jcommons/org.eclipse.statet.jcommons.util/src/org/eclipse/statet/jcommons/runtime/ProcessUtils.java

/*=============================================================================#
 # Copyright (c) 2020 Stephan Wahlbrink and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.jcommons.runtime;

import java.util.List;
import java.util.regex.Pattern;

import org.eclipse.statet.jcommons.lang.NonNullByDefault;


@NonNullByDefault
public class ProcessUtils {
	
	
	private static final Pattern DOUBLE_QUOTE_PATTERN= Pattern.compile("\"", Pattern.LITERAL);  //$NON-NLS-1$
	private static final String DOUBLE_QUOTE_REPLACEMENT= "\\\\\"";  //$NON-NLS-1$
	
	
	/**
	 * Creates an UI presentation (compatible with most shells) of the specified command.
	 * 
	 * @param command the program and arguments (e.g. from {@link ProcessBuilder#command()})
	 * 
	 * @return the command line string
	 */
	public static String generateCommandLine(final List<String> command) {
		if (command.isEmpty()) {
			return ""; //$NON-NLS-1$
		}
		final StringBuilder sb= new StringBuilder();
		for (final String arg : command) {
			final String escaped= DOUBLE_QUOTE_PATTERN
					.matcher(arg)
					.replaceAll(DOUBLE_QUOTE_REPLACEMENT);
			if (escaped.indexOf(' ') >= 0) {
				sb.append('\"');
				sb.append(escaped);
				sb.append('\"');
			}
			else {
				sb.append(escaped);
			}
			sb.append(' ');
		}
		return sb.substring(0, sb.length() - 1);
	}
	
	
	private ProcessUtils() {
	}
	
}