gpr-tools/source/app/common/argument_parser/program_options_lite.cpp

/* The copyright in this software is being made available under the BSD
 * License, included below. This software may be subject to other third party
 * and contributor rights, including patent rights, and no such rights are
 * granted under this license.
 *
 * Copyright (c) 2010-2015, ITU/ISO/IEC
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *  * Neither the name of the ITU/ISO/IEC nor the names of its contributors may
 *    be used to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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#include <stdlib.h>
#include <iostream>
#include <fstream>
#include <sstream>
#include <string>
#include <list>
#include <map>
#include <algorithm>
#include "program_options_lite.h"

using namespace std;

namespace program_options_lite
{
    
    Options::~Options()
    {
        for(Options::NamesPtrList::iterator it = opt_list.begin(); it != opt_list.end(); it++)
        {
            delete *it;
        }
    }
    
    void Options::addOption(OptionBase *opt)
    {
        Names* names = new Names();
        names->opt = opt;
        string& opt_string = opt->opt_string;
        
        size_t opt_start = 0;
        for (size_t opt_end = 0; opt_end != string::npos;)
        {
            opt_end = opt_string.find_first_of(',', opt_start);
            bool force_short = 0;
            if (opt_string[opt_start] == '-')
            {
                opt_start++;
                force_short = 1;
            }
            string opt_name = opt_string.substr(opt_start, opt_end - opt_start);
            if (force_short || opt_name.size() == 1)
            {
                names->opt_short.push_back(opt_name);
                opt_short_map[opt_name].push_back(names);
            }
            else
            {
                names->opt_long.push_back(opt_name);
                opt_long_map[opt_name].push_back(names);
            }
            opt_start += opt_end + 1;
        }
        opt_list.push_back(names);
    }
    
    /* Helper method to initiate adding options to Options */
    OptionSpecific Options::addOptions()
    {
        return OptionSpecific(*this);
    }
    
    static void setOptions(Options::NamesPtrList& opt_list, const string& value)
    {
        /* multiple options may be registered for the same name:
         *   allow each to parse value */
        for (Options::NamesPtrList::iterator it = opt_list.begin(); it != opt_list.end(); ++it)
        {
            (*it)->opt->parse(value);
        }
    }
    
    static const char spaces[41] = "                                        ";
    
    /* format help text for a single option:
     * using the formatting: "-x, --long",
     * if a short/long option isn't specified, it is not printed
     */
    static void doHelpOpt(ostream& out, const Options::Names& entry, unsigned pad_short = 0)
    {
        pad_short = min(pad_short, 8u);
        
        if (!entry.opt_short.empty())
        {
            unsigned pad = max((int)pad_short - (int)entry.opt_short.front().size(), 0);
            out << "-" << entry.opt_short.front();
            if (!entry.opt_long.empty())
            {
                out << ", ";
            }
            out << &(spaces[40 - pad]);
        }
        else
        {
            out << "   ";
            out << &(spaces[40 - pad_short]);
        }
        
        if (!entry.opt_long.empty())
        {
            out << "--" << entry.opt_long.front();
        }
    }
    
    /* format the help text */
    void doHelp(ostream& out, Options& opts, unsigned columns)
    {
        const unsigned pad_short = 3;
        /* first pass: work out the longest option name */
        unsigned max_width = 0;
        for(Options::NamesPtrList::iterator it = opts.opt_list.begin(); it != opts.opt_list.end(); it++)
        {
            ostringstream line(ios_base::out);
            doHelpOpt(line, **it, pad_short);
            max_width = max(max_width, (unsigned) line.tellp());
        }
        
        unsigned opt_width = min(max_width+2, 28u + pad_short) + 2;
        unsigned desc_width = columns - opt_width;
        
