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/*******************************************************************************
* $Revision: 1.2 $
* $Date: 2001/09/11 06:19:36 $
* $Author: vyzo $
*
* Contents: A streambuf which uses the GNU readline library for line I/O
* (c) 2001 by Dimitris Vyzovitis [vyzo@media.mit.edu]
*
* 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., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*
******************************************************************************/
#ifndef _READLINEBUF_H_
#define _READLINEBUF_H_
#include <iostream>
#include <cstring>
#include <cassert>
#include <cstdlib>
#include <cstdio>
#include <readline/readline.h>
#include <readline/history.h>
#if (defined __GNUC__) && (__GNUC__ < 3)
#include <streambuf.h>
#else
#include <streambuf>
using std::streamsize;
using std::streambuf;
#endif
class readlinebuf : public streambuf {
public:
#if (defined __GNUC__) && (__GNUC__ < 3)
typedef char char_type;
typedef int int_type;
typedef streampos pos_type;
typedef streamoff off_type;
#endif
static const int_type eof = EOF; // this is -1
static const int_type not_eof = 0;
private:
const char* prompt_;
bool history_;
char* line_;
int low_;
int high_;
protected:
virtual int_type showmanyc() const { return high_ - low_; }
virtual streamsize xsgetn( char_type* buf, streamsize n ) {
int rd = n > (high_ - low_)? (high_ - low_) : n;
memcpy( buf, line_, rd );
low_ += rd;
if ( rd < n ) {
low_ = high_ = 0;
free( line_ ); // free( NULL ) is a noop
line_ = readline( prompt_ );
if ( line_ ) {
high_ = strlen( line_ );
if ( history_ && high_ ) add_history( line_ );
rd += xsgetn( buf + rd, n - rd );
}
}
return rd;
}
virtual int_type underflow() {
if ( high_ == low_ ) {
low_ = high_ = 0;
free( line_ ); // free( NULL ) is a noop
line_ = readline( prompt_ );
if ( line_ ) {
high_ = strlen( line_ );
if ( history_ && high_ ) add_history( line_ );
}
}
if ( low_ < high_ ) return line_[low_];
else return eof;
}
virtual int_type uflow() {
int_type c = underflow();
if ( c != eof ) ++low_;
return c;
}
virtual int_type pbackfail( int_type c = eof ) {
if ( low_ > 0 ) --low_;
else if ( c != eof ) {
if ( high_ > 0 ) {
char* nl = (char*)realloc( line_, high_ + 1 );
if ( nl ) {
line_ = (char*)memcpy( nl + 1, line_, high_ );
high_ += 1;
line_[0] = char( c );
} else return eof;
} else {
assert( !line_ );
line_ = (char*)malloc( sizeof( char ) );
*line_ = char( c );
high_ = 1;
}
} else return eof;
return not_eof;
}
public:
readlinebuf( const char* prompt = NULL, bool history = true )
: prompt_( prompt ), history_( history ),
line_( NULL ), low_( 0 ), high_( 0 ) {
setbuf( 0, 0 );
}
};
#endif
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