 1.3, may be removed in 2.0
135         */
136        public static long freeSpace(String path) throws IOException {
137            return INSTANCE.freeSpaceOS(path, OS, false);
138        }
139    
140        //-----------------------------------------------------------------------
141        /**
142         * Returns the free space on a drive or volume in kilobytes by invoking
143         * the command line.
144         * <pre>
145         * FileSystemUtils.freeSpaceKb("C:");       // Windows
146         * FileSystemUtils.freeSpaceKb("/volume");  // *nix
147         * </pre>
148         * The free space is calculated via the command line.
149         * It uses 'dir /-c' on Windows, 'df -kP' on AIX/HP-UX and 'df -k' on other Unix.
150         * <p>
151         * In order to work, you must be running Windows, or have a implementation of
152         * Unix df that supports GNU format when passed -k (or -kP). If you are going
153         * to rely on this code, please check that it works on your OS by running
154         * some simple tests to compare the command line with the output from this class.
155         * If your operating system isn't supported, please raise a JIRA call detailing
156         * the exact result from df -k and as much other detail as possible, thanks.
157         *
158         * @param path  the path to get free space for, not null, not empty on Unix
159         * @return the amount of free drive space on the drive or volume in kilobytes
160         * @throws IllegalArgumentException if the path is invalid
161         * @throws IllegalStateException if an error occurred in initialisation
162         * @throws IOException if an error occurs when finding the free space
163         * @since Commons IO 1.2, enhanced OS support in 1.3
164         */
165        public static long freeSpaceKb(String path) throws IOException {
166            return INSTANCE.freeSpaceOS(path, OS, true);
167        }
168    
169        //-----------------------------------------------------------------------
170        /**
171         * Returns the free space on a drive or volume in a cross-platform manner.
172         * Note that some OS's are NOT currently supported, including OS/390.
173         * <pre>
174         * FileSystemUtils.freeSpace("C:");  // Windows
175         * FileSystemUtils.freeSpace("/volume");  // *nix
176         * </pre>
177         * The free space is calculated via the command line.
178         * It uses 'dir /-c' on Windows and 'df' on *nix.
179         *
180         * @param path  the path to get free space for, not null, not empty on Unix
181         * @param os  the operating system code
182         * @param kb  whether to normalize to kilobytes
183         * @return the amount of free drive space on the drive or volume
184         * @throws IllegalArgumentException if the path is invalid
185         * @throws IllegalStateException if an error occurred in initialisation
186         * @throws IOException if an error occurs when finding the free space
187         */
188        long freeSpaceOS(String path, int os, boolean kb) throws IOException {
189            if (path == null) {
190                throw new IllegalArgumentException("Path must not be empty");
191            }
192            switch (os) {
193                case WINDOWS:
194                    return (kb ? freeSpaceWindows(path) / 1024 : freeSpaceWindows(path));
195                case UNIX:
196                    return freeSpaceUnix(path, kb, false);
197                case POSIX_UNIX:
198                    return freeSpaceUnix(path, kb, true);
199                case OTHER:
200                    throw new IllegalStateException("Unsupported operating system");
201                default:
202                    throw new IllegalStateException(
203                      "Exception caught when determining operating system");
204            }
205        }
206    
207        //-----------------------------------------------------------------------
208        /**
209         * Find free space on the Windows platform using the 'dir' command.
