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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