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 
00212 string
00213 www2id(const string &in, const string &escape, const string &except)
00214 {
00215     string::size_type i = 0;
00216     string res = in;
00217     while ((i = res.find_first_of(escape, i)) != string::npos) {
00218         if (except.find(res.substr(i, 3)) != string::npos) {
00219             i += 3;
00220             continue;
00221         }
00222         res.replace(i, 3, unhexstring(res.substr(i + 1, 2)));
00223     }
00224 
00225     return res;
00226 }
00227 
00228 static string
00229 entity(char c)
00230 {
00231     switch (c) {
00232     case '>': return "&gt;";
00233     case '<': return "&lt;";
00234     case '&': return "&amp;";
00235     case '\'': return "&apos;";
00236     case '\"': return "&quot;";
00237     default:
00238         throw InternalErr(__FILE__, __LINE__, "Unrecognized character.");
00239     }
00240 }
00241 
00248 string
00249 id2xml(string in, const string &not_allowed)
00250 {
00251     string::size_type i = 0;
00252 
00253     while ((i = in.find_first_of(not_allowed, i)) != string::npos) {
00254         in.replace(i, 1, entity(in[i]));
00255         i++;
00256     }
00257 
00258     return in;
00259 }
00260 
00266 string
00267 xml2id(string in)
00268 {
00269     string::size_type i = 0;
00270 
00271     while ((i = in.find("&gt;", i)) != string::npos)
00272         in.replace(i, 4, ">");
00273 
00274     i = 0;
00275     while ((i = in.find("&lt;", i)) != string::npos)
00276         in.replace(i, 4, "<");
00277 
00278     i = 0;
00279     while ((i = in.find("&amp;", i)) != string::npos)
00280         in.replace(i, 5, "&");
00281 
00282     i = 0;
00283     while ((i = in.find("&apos;", i)) != string::npos)
00284         in.replace(i, 6, "'");
00285 
00286     i = 0;
00287     while ((i = in.find("&quot;", i)) != string::npos)
00288         in.replace(i, 6, "\"");
00289 
00290     return in;
00291 }
00292 
00298 string
00299 esc2underscore(string s)
00300 {
00301     string::size_type pos;
00302     while ((pos = s.find('%')) != string::npos)
00303         s.replace(pos, 3, "_");
00304 
00305     return s;
00306 }
00307 
00308 
00312 string
00313 escattr(string s)
00314 {
00315     const string printable = " ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789~`!@#$%^&*()_-+={[}]|\\:;<,>.?/'\"";
00316     const string ESC = "\\";
00317     const string DOUBLE_ESC = ESC + ESC;
00318     const string QUOTE = "\"";
00319     const string ESCQUOTE = ESC + QUOTE;
00320 
00321     // escape non-printing characters with octal escape
00322     string::size_type ind = 0;
00323     while ((ind = s.find_first_not_of(printable, ind)) != s.npos)
00324         s.replace(ind, 1, ESC + octstring(s[ind]));
00325 
00326     // escape \ with a second backslash
00327     ind = 0;
00328     while ((ind = s.find(ESC, ind)) != s.npos) {
00329         s.replace(ind, 1, DOUBLE_ESC);
00330         ind += DOUBLE_ESC.length();
00331     }
00332 
00333     // escape " with backslash
00334     ind = 0;
00335     while ((ind = s.find(QUOTE, ind)) != s.npos) {
00336         s.replace(ind, 1, ESCQUOTE);
00337         ind += ESCQUOTE.length();
00338     }
00339 
00340     return s;
00341 }
00342 
00351 string
00352 unescattr(string s)
00353 {
00354     Regex octal("\\\\[0-3][0-7][0-7]");  // matches 4 characters
00355     Regex esc_quote("\\\\\"");  // matches 3 characters
00356     Regex esc_esc("\\\\\\\\");      // matches 2 characters
00357     const string ESC = "\\";
00358     const string QUOTE = "\"";
00359     int matchlen;
00360     unsigned int index;
00361 
00362     DBG(cerr << "0XX" << s << "XXX" << endl);
00363     // unescape any escaped backslashes
00364     index = esc_esc.search(s.c_str(), s.length(), matchlen, 0);
00365     while (index < s.length()) {
00366         DBG(cerr << "1aXX" << s << "XXX index: " << index << endl);
00367         s.replace(index, 2, ESC);
00368         DBG(cerr << "1bXX" << s << "XXX index: " << index << endl);
00369         index = esc_esc.search(s.c_str(), s.length(), matchlen, 0);
00370     }
00371 
00372     // unescape any escaped double quote characters
00373     index = esc_quote.search(s.c_str(), s.length(), matchlen, 0);
00374     while (index < s.length()) {
00375         s.replace(index, 2, QUOTE);
00376         DBG(cerr << "2XX" << s << "XXX index: " << index << endl);
00377         index = esc_quote.search(s.c_str(), s.length(), matchlen, 0);
00378     }
00379 
00380     // unescape octal characters
00381     index = octal.search(s.c_str(), s.length(), matchlen, 0);
00382     while (index < s.length()) {
00383         s.replace(index, 4, unoctstring(s.substr(index + 1, 3)));
00384         DBG(cerr << "3XX" << s << "XXX index: " << index << endl);
00385         index = octal.search(s.c_str(), s.length(), matchlen, 0);
00386     }
00387 
00388     DBG(cerr << "4XX" << s << "XXX" << endl);
00389     return s;
00390 }
00391 
00392 string
00393 munge_error_message(string msg)
00394 {
00395     // First, add enclosing quotes if needed.
00396     if (*msg.begin() != '"')
00397         msg.insert(msg.begin(), '"');
00398     if (*(msg.end() - 1) != '"')
00399         msg += "\"";
00400 
00401     // Now escape any internal double quotes that aren't escaped.
00402     string::iterator miter;
00403     for (miter = msg.begin() + 1; miter != msg.end() - 1; miter++)
00404         if (*miter == '"' && *(miter - 1) != '\\')
00405             miter = msg.insert(miter, '\\');
00406 
00407     return msg;
00408 }
00409 
00410 } // namespace libdap
00411 

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