escaping.cc

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00001 
00002 // -*- mode: c++; c-basic-offset:4 -*-
00003 
00004 // This file is part of libdap, A C++ implementation of the OPeNDAP Data
00005 // Access Protocol.
00006 
00007 // Copyright (c) 2002,2003 OPeNDAP, Inc.
00008 // Author: James Gallagher <jgallagher@opendap.org>
00009 //
00010 // This library is free software; you can redistribute it and/or
00011 // modify it under the terms of the GNU Lesser General Public
00012 // License as published by the Free Software Foundation; either
00013 // version 2.1 of the License, or (at your option) any later version.
00014 //
00015 // This library is distributed in the hope that it will be useful,
00016 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00017 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00018 // Lesser General Public License for more details.
00019 //
00020 // You should have received a copy of the GNU Lesser General Public
00021 // License along with this library; if not, write to the Free Software
00022 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
00023 //
00024 // You can contact OPeNDAP, Inc. at PO Box 112, Saunderstown, RI. 02874-0112.
00025 
00026 // Copyright (c) 1996, California Institute of Technology.
00027 // ALL RIGHTS RESERVED.   U.S. Government Sponsorship acknowledged.
00028 //
00029 // Please read the full copyright notice in the file COPYRIGHT_URI
00030 // in this directory.
00031 //
00032 // Author: Todd Karakashian, NASA/Jet Propulsion Laboratory
00033 //         Todd.K.Karakashian@jpl.nasa.gov
00034 //
00035 // $RCSfile: escaping.cc,v $ - Miscellaneous routines for OPeNDAP HDF server
00036 //
00037 // These two routines are for escaping/unescaping strings that are identifiers
00038 // in DAP2
00039 // id2www() -- escape (using WWW hex codes) non-allowable characters in a
00040 // DAP2 identifier
00041 // www2id() -- given an WWW hexcode escaped identifier, restore it
00042 //
00043 // These two routines are for escaping/unescaping strings storing attribute
00044 // values.  They use traditional octal escapes (\nnn) because they are
00045 // intended to be viewed by a user
00046 // escattr() -- escape (using traditional octal backslash) non-allowable
00047 // characters in the value of a DAP2 attribute
00048 // unescattr() -- given an octally escaped string, restore it
00049 //
00050 // These are routines used by the above, not intended to be called directly:
00051 //
00052 // hexstring()
00053 // unhexstring()
00054 // octstring()
00055 // unoctstring()
00056 //
00057 // -Todd
00058 
00059 #include <ctype.h>
00060 
00061 #include <iomanip>
00062 #include <string>
00063 #include <sstream>
00064 
00065 #include "GNURegex.h"
00066 #include "Error.h"
00067 #include "InternalErr.h"
00068 // #define DODS_DEBUG
00069 #include "debug.h"
00070 
00071 using namespace std;
00072 
00073 namespace libdap {
00074 
00075 // The next four functions were originally defined static, but I removed that
00076 // to make testing them (see generalUtilTest.cc) easier to write. 5/7/2001
00077 // jhrg
00078 
00079 string
00080 hexstring(unsigned char val)
00081 {
00082     ostringstream buf;
00083     buf << hex << setw(2) << setfill('0')
00084     << static_cast<unsigned int>(val);
00085 
00086     return buf.str();
00087 }
00088 
00089 string
00090 unhexstring(string s)
00091 {
00092     int val;
00093     istringstream ss(s);
00094     ss >> hex >> val;
00095     char tmp_str[2];
00096     tmp_str[0] = static_cast<char>(val);
00097     tmp_str[1] = '\0';
00098     return string(tmp_str);
00099 }
00100 
00101 string
00102 octstring(unsigned char val)
00103 {
00104     ostringstream buf;
00105     buf << oct << setw(3) << setfill('0')
00106     << static_cast<unsigned int>(val);
00107 
00108     return buf.str();
00109 }
00110 
00111 string
00112 unoctstring(string s)
00113 {
00114     int val;
00115 
00116     istringstream ss(s);
00117     ss >> oct >> val;
00118 
00119     DBG(cerr << "unoctstring: " << val << endl);
00120 
00121     char tmp_str[2];
00122     tmp_str[0] = static_cast<char>(val);
00123     tmp_str[1] = '\0';
00124     return string(tmp_str);
00125 }
00126 
00151 string
00152 id2www(string in, const string &allowable)
00153 {
00154     string::size_type i = 0;
00155 
00156     while ((i = in.find_first_not_of(allowable, i)) != string::npos) {
00157         in.replace(i, 1, "%" + hexstring(in[i]));
00158         i++;
00159     }
00160 
00161     return in;
00162 }
00163 
00174 string
00175 id2www_ce(string in, const string &allowable)
00176 {
00177     return id2www(in, allowable);
00178 }
00179 
00208 string
00209 www2id(const string &in, const string &escape, const string &except)
00210 {
00211     string::size_type i = 0;
00212     string res = in;
00213     while ((i = res.find_first_of(escape, i)) != string::npos) {
00214         if (res.substr(i, 3) == except) {
00215             i += 3;
00216             continue;
00217         }
00218         res.replace(i, 3, unhexstring(res.substr(i + 1, 2)));
00219     }
00220 
00221     return res;
