io.quarkiverse.githubapp.command.airline.runtime.util.Commandline Maven / Gradle / Ivy

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/*
 *  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
 *
 *      https://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 io.quarkiverse.githubapp.command.airline.runtime.util;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.StringTokenizer;

/**
 * Extracted from Ant - https://github.com/apache/ant with a few adjustments.
 * Will require some improvements regarding escaping.
 */
public final class Commandline {

    private Commandline() {
    }

    /**
     * Crack a command line.
     * 
     * @param toProcess the command line to process.
     * @return the command line broken into strings.
     *         An empty or null toProcess parameter results in a zero sized array.
     */
    public static List translateCommandline(String toProcess) {
        if (toProcess == null || toProcess.isEmpty()) {
            //no command? no string
            return Collections.emptyList();
        }
        // parse with a simple finite state machine

        final int normal = 0;
        final int inQuote = 1;
        final int inDoubleQuote = 2;
        int state = normal;
        final StringTokenizer tok = new StringTokenizer(toProcess, "\"' ", true);
        final ArrayList result = new ArrayList<>();
        final StringBuilder current = new StringBuilder();
        boolean lastTokenHasBeenQuoted = false;

        while (tok.hasMoreTokens()) {
            String nextTok = tok.nextToken();
            switch (state) {
                case inQuote:
                    if ("'".equals(nextTok)) {
                        lastTokenHasBeenQuoted = true;
                        state = normal;
                    } else {
                        current.append(nextTok);
                    }
                    break;
                case inDoubleQuote:
                    if ("\"".equals(nextTok)) {
                        lastTokenHasBeenQuoted = true;
                        state = normal;
                    } else {
                        current.append(nextTok);
                    }
                    break;
                default:
                    if ("'".equals(nextTok)) {
                        state = inQuote;
                    } else if ("\"".equals(nextTok)) {
                        state = inDoubleQuote;
                    } else if (" ".equals(nextTok)) {
                        if (lastTokenHasBeenQuoted || current.length() > 0) {
                            result.add(current.toString());
                            current.setLength(0);
                        }
                    } else {
                        current.append(nextTok);
                    }
                    lastTokenHasBeenQuoted = false;
                    break;
            }
        }
        if (lastTokenHasBeenQuoted || current.length() > 0) {
            result.add(current.toString());
        }
        if (state == inQuote || state == inDoubleQuote) {
            throw new IllegalArgumentException("unbalanced quotes in " + toProcess);
        }
        return result;
    }
}