210         *
211         * @param path  the path to get free space for, including the colon
212         * @return the amount of free drive space on the drive
213         * @throws IOException if an error occurs
214         */
215        long freeSpaceWindows(String path) throws IOException {
216            path = FilenameUtils.normalize(path);
217            if (path.length() > 2 && path.charAt(1) == ':') {
218                path = path.substring(0, 2);  // seems to make it work
219            }
220            
221            // build and run the 'dir' command
222            String[] cmdAttribs = new String[] {"cmd.exe", "/C", "dir /-c " + path};
223            
224            // read in the output of the command to an ArrayList
225            List lines = performCommand(cmdAttribs, Integer.MAX_VALUE);
226            
227            // now iterate over the lines we just read and find the LAST
228            // non-empty line (the free space bytes should be in the last element
229            // of the ArrayList anyway, but this will ensure it works even if it's
230            // not, still assuming it is on the last non-blank line)
231            for (int i = lines.size() - 1; i >= 0; i--) {
232                String line = (String) lines.get(i);
233                if (line.length() > 0) {
234                    return parseDir(line, path);
235                }
236            }
237            // all lines are blank
238            throw new IOException(
239                    "Command line 'dir /-c' did not return any info " +
240                    "for path '" + path + "'");
241        }
242    
243        /**
244         * Parses the Windows dir response last line
245         *
246         * @param line  the line to parse
247         * @param path  the path that was sent
248         * @return the number of bytes
249         * @throws IOException if an error occurs
250         */
251        long parseDir(String line, String path) throws IOException {
252            // read from the end of the line to find the last numeric
253            // character on the line, then continue until we find the first
254            // non-numeric character, and everything between that and the last
255            // numeric character inclusive is our free space bytes count
256            int bytesStart = 0;
257            int bytesEnd = 0;
258            int j = line.length() - 1;
259            innerLoop1: while (j >= 0) {
260                char c = line.charAt(j);
261                if (Character.isDigit(c)) {
262                  // found the last numeric character, this is the end of
263                  // the free space bytes count
264                  bytesEnd = j + 1;
265                  break innerLoop1;
266                }
267                j--;
268            }
269            innerLoop2: while (j >= 0) {
270                char c = line.charAt(j);
271                if (!Character.isDigit(c) && c != ',' && c != '.') {
272                  // found the next non-numeric character, this is the
273                  // beginning of the free space bytes count
274                  bytesStart = j + 1;
275                  break innerLoop2;
276                }
277                j--;
278            }
279            if (j < 0) {
280                throw new IOException(
281                        "Command line 'dir /-c' did not return valid info " +
282                        "for path '" + path + "'");
283            }
284            
285            // remove commas and dots in the bytes count
286            StringBuffer buf = new StringBuffer(line.substring(bytesStart, bytesEnd));
287            for (int k = 0; k < buf.length(); k++) {
288                if (buf.charAt(k) == ',' || buf.charAt(k) == '.') {
289                    buf.deleteCharAt(k--);
290                }
291            }
292            return parseBytes(buf.toString(), path);
293        }
294    
295        //-----------------------------------------------------------------------
296        /**
297         * Find free space on the *nix platform using the 'df' command.
298         *
299         * @param path  the path to get free space for
300         * @param kb  whether to normalize to kilobytes
301         * @param posix  whether to use the posix standard format flag
302         * @return the amount of free drive space on the volume
303         * @throws IOException if an error occurs
304         */
305        long freeSpaceUnix(String path, boolean kb, boolean posix) throws IOException {
306            if (path.length() == 0) {
307                throw new IllegalArgumentException("Path must not be empty");
308            }
309            path = FilenameUtils.normalize(path);
310    
311            // build and run the 'dir' command
312            String flags = "-";
313            if (kb) {
314                flags += "k";
315            }
316            if (posix) {
317                flags += "P";
318            }
319            String[] cmdAttribs = 
320                (flags.length() > 1 ? new String[] {"df", flags, path} : new String[] {"df", path});
321            
322            // perform the command, asking for up to 3 lines (header, interesting, overflow)
323            List lines = performCommand(cmdAttribs, 3);
324            if (lines.size() < 2) {
325                // unknown problem, throw exception
326                throw new IOException(
327                        "Command line 'df' did not return info as expected " +
328                        "for path '" + path + "'- response was " + lines);
329            }
330            String line2 = (String) lines.get(1); // the line we're interested in
331            
332            // Now, we tokenize the string. The fourth element is what we want.