00222 }
00223 
00224 static string
00225 entity(char c)
00226 {
00227     switch (c) {
00228     case '>': return "&gt;";
00229     case '<': return "&lt;";
00230     case '&': return "&amp;";
00231     case '\'': return "&apos;";
00232     case '\"': return "&quot;";
00233     default:
00234         throw InternalErr(__FILE__, __LINE__, "Unrecognized character.");
00235     }
00236 }
00237 
00244 string
00245 id2xml(string in, const string &not_allowed)
00246 {
00247     string::size_type i = 0;
00248 
00249     while ((i = in.find_first_of(not_allowed, i)) != string::npos) {
00250         in.replace(i, 1, entity(in[i]));
00251         i++;
00252     }
00253 
00254     return in;
00255 }
00256 
00262 string
00263 xml2id(string in)
00264 {
00265     string::size_type i = 0;
00266 
00267     while ((i = in.find("&gt;", i)) != string::npos)
00268         in.replace(i, 4, ">");
00269 
00270     i = 0;
00271     while ((i = in.find("&lt;", i)) != string::npos)
00272         in.replace(i, 4, "<");
00273 
00274     i = 0;
00275     while ((i = in.find("&amp;", i)) != string::npos)
00276         in.replace(i, 5, "&");
00277 
00278     i = 0;
00279     while ((i = in.find("&apos;", i)) != string::npos)
00280         in.replace(i, 6, "'");
00281 
00282     i = 0;
00283     while ((i = in.find("&quot;", i)) != string::npos)
00284         in.replace(i, 6, "\"");
00285 
00286     return in;
00287 }
00288 
00294 string
00295 esc2underscore(string s)
00296 {
00297     string::size_type pos;
00298     while ((pos = s.find('%')) != string::npos)
00299         s.replace(pos, 3, "_");
00300 
00301     return s;
00302 }
00303 
00304 
00308 string
00309 escattr(string s)
00310 {
00311     const string printable = " ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789~`!@#$%^&*()_-+={[}]|\\:;<,>.?/'\"";
00312     const string ESC = "\\";
00313     const string DOUBLE_ESC = ESC + ESC;
00314     const string QUOTE = "\"";
00315     const string ESCQUOTE = ESC + QUOTE;
00316 
00317     // escape non-printing characters with octal escape
00318     string::size_type ind = 0;
00319     while ((ind = s.find_first_not_of(printable, ind)) != s.npos)
00320         s.replace(ind, 1, ESC + octstring(s[ind]));
00321 
00322     // escape \ with a second backslash
00323     ind = 0;
00324     while ((ind = s.find(ESC, ind)) != s.npos) {
00325         s.replace(ind, 1, DOUBLE_ESC);
00326         ind += DOUBLE_ESC.length();
00327     }
00328 
00329     // escape " with backslash
00330     ind = 0;
00331     while ((ind = s.find(QUOTE, ind)) != s.npos) {
00332         s.replace(ind, 1, ESCQUOTE);
00333         ind += ESCQUOTE.length();
00334     }
00335 
00336     return s;
00337 }
00338 
00347 string
00348 unescattr(string s)
00349 {
00350     Regex octal("\\\\[0-3][0-7][0-7]");  // matches 4 characters
00351     Regex esc_quote("\\\\\"");  // matches 3 characters
00352     Regex esc_esc("\\\\\\\\");      // matches 2 characters
00353     const string ESC = "\\";
00354     const string QUOTE = "\"";
00355     int matchlen;
00356     unsigned int index;
00357 
00358     DBG(cerr << "0XX" << s << "XXX" << endl);
00359     // unescape any escaped backslashes
00360     index = esc_esc.search(s.c_str(), s.length(), matchlen, 0);
00361     while (index < s.length()) {
00362         DBG(cerr << "1aXX" << s << "XXX index: " << index << endl);
00363         s.replace(index, 2, ESC);
00364         DBG(cerr << "1bXX" << s << "XXX index: " << index << endl);
00365         index = esc_esc.search(s.c_str(), s.length(), matchlen, 0);
00366     }
00367 
00368     // unescape any escaped double quote characters
00369     index = esc_quote.search(s.c_str(), s.length(), matchlen, 0);
00370     while (index < s.length()) {
00371         s.replace(index, 2, QUOTE);
00372         DBG(cerr << "2XX" << s << "XXX index: " << index << endl);
00373         index = esc_quote.search(s.c_str(), s.length(), matchlen, 0);
00374     }
00375 
00376     // unescape octal characters
00377     index = octal.search(s.c_str(), s.length(), matchlen, 0);
00378     while (index < s.length()) {
00379         s.replace(index, 4, unoctstring(s.substr(index + 1, 3)));
00380         DBG(cerr << "3XX" << s << "XXX index: " << index << endl);
00381         index = octal.search(s.c_str(), s.length(), matchlen, 0);
00382     }
00383 
00384     DBG(cerr << "4XX" << s << "XXX" << endl);
00385     return s;
00386 }
00387 
00388 string
00389 munge_error_message(string msg)
00390 {
00391     // First, add enclosing quotes if needed.
00392     if (*msg.begin() != '"')
00393         msg.insert(msg.begin(), '"');
00394     if (*(msg.end() - 1) != '"')
00395         msg += "\"";
00396 
00397     // Now escape any internal double quotes that aren't escaped.
00398     string::iterator miter;
00399     for (miter = msg.begin() + 1; miter != msg.end() - 1; miter++)
00400         if (*miter == '"' && *(miter - 1) != '\\')
00401             miter = msg.insert(miter, '\\');
00402 
00403     return msg;
00404 }
00405 
00406 } // namespace libdap
00407 

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