        /* second pass: write out formatted option and help text.
         *  - align start of help text to start at opt_width
         *  - if the option text is longer than opt_width, place the help
         *    text at opt_width on the next line.
         */
        for(Options::NamesPtrList::iterator it = opts.opt_list.begin(); it != opts.opt_list.end(); it++)
        {
            ostringstream line(ios_base::out);
            line << "  ";
            doHelpOpt(line, **it, pad_short);
            
            const string& opt_desc = (*it)->opt->opt_desc;
            if (opt_desc.empty())
            {
                /* no help text: output option, skip further processing */
                cout << line.str() << endl;
                continue;
            }
            size_t currlength = size_t(line.tellp());
            if (currlength > opt_width)
            {
                /* if option text is too long (and would collide with the
                 * help text, split onto next line */
                line << endl;
                currlength = 0;
            }
            /* split up the help text, taking into account new lines,
             *   (add opt_width of padding to each new line) */
            for (size_t newline_pos = 0, cur_pos = 0; cur_pos != string::npos; currlength = 0)
            {
                /* print any required padding space for vertical alignment */
                line << &(spaces[40 - opt_width + currlength]);
                newline_pos = opt_desc.find_first_of('\n', newline_pos);
                if (newline_pos != string::npos)
                {
                    /* newline found, print substring (newline needn't be stripped) */
                    newline_pos++;
                    line << opt_desc.substr(cur_pos, newline_pos - cur_pos);
                    cur_pos = newline_pos;
                    continue;
                }
                if (cur_pos + desc_width > opt_desc.size())
                {
                    /* no need to wrap text, remainder is less than avaliable width */
                    line << opt_desc.substr(cur_pos);
                    break;
                }
                /* find a suitable point to split text (avoid spliting in middle of word) */
                size_t split_pos = opt_desc.find_last_of(' ', cur_pos + desc_width);
                if (split_pos != string::npos)
                {
                    /* eat up multiple space characters */
                    split_pos = opt_desc.find_last_not_of(' ', split_pos) + 1;
                }
                
                /* bad split if no suitable space to split at.  fall back to width */
                bool bad_split = split_pos == string::npos || split_pos <= cur_pos;
                if (bad_split)
                {
                    split_pos = cur_pos + desc_width;
                }
                line << opt_desc.substr(cur_pos, split_pos - cur_pos);
                
                /* eat up any space for the start of the next line */
                if (!bad_split)
                {
                    split_pos = opt_desc.find_first_not_of(' ', split_pos);
                }
                cur_pos = newline_pos = split_pos;
                
                if (cur_pos >= opt_desc.size())
                {
                    break;
                }
                line << endl;
            }
            
            cout << line.str() << endl;
        }
    }
    
    bool storePair(Options& opts, bool allow_long, bool allow_short, const string& name, const string& value)
    {
        bool found = false;
        Options::NamesMap::iterator opt_it;
        if (allow_long)
        {
            opt_it = opts.opt_long_map.find(name);
            if (opt_it != opts.opt_long_map.end())
            {
                found = true;
            }
        }
        
        /* check for the short list */
        if (allow_short && !(found && allow_long))
        {
            opt_it = opts.opt_short_map.find(name);
            if (opt_it != opts.opt_short_map.end())
            {
                found = true;
            }
        }
        
        if (!found)
        {
            /* not found */
            cerr << "Unknown option: `" << name << "' (value:`" << value << "')" << endl;
            return false;
        }
        
        setOptions((*opt_it).second, value);
        return true;
    }
    
    bool storePair(Options& opts, const string& name, const string& value)
    {
        return storePair(opts, true, true, name, value);
    }
    
    /**
     * returns number of extra arguments consumed
     */
    unsigned parseGNU(Options& opts, unsigned argc, const char* argv[])
    {
        /* gnu style long options can take the forms:
         *  --option=arg
         *  --option arg
         */
        string arg(argv[0]);
        size_t arg_opt_start = arg.find_first_not_of('-');
        size_t arg_opt_sep = arg.find_first_of('=');
        string option = arg.substr(arg_opt_start, arg_opt_sep - arg_opt_start);
        
        unsigned extra_argc_consumed = 0;
        if (arg_opt_sep == string::npos)
        {
            /* no argument found => argument in argv[1] (maybe) */
            /* xxx, need to handle case where option isn't required */
#if 0
            /* commented out, to return to true GNU style processing
             * where longopts have to include an =, otherwise they are
             * booleans */
            if (argc == 1)
            {
                return 0; /* run out of argv for argument */
            }
            extra_argc_consumed = 1;
#endif
            if(!storePair(opts, true, false, option, "1"))
            {
                return 0;
            }
        }
        else
        {
            /* argument occurs after option_sep */
            string val = arg.substr(arg_opt_sep + 1);
            storePair(opts, true, false, option, val);
        }
        
        return extra_argc_consumed;
    }
    
    unsigned parseSHORT(Options& opts, unsigned argc, const char* argv[])
    {
        /* short options can take the forms:
         *  --option arg
         *  -option arg
         */
        string arg(argv[0]);
        size_t arg_opt_start = arg.find_first_not_of('-');
        string option = arg.substr(arg_opt_start);
        /* lookup option */
        
