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/*
* Copyright 2016-2022 The OSHI Project Contributors
* SPDX-License-Identifier: MIT
*/
package oshi.util;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.sun.jna.Native;
import com.sun.jna.NativeLong;
import com.sun.jna.Pointer;
import com.sun.jna.platform.unix.LibCAPI.size_t;
import oshi.annotation.concurrent.ThreadSafe;
/**
* File reading methods
*/
@ThreadSafe
public final class FileUtil {
private static final Logger LOG = LoggerFactory.getLogger(FileUtil.class);
private static final String READING_LOG = "Reading file {}";
private static final String READ_LOG = "Read {}";
private FileUtil() {
}
/**
* Read an entire file at one time. Intended primarily for Linux /proc filesystem to avoid recalculating file
* contents on iterative reads.
*
* @param filename The file to read
* @return A list of Strings representing each line of the file, or an empty list if file could not be read or is
* empty
*/
public static List readFile(String filename) {
return readFile(filename, true);
}
/**
* Read an entire file at one time. Intended primarily for Linux /proc filesystem to avoid recalculating file
* contents on iterative reads.
*
* @param filename The file to read
* @param reportError Whether to log errors reading the file
* @return A list of Strings representing each line of the file, or an empty list if file could not be read or is
* empty
*/
public static List readFile(String filename, boolean reportError) {
if (new File(filename).canRead()) {
if (LOG.isDebugEnabled()) {
LOG.debug(READING_LOG, filename);
}
try {
return Files.readAllLines(Paths.get(filename), StandardCharsets.UTF_8);
} catch (IOException e) {
if (reportError) {
LOG.error("Error reading file {}. {}", filename, e.getMessage());
} else {
LOG.debug("Error reading file {}. {}", filename, e.getMessage());
}
}
} else if (reportError) {
LOG.warn("File not found or not readable: {}", filename);
}
return new ArrayList<>();
}
/**
* Read an entire file at one time. Intended primarily for Linux /proc filesystem to avoid recalculating file
* contents on iterative reads.
*
* @param filename The file to read
* @return A byte array representing the file
*/
public static byte[] readAllBytes(String filename) {
return readAllBytes(filename, true);
}
/**
* Read an entire file at one time. Intended primarily for Linux /proc filesystem to avoid recalculating file
* contents on iterative reads.
*
* @param filename The file to read
* @param reportError Whether to log errors reading the file
* @return A byte array representing the file
*/
public static byte[] readAllBytes(String filename, boolean reportError) {
if (new File(filename).canRead()) {
if (LOG.isDebugEnabled()) {
LOG.debug(READING_LOG, filename);
}
try {
return Files.readAllBytes(Paths.get(filename));
} catch (IOException e) {
if (reportError) {
LOG.error("Error reading file {}. {}", filename, e.getMessage());
} else {
LOG.debug("Error reading file {}. {}", filename, e.getMessage());
}
}
} else if (reportError) {
LOG.warn("File not found or not readable: {}", filename);
}
return new byte[0];
}
/**
* Read an entire file at one time. Intended for unix /proc binary files to avoid reading file contents on iterative
* reads.
*
*
* @param filename The file to read
* @return A bytebuffer representing the file if read was successful; null otherwise
*/
public static ByteBuffer readAllBytesAsBuffer(String filename) {
byte[] bytes = readAllBytes(filename, false);
ByteBuffer buff = ByteBuffer.allocate(bytes.length);
buff.order(ByteOrder.nativeOrder());
for (byte b : bytes) {
buff.put(b);
}
buff.flip();
return buff;
}
/**
* Reads a byte value from a ByteBuffer
*
* @param buff The bytebuffer to read from
* @return The next byte value
*/
public static byte readByteFromBuffer(ByteBuffer buff) {
if (buff.position() < buff.limit()) {
return buff.get();
}
return 0;
}
/**
* Reads a short value from a ByteBuffer
*
* @param buff The bytebuffer to read from
* @return The next short value
*/
public static short readShortFromBuffer(ByteBuffer buff) {
if (buff.position() <= buff.limit() - 2) {
return buff.getShort();
}
return 0;
}
/**
* Reads an int value from a ByteBuffer
*
* @param buff The bytebuffer to read from
* @return The next int value
*/
public static int readIntFromBuffer(ByteBuffer buff) {
if (buff.position() <= buff.limit() - 4) {
return buff.getInt();
}
return 0;
}
/**
* Reads a long value from a ByteBuffer
*
* @param buff The bytebuffer to read from
* @return The next long value
*/
public static long readLongFromBuffer(ByteBuffer buff) {
if (buff.position() <= buff.limit() - 8) {
return buff.getLong();
}
return 0L;
}
/**
* Reads a NativeLong value from a ByteBuffer
*
* @param buff The bytebuffer to read from
* @return The next value
*/
public static NativeLong readNativeLongFromBuffer(ByteBuffer buff) {
return new NativeLong(Native.LONG_SIZE == 4 ? readIntFromBuffer(buff) : readLongFromBuffer(buff));
}
/**
* Reads a size_t value from a ByteBuffer
*
* @param buff The bytebuffer to read from
* @return The next value
*/
public static size_t readSizeTFromBuffer(ByteBuffer buff) {
return new size_t(Native.SIZE_T_SIZE == 4 ? readIntFromBuffer(buff) : readLongFromBuffer(buff));
}
/**
* Reads a byte array value from a ByteBuffer
*
* @param buff The bytebuffer to read from
* @param array The array into which to read the data
*/
public static void readByteArrayFromBuffer(ByteBuffer buff, byte[] array) {
if (buff.position() <= buff.limit() - array.length) {