333            StringTokenizer tok = new StringTokenizer(line2, " ");
334            if (tok.countTokens() < 4) {
335                // could be long Filesystem, thus data on third line
336                if (tok.countTokens() == 1 && lines.size() >= 3) {
337                    String line3 = (String) lines.get(2); // the line may be interested in
338                    tok = new StringTokenizer(line3, " ");
339                } else {
340                    throw new IOException(
341                            "Command line 'df' did not return data as expected " +
342                            "for path '" + path + "'- check path is valid");
343                }
344            } else {
345                tok.nextToken(); // Ignore Filesystem
346            }
347            tok.nextToken(); // Ignore 1K-blocks
348            tok.nextToken(); // Ignore Used
349            String freeSpace = tok.nextToken();
350            return parseBytes(freeSpace, path);
351        }
352    
353        //-----------------------------------------------------------------------
354        /**
355         * Parses the bytes from a string.
356         * 
357         * @param freeSpace  the free space string
358         * @param path  the path
359         * @return the number of bytes
360         * @throws IOException if an error occurs
361         */
362        long parseBytes(String freeSpace, String path) throws IOException {
363            try {
364                long bytes = Long.parseLong(freeSpace);
365                if (bytes < 0) {
366                    throw new IOException(
367                            "Command line 'df' did not find free space in response " +
368                            "for path '" + path + "'- check path is valid");
369                }
370                return bytes;
371                
372            } catch (NumberFormatException ex) {
373                throw new IOException(
374                        "Command line 'df' did not return numeric data as expected " +
375                        "for path '" + path + "'- check path is valid");
376            }
377        }
378    
379        //-----------------------------------------------------------------------
380        /**
381         * Performs the os command.
382         *
383         * @param cmdAttribs  the command line parameters
384         * @param max The maximum limit for the lines returned
385         * @return the parsed data
386         * @throws IOException if an error occurs
387         */
388        List performCommand(String[] cmdAttribs, int max) throws IOException {
389            // this method does what it can to avoid the 'Too many open files' error
390            // based on trial and error and these links:
391            // http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4784692
392            // http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4801027
393            // http://forum.java.sun.com/thread.jspa?threadID=533029&messageID=2572018
394            // however, its still not perfect as the JDK support is so poor
395            // (see commond-exec or ant for a better multi-threaded multi-os solution)
396            
397            List lines = new ArrayList(20);
398            Process proc = null;
399            InputStream in = null;
400            OutputStream out = null;
401            InputStream err = null;
402            BufferedReader inr = null;
403            try {
404                proc = openProcess(cmdAttribs);
405                in = proc.getInputStream();
406                out = proc.getOutputStream();
407                err = proc.getErrorStream();
408                inr = new BufferedReader(new InputStreamReader(in));
409                String line = inr.readLine();
410                while (line != null && lines.size() < max) {
411                    line = line.toLowerCase().trim();
412                    lines.add(line);
413                    line = inr.readLine();
414                }
415                
416                proc.waitFor();
417                if (proc.exitValue() != 0) {
418                    // os command problem, throw exception
419                    throw new IOException(
420                            "Command line returned OS error code '" + proc.exitValue() +
421                            "' for command " + Arrays.asList(cmdAttribs));
422                }
423                if (lines.size() == 0) {
424                    // unknown problem, throw exception
425                    throw new IOException(
426                            "Command line did not return any info " +
427                            "for command " + Arrays.asList(cmdAttribs));
428                }
429                return lines;
430                
431            } catch (InterruptedException ex) {
432                throw new IOException(
433                        "Command line threw an InterruptedException '" + ex.getMessage() +
434                        "' for command " + Arrays.asList(cmdAttribs));
435            } finally {
436                IOUtils.closeQuietly(in);
437                IOUtils.closeQuietly(out);
438                IOUtils.closeQuietly(err);
439                IOUtils.closeQuietly(inr);
440                if (proc != null) {
441                    proc.destroy();
442                }
443            }
444        }
445    
446        /**
447         * Opens the process to the operating system.
448         *
449         * @param cmdAttribs  the command line parameters
450         * @return the process
451         * @throws IOException if an error occurs
452         */
453        Process openProcess(String[] cmdAttribs) throws IOException {
454            return Runtime.getRuntime().exec(cmdAttribs);
455        }
456    
457    }