[deliverable/binutils-gdb.git] / readline / examples / readlinebuf.h

/*******************************************************************************
 * $Revision$
 * $Date$
 * $Author$
 *
 * 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
Commit	Line	Data
9255ee31	1	/*******************************************************************************
5836a818 PP	2	* $Revision$
	3	* $Date$
	4	* $Author$
9255ee31 EZ	5	*
	6	* Contents: A streambuf which uses the GNU readline library for line I/O
	7	* (c) 2001 by Dimitris Vyzovitis [vyzo@media.mit.edu]
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License as published by
cc88a640	11	* the Free Software Foundation; either version 2 of the License, or
9255ee31 EZ	12	* (at your option) any later version.
	13	*
	14	* This program is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	17	* General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU General Public
	20	* License along with this program; if not, write to the Free
	21	* Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	22	* MA 02111-1307 USA
	23	*
	24	******************************************************************************/
	25
	26	#ifndef _READLINEBUF_H_
	27	#define _READLINEBUF_H_
	28
	29	#include <iostream>
	30	#include <cstring>
	31	#include <cassert>
	32	#include <cstdlib>
	33	#include <cstdio>
	34
	35	#include <readline/readline.h>
	36	#include <readline/history.h>
	37
	38	#if (defined __GNUC__) && (__GNUC__ < 3)
	39	#include <streambuf.h>
	40	#else
	41	#include <streambuf>
	42	using std::streamsize;
	43	using std::streambuf;
	44	#endif
	45
	46	class readlinebuf : public streambuf {
	47	public:
	48	#if (defined __GNUC__) && (__GNUC__ < 3)
	49	typedef char char_type;
	50	typedef int int_type;
	51	typedef streampos pos_type;
	52	typedef streamoff off_type;
	53	#endif
	54	static const int_type eof = EOF; // this is -1
	55	static const int_type not_eof = 0;
	56
	57	private:
	58	const char* prompt_;
	59	bool history_;
	60	char* line_;
	61	int low_;
	62	int high_;
	63
	64	protected:
	65
	66	virtual int_type showmanyc() const { return high_ - low_; }
	67
	68	virtual streamsize xsgetn( char_type* buf, streamsize n ) {
	69	int rd = n > (high_ - low_)? (high_ - low_) : n;
	70	memcpy( buf, line_, rd );
	71	low_ += rd;
	72
	73	if ( rd < n ) {
	74	low_ = high_ = 0;
	75	free( line_ ); // free( NULL ) is a noop
76	line_ = readline( prompt_ );
77	if ( line_ ) {
78	high_ = strlen( line_ );
79	if ( history_ && high_ ) add_history( line_ );
80	rd += xsgetn( buf + rd, n - rd );
81	}
82	}
83
84	return rd;
85	}
86
87	virtual int_type underflow() {
88	if ( high_ == low_ ) {
89	low_ = high_ = 0;
90	free( line_ ); // free( NULL ) is a noop
91	line_ = readline( prompt_ );
92	if ( line_ ) {
93	high_ = strlen( line_ );
94	if ( history_ && high_ ) add_history( line_ );
95	}
96	}
97
98	if ( low_ < high_ ) return line_[low_];
99	else return eof;
100	}
101
102	virtual int_type uflow() {
103	int_type c = underflow();
104	if ( c != eof ) ++low_;
105	return c;
106	}
107
108	virtual int_type pbackfail( int_type c = eof ) {
109	if ( low_ > 0 ) --low_;
110	else if ( c != eof ) {
111	if ( high_ > 0 ) {
112	char* nl = (char*)realloc( line_, high_ + 1 );
113	if ( nl ) {
114	line_ = (char*)memcpy( nl + 1, line_, high_ );
115	high_ += 1;
116	line_[0] = char( c );
117	} else return eof;
118	} else {
119	assert( !line_ );
120	line_ = (char*)malloc( sizeof( char ) );
121	*line_ = char( c );
122	high_ = 1;
123	}
124	} else return eof;
125
126	return not_eof;
127	}
128
129	public:
130	readlinebuf( const char* prompt = NULL, bool history = true )
131	: prompt_( prompt ), history_( history ),
132	line_( NULL ), low_( 0 ), high_( 0 ) {
133	setbuf( 0, 0 );
134	}
135
136
137	};
138
139	#endif