buff.get(array);
}
}
/**
* Reads a Pointer value from a ByteBuffer
*
* @param buff The bytebuffer to read from
* @return The next value
*/
public static Pointer readPointerFromBuffer(ByteBuffer buff) {
if (buff.position() <= buff.limit() - Native.POINTER_SIZE) {
return Native.POINTER_SIZE == 4 ? new Pointer(buff.getInt()) : new Pointer(buff.getLong());
}
return Pointer.NULL;
}
/**
* Read a file and return the long value contained therein. Intended primarily for Linux /sys filesystem
*
* @param filename The file to read
* @return The value contained in the file, if any; otherwise zero
*/
public static long getLongFromFile(String filename) {
if (LOG.isDebugEnabled()) {
LOG.debug(READING_LOG, filename);
}
List read = FileUtil.readFile(filename, false);
if (!read.isEmpty()) {
if (LOG.isTraceEnabled()) {
LOG.trace(READ_LOG, read.get(0));
}
return ParseUtil.parseLongOrDefault(read.get(0), 0L);
}
return 0L;
}
/**
* Read a file and return the unsigned long value contained therein as a long. Intended primarily for Linux /sys
* filesystem
*
* @param filename The file to read
* @return The value contained in the file, if any; otherwise zero
*/
public static long getUnsignedLongFromFile(String filename) {
if (LOG.isDebugEnabled()) {
LOG.debug(READING_LOG, filename);
}
List read = FileUtil.readFile(filename, false);
if (!read.isEmpty()) {
if (LOG.isTraceEnabled()) {
LOG.trace(READ_LOG, read.get(0));
}
return ParseUtil.parseUnsignedLongOrDefault(read.get(0), 0L);
}
return 0L;
}
/**
* Read a file and return the int value contained therein. Intended primarily for Linux /sys filesystem
*
* @param filename The file to read
* @return The value contained in the file, if any; otherwise zero
*/
public static int getIntFromFile(String filename) {
if (LOG.isDebugEnabled()) {
LOG.debug(READING_LOG, filename);
}
try {
List read = FileUtil.readFile(filename, false);
if (!read.isEmpty()) {
if (LOG.isTraceEnabled()) {
LOG.trace(READ_LOG, read.get(0));
}
return Integer.parseInt(read.get(0));
}
} catch (NumberFormatException ex) {
LOG.warn("Unable to read value from {}. {}", filename, ex.getMessage());
}
return 0;
}
/**
* Read a file and return the String value contained therein. Intended primarily for Linux /sys filesystem
*
* @param filename The file to read
* @return The value contained in the file, if any; otherwise empty string
*/
public static String getStringFromFile(String filename) {
if (LOG.isDebugEnabled()) {
LOG.debug(READING_LOG, filename);
}
List read = FileUtil.readFile(filename, false);
if (!read.isEmpty()) {
if (LOG.isTraceEnabled()) {
LOG.trace(READ_LOG, read.get(0));
}
return read.get(0);
}
return "";
}
/**
* Read a file and return a map of string keys to string values contained therein. Intended primarily for Linux
* {@code /proc/[pid]} files to provide more detailed or accurate information not available in the API.
*
* @param filename The file to read
* @param separator Character(s) in each line of the file that separate the key and the value.
*
* @return The map contained in the file, delimited by the separator, with the value whitespace trimmed. If keys and
* values are not parsed, an empty map is returned.
*/
public static Map getKeyValueMapFromFile(String filename, String separator) {
Map map = new HashMap<>();
if (LOG.isDebugEnabled()) {
LOG.debug(READING_LOG, filename);
}
List lines = FileUtil.readFile(filename, false);
for (String line : lines) {
String[] parts = line.split(separator);
if (parts.length == 2) {
map.put(parts[0], parts[1].trim());
}
}
return map;
}
/**
* Read a configuration file from the sequence of context classloader, system classloader and classloader of the
* current class, and return its properties
*
* @param propsFilename The filename
* @return A {@link Properties} object containing the properties.
*/
public static Properties readPropertiesFromFilename(String propsFilename) {
Properties archProps = new Properties();
// Load the configuration file from at least one of multiple possible
// ClassLoaders, evaluated in order, eliminating duplicates
for (ClassLoader loader : Stream.of(Thread.currentThread().getContextClassLoader(),
ClassLoader.getSystemClassLoader(), FileUtil.class.getClassLoader())
.collect(Collectors.toCollection(LinkedHashSet::new))) {
if (readPropertiesFromClassLoader(propsFilename, archProps, loader)) {
return archProps;
}
}
LOG.warn("Failed to load configuration file from classloader: {}", propsFilename);
return archProps;
}
private static boolean readPropertiesFromClassLoader(String propsFilename, Properties archProps,
ClassLoader loader) {
if (loader == null) {
return false;
}
// Load the configuration file from the classLoader
try {
List resources = Collections.list(loader.getResources(propsFilename));
if (resources.isEmpty()) {
LOG.debug("No {} file found from ClassLoader {}", propsFilename, loader);
return false;
}
if (resources.size() > 1) {
LOG.warn("Configuration conflict: there is more than one {} file on the classpath: {}", propsFilename,
resources);
}
try (InputStream in = resources.get(0).openStream()) {
if (in != null) {
archProps.load(in);
}
}
return true;
} catch (IOException e) {
return false;
}
}
/**
* Reads the target of a symbolic link
*
* @param file The file to read
* @return The symlink name, or null if the read failed
*/
public static String readSymlinkTarget(File file) {
try {
return Files.readSymbolicLink(Paths.get(file.getAbsolutePath())).toString();
} catch (IOException e) {
return null;
}
}
}