/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.sshd.common.util;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.atomic.AtomicReference;
/**
* Operating system dependent utility methods.
*
* @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
*/
public final class OsUtils {
/**
* Property that can be used to override the reported value from {@link #getCurrentUser()}.
* If not set then "user.name" system property is used
*/
public static final String CURRENT_USER_OVERRIDE_PROP = "org.apache.sshd.currentUser";
/**
* Property that can be used to override the reported value from {@link #getJavaVersion()}.
* If not set then "java.version" system property is used
*/
public static final String JAVA_VERSION_OVERRIDE_PROP = "org.apache.sshd.javaVersion";
/**
* Property that can be used to override the reported value from {@link #isWin32()}.
* If not set then "os.name" system property is used
*/
public static final String OS_TYPE_OVERRIDE_PROP = "org.apache.sshd.osType";
public static final String WINDOWS_SHELL_COMMAND_NAME = "cmd.exe";
public static final String LINUX_SHELL_COMMAND_NAME = "/bin/sh";
public static final String ROOT_USER = "root";
public static final List<String> LINUX_COMMAND =
Collections.unmodifiableList(Arrays.asList(LINUX_SHELL_COMMAND_NAME, "-i", "-l"));
public static final List<String> WINDOWS_COMMAND =
Collections.unmodifiableList(Collections.singletonList(WINDOWS_SHELL_COMMAND_NAME));
private static final AtomicReference<String> CURRENT_USER_HOLDER = new AtomicReference<>(null);
private static final AtomicReference<VersionInfo> JAVA_VERSION_HOLDER = new AtomicReference<>(null);
private static final AtomicReference<Boolean> OS_TYPE_HOLDER = new AtomicReference<>(null);
private OsUtils() {
throw new UnsupportedOperationException("No instance allowed");
}
/**
* @return true if the host is a UNIX system (and not Windows).
*/
public static boolean isUNIX() {
return !isWin32();
}
/**
* @return true if the host is Windows (and not UNIX).
* @see #OS_TYPE_OVERRIDE_PROP
* @see #setWin32(Boolean)
*/
public static boolean isWin32() {
Boolean typeValue;
synchronized (OS_TYPE_HOLDER) {
typeValue = OS_TYPE_HOLDER.get();
if (typeValue != null) { // is it the 1st time
return typeValue;
}
String value = System.getProperty(OS_TYPE_OVERRIDE_PROP, System.getProperty("os.name"));
typeValue = GenericUtils.trimToEmpty(value).toLowerCase().contains("windows");
OS_TYPE_HOLDER.set(typeValue);
}
return typeValue;
}
/**
* Can be used to enforce Win32 or Linux report from {@link #isWin32()} or {@link #isUNIX()}
* @param win32 The value to set - if {@code null} then O/S type is auto-detected
* @see #isWin32()
*/
public static void setWin32(Boolean win32) {
synchronized (OS_TYPE_HOLDER) {
OS_TYPE_HOLDER.set(win32);
}
}
public static List<String> resolveDefaultInteractiveCommand() {
return resolveInteractiveCommand(isWin32());
}
public static List<String> resolveInteractiveCommand(boolean isWin32) {
if (isWin32) {
return WINDOWS_COMMAND;
} else {
return LINUX_COMMAND;
}
}
/**
* Get current user name
*
* @return Current user
* @see #CURRENT_USER_OVERRIDE_PROP
*/
public static String getCurrentUser() {
String username = null;
synchronized (CURRENT_USER_HOLDER) {
username = CURRENT_USER_HOLDER.get();
if (username != null) { // have we already resolved it ?
return username;
}
username = getCanonicalUser(System.getProperty(CURRENT_USER_OVERRIDE_PROP, System.getProperty("user.name")));
ValidateUtils.checkNotNullAndNotEmpty(username, "No username available");
CURRENT_USER_HOLDER.set(username);
}
return username;
}
/**
* Remove {@code Windows} domain and/or group prefix as well as "(User);" suffix
*
* @param user The original username - ignored if {@code null}/empty
* @return The canonical user - unchanged if {@code Unix} O/S
*/
public static String getCanonicalUser(String user) {
if (GenericUtils.isEmpty(user)) {
return user;
}
// Windows owner sometime has the domain and/or group prepended to it
if (isWin32()) {
int pos = user.lastIndexOf('\\');
if (pos > 0) {
user = user.substring(pos + 1);
}
pos = user.indexOf(' ');
if (pos > 0) {
user = user.substring(0, pos).trim();
}
}
return user;
}
/**
* Attempts to resolve canonical group name for {@code Windows}
*
* @param group The original group name - used if not {@code null}/empty
* @param user The owner name - sometimes it contains a group name
* @return The canonical group name
*/
public static String resolveCanonicalGroup(String group, String user) {
if (isUNIX()) {
return group;
}
// we reach this code only for Windows
if (GenericUtils.isEmpty(group)) {
int pos = GenericUtils.isEmpty(user) ? -1 : user.lastIndexOf('\\');
return (pos > 0) ? user.substring(0, pos) : group;
}
int pos = group.indexOf(' ');
return (pos < 0) ? group : group.substring(0, pos).trim();
}
/**
* Can be used to programmatically set the username reported by {@link #getCurrentUser()}
* @param username The username to set - if {@code null} then {@link #CURRENT_USER_OVERRIDE_PROP}
* will be consulted
*/
public static void setCurrentUser(String username) {
synchronized (CURRENT_USER_HOLDER) {
CURRENT_USER_HOLDER.set(username);
}
}
/**
* Resolves the reported Java version by consulting {@link #JAVA_VERSION_OVERRIDE_PROP}.
* If not set, then "java.version" property is used
* @return The resolved {@link VersionInfo} - never {@code null}
* @see #setJavaVersion(VersionInfo)
*/
public static VersionInfo getJavaVersion() {
VersionInfo version;
synchronized (JAVA_VERSION_HOLDER) {
version = JAVA_VERSION_HOLDER.get();
if (version != null) { // first time ?
return version;
}
String value = System.getProperty(JAVA_VERSION_OVERRIDE_PROP, System.getProperty("java.version"));
// e.g.: 1.7.5_30
value = ValidateUtils.checkNotNullAndNotEmpty(value, "No configured Java version value").replace('_', '.');
// clean up any non-digits - in case something like 1.6.8_25-b323
for (int index = 0; index < value.length(); index++) {
char ch = value.charAt(index);
if ((ch == '.') || ((ch >= '0') && (ch <= '9'))) {
continue;
}
value = value.substring(0, index);
break;
}
version = ValidateUtils.checkNotNull(VersionInfo.parse(value), "No version parsed for %s", value);
JAVA_VERSION_HOLDER.set(version);
}
return version;
}
/**
* Set programmatically the reported Java version
* @param version The version - if {@code null} then it will be automatically resolved
*/
public static void setJavaVersion(VersionInfo version) {
synchronized (JAVA_VERSION_HOLDER) {
JAVA_VERSION_HOLDER.set(version);
}
}
/**
* @param path The original path
* @return A path that can be compared with another one where case
* sensitivity of the underlying O/S has been taken into account -
* never {@code null}
*/
public static String getComparablePath(String path) {
String p = (path == null) ? "" : path;
return isWin32() ? p.toLowerCase() : p;
}
}