xapian-core/common/append_filename_arg.h

   1 /** @file append_filename_arg.h
   2  *  @brief Append filename argument to a command string with suitable escaping
   3  */
   4 /* Copyright (C) 2003,2004,2007,2012 Olly Betts
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation; either version 2 of the
   9  * License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  19  */
  20
  21 #ifndef XAPIAN_INCLUDED_APPEND_FILENAME_ARG_H
  22 #define XAPIAN_INCLUDED_APPEND_FILENAME_ARG_H
  23
  24 #include <cstring>
  25 #include <string>
  26
  27 /// Append filename argument arg to command cmd with suitable escaping.
  28 static bool
  29 append_filename_argument(std::string & cmd, const std::string & arg) {
  30 #ifdef __WIN32__
  31     cmd.reserve(cmd.size() + arg.size() + 5);
  32     // Prevent a leading "-" on the filename being interpreted as a command
  33     // line option.
  34     if (arg[0] == '-')
  35         cmd += " \".\\";
  36     else
  37         cmd += " \"";
  38
  39     for (std::string::const_iterator i = arg.begin(); i != arg.end(); ++i) {
  40         if (*i == '/') {
  41             // Convert Unix path separators to backslashes.  C library
  42             // functions understand "/" in paths, but we are going to
  43             // call commands like "xcopy" or "rd" which don't.
  44             cmd += '\\';
  45         } else if (*i < 32 || std::strchr("<>\"|*?", *i)) {
  46             // Check for illegal characters in filename.
  47             return false;
  48         } else {
  49             cmd += *i;
  50         }
  51     }
  52     cmd += '"';
  53 #else
  54     // Allow for the typical case of a filename without single quote characters
  55     // in - this reserving is just an optimisation, and the string will grow
  56     // larger if necessary.
  57     cmd.reserve(cmd.size() + arg.size() + 5);
  58
  59     // Prevent a leading "-" on the filename being interpreted as a command
  60     // line option.
  61     if (arg[0] == '-')
  62         cmd += " './";
  63     else
  64         cmd += " '";
  65
  66     for (std::string::const_iterator i = arg.begin(); i != arg.end(); ++i) {
  67         if (*i == '\'') {
  68             // Wrapping the whole argument in single quotes works for
  69             // everything except a single quote - for that we drop out of
  70             // single quotes, then use a backslash-escaped single quote, then
  71             // re-enter single quotes.
  72             cmd += "'\\''";
  73             continue;
  74         }
  75         cmd += *i;
  76     }
  77     cmd += '\'';
  78 #endif
  79     return true;
  80 }
  81
  82 #endif // XAPIAN_INCLUDED_APPEND_FILENAME_ARG_H