Given a string containing a shell command argument, escape the string so that it may be entered on the shell command line. - Java Native OS

Java examples for Native OS:Shell Command

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Description

Given a string containing a shell command argument, escape the string so that it may be entered on the shell command line.

Demo Code

/*******************************************************************************
 * Copyright (c) 2011 Arapiki Solutions Inc.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors://  ww  w.j a  v  a 2s .  c o  m
 *    "Peter Smith <psmith@arapiki.com>" - initial API and 
 *        implementation and/or initial documentation
 *******************************************************************************/
//package com.java2s;

public class Main {
    public static void main(String[] argv) throws Exception {
        String input = "java2s.com";
        System.out.println(shellEscapeString(input));
    }

    /**
     * Given a string containing a shell command argument, escape the string so that it may be
     * entered on the shell command line. For example, an argument that contains spaces must
     * be surrounded by quotation marks. Also, a quotation mark in an argument must be quoted
     * with a backslash (\").
     * 
     * @param input The unescaped shell command arguments.
     * @return The shell-escaped version of the argument.
     */
    public static String shellEscapeString(String input) {

        boolean needsQuoting = false;
        int inputLen = input.length();
        for (int i = 0; i != inputLen; i++) {
            char ch = input.charAt(i);
            if (ch == ' ' || ch == '\r' || ch == '\n' || ch == '\t'
                    || ch == '(' || ch == ')' || ch == '<' || ch == '>'
                    || ch == ';' || ch == '&' || ch == '!' || ch == '$'
                    || ch == '!' || ch == '$' || ch == '\'' || ch == '*'
                    || ch == '?' || ch == '[' || ch == ']' || ch == '{'
                    || ch == '}') {
                needsQuoting = true;
                break;
            }
        }

        /* 
         * If there are no special characters, no quoting is required. Simply
         * return the original string.
         */
        if (!needsQuoting) {
            return input;
        }

        /*
         * Else, create a replacement string, with added '...' and any internal
         * ' characters prefixed by \.
         */
        StringBuffer sb = new StringBuffer(inputLen + 10); /* allow room for quotes */
        sb.append('\'');
        for (int i = 0; i != inputLen; i++) {
            char ch = input.charAt(i);

            /*
             * Single quotes behave oddly. You need to terminate the first quote, then
             * have the \', then restart the quoted string. Therefore, Hello'World
             * must be escaped as 'Hello'\''World'
             */
            if (ch == '\'') {
                sb.append("'\\''");
            } else {
                sb.append(ch);
            }
        }
        sb.append('\'');
        return sb.toString();
    }
}

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