simgear/Misc/fgstream.cxx
1998-09-24 15:22:17 +00:00

184 lines
3.7 KiB
C++

// zlib input file stream wrapper.
//
// Written by Bernie Bright, 1998
//
// Copyright (C) 1998 Bernie Bright - bbright@c031.aone.net.au
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
//
// $Id$
// (Log is kept at end of this file)
#include <ctype.h> // isspace()
#include "fgstream.hxx"
//-----------------------------------------------------------------------------
//
// Open a possibly gzipped file for reading.
//
fg_gzifstream::fg_gzifstream( const string& name, int io_mode )
{
open( name, io_mode );
}
//-----------------------------------------------------------------------------
//
// Attach a stream to an already opened file descriptor.
//
fg_gzifstream::fg_gzifstream( int fd, int io_mode )
: gzstream( fd, io_mode )
{
}
//-----------------------------------------------------------------------------
//
// Open a possibly gzipped file for reading.
// If the initial open fails and the filename has a ".gz" extension then
// remove the extension and try again.
// If the initial open fails and the filename doesn't have a ".gz" extension
// then append ".gz" and try again.
//
void
fg_gzifstream::open( const string& name, int io_mode )
{
gzstream.open( name.c_str(), io_mode );
if ( gzstream.fail() )
{
string s = name;
if ( s.substr( s.length() - 3, 3 ) == ".gz" )
{
// remove ".gz" suffix
s.replace( s.length() - 3, 3, "" );
// s.erase( s.length() - 3, 3 );
}
else
{
// Append ".gz" suffix
s += ".gz";
}
// Try again.
gzstream.open( s.c_str(), io_mode );
}
}
//-----------------------------------------------------------------------------
//
// Remove whitespace characters from the stream.
//
istream&
fg_gzifstream::eat_whitespace()
{
char c;
while ( gzstream.get(c) )
{
if ( ! isspace( c ) )
{
// put pack the non-space character
gzstream.putback(c);
break;
}
}
return gzstream;
}
//-----------------------------------------------------------------------------
//
// Remove whitspace chatacters and comment lines from a stream.
//
istream&
fg_gzifstream::eat_comments()
{
for (;;)
{
// skip whitespace
eat_whitespace();
char c;
gzstream.get( c );
if ( c != '#' )
{
// not a comment
gzstream.putback(c);
break;
}
// skip to end of line.
while ( gzstream.get(c) && (c != '\n' && c != '\r') )
;
}
return gzstream;
}
//
// Manipulators
//
istream&
skipeol( istream& in )
{
char c = 0;
// skip to end of line.
while ( in.get(c) && (c != '\n' && c != '\r') )
;
// \r\n ?
return in;
}
istream&
skipws( istream& in )
{
char c;
while ( in.get(c) )
{
if ( ! isspace( c ) )
{
// put pack the non-space character
in.putback(c);
break;
}
}
return in;
}
istream&
skipcomment( istream& in )
{
while ( in )
{
// skip whitespace
in >> skipws;
char c;
if ( in.get( c ) && c != '#' )
{
// not a comment
in.putback(c);
break;
}
in >> skipeol;
}
return in;
}
// $Log$
// Revision 1.2 1998/09/24 15:22:17 curt
// Additional enhancements.
//
// Revision 1.1 1998/09/01 19:06:29 curt
// Initial revision.
//