        /* argument in argv[1] */
        /* xxx, need to handle case where option isn't required */
        if (argc == 1)
        {
            cerr << "Not processing option without argument `" << option << "'" << endl;
            return 0; /* run out of argv for argument */
        }
        storePair(opts, false, true, option, string(argv[1]));
        
        return 1;
    }
    
    list<const char*>
    scanArgv(Options& opts, unsigned argc, const char* argv[])
    {
        /* a list for anything that didn't get handled as an option */
        list<const char*> non_option_arguments;
        
        for(unsigned i = 1; i < argc; i++)
        {
            if (argv[i][0] != '-')
            {
                non_option_arguments.push_back(argv[i]);
                continue;
            }
            
            if (argv[i][1] == 0)
            {
                /* a lone single dash is an argument (usually signifying stdin) */
                non_option_arguments.push_back(argv[i]);
                continue;
            }
            
            if (argv[i][1] != '-')
            {
                /* handle short (single dash) options */
#if 0
                i += parsePOSIX(opts, argc - i, &argv[i]);
#else
                i += parseSHORT(opts, argc - i, &argv[i]);
#endif
                continue;
            }
            
            if (argv[i][2] == 0)
            {
                /* a lone double dash ends option processing */
                while (++i < argc)
                {
                    non_option_arguments.push_back(argv[i]);
                }
                break;
            }
            
            /* handle long (double dash) options */
            i += parseGNU(opts, argc - i, &argv[i]);
        }
        
        return non_option_arguments;
    }
    
    void scanLine(Options& opts, string& line)
    {
        /* strip any leading whitespace */
        size_t start = line.find_first_not_of(" \t\n\r");
        if (start == string::npos)
        {
            /* blank line */
            return;
        }
        if (line[start] == '#')
        {
            /* comment line */
            return;
        }
        /* look for first whitespace or ':' after the option end */
        size_t option_end = line.find_first_of(": \t\n\r",start);
        string option = line.substr(start, option_end - start);
        
        /* look for ':', eat up any whitespace first */
        start = line.find_first_not_of(" \t\n\r", option_end);
        if (start == string::npos)
        {
            /* error: badly formatted line */
            return;
        }
        if (line[start] != ':')
        {
            /* error: badly formatted line */
            return;
        }
        
        /* look for start of value string -- eat up any leading whitespace */
        start = line.find_first_not_of(" \t\n\r", ++start);
        if (start == string::npos)
        {
            /* error: badly formatted line */
            return;
        }
        
        /* extract the value part, which may contain embedded spaces
         * by searching for a word at a time, until we hit a comment or end of line */
        size_t value_end = start;
        do
        {
            if (line[value_end] == '#')
            {
                /* rest of line is a comment */
                value_end--;
                break;
            }
            value_end = line.find_first_of(" \t\n\r", value_end);
            /* consume any white space, incase there is another word.
             * any trailing whitespace will be removed shortly */
            value_end = line.find_first_not_of(" \t\n\r", value_end);
        } while (value_end != string::npos);
        /* strip any trailing space from value*/
        value_end = line.find_last_not_of(" \t\n\r", value_end);
        
        string value;
        if (value_end >= start)
        {
            value = line.substr(start, value_end +1 - start);
        }
        else
        {
            /* error: no value */
            return;
        }
        
        /* store the value in option */
        storePair(opts, true, false, option, value);
    }
    
    void scanFile(Options& opts, istream& in)
    {
        do
        {
            string line;
            getline(in, line);
            scanLine(opts, line);
        } while(!!in);
    }
    
    /* for all options in opts, set their storage to their specified
     * default value */
    void setDefaults(Options& opts)
    {
        for(Options::NamesPtrList::iterator it = opts.opt_list.begin(); it != opts.opt_list.end(); it++)
        {
            (*it)->opt->setDefault();
        }
    }
    
    void parseConfigFile(Options& opts, const string& filename)
    {
        ifstream cfgstream(filename.c_str(), ifstream::in);
        if (!cfgstream)
        {
            cerr << "Failed to open config file: `" << filename << "'" << endl;
            exit(EXIT_FAILURE);
        }
        scanFile(opts, cfgstream);
    }
}