mirror of
https://github.com/genodelabs/genode.git
synced 2024-12-27 17:18:53 +00:00
9ef0f1b6cb
This little library implements rudimentary format-string support. It is useful for porting 3rd-party code that ought not depend on a full libc. Issue #2064
100 lines
2.0 KiB
C++
100 lines
2.0 KiB
C++
/*
|
|
* \brief Facility to write format string into character buffer
|
|
* \author Norman Feske
|
|
* \date 2006-07-17
|
|
*/
|
|
|
|
/*
|
|
* Copyright (C) 2006-2017 Genode Labs GmbH
|
|
*
|
|
* This file is part of the Genode OS framework, which is distributed
|
|
* under the terms of the GNU Affero General Public License version 3.
|
|
*/
|
|
|
|
#ifndef _INCLUDE__FORMAT__SNPRINTF_H_
|
|
#define _INCLUDE__FORMAT__SNPRINTF_H_
|
|
|
|
#include <format/console.h>
|
|
|
|
namespace Format {
|
|
|
|
class String_console;
|
|
|
|
using size_t = __SIZE_TYPE__;
|
|
|
|
/**
|
|
* Print format string into character buffer
|
|
*
|
|
* \param dst destination buffer
|
|
* \param dst_len size of 'dst' in bytes
|
|
* \param format format string followed by the list of arguments
|
|
*
|
|
* \return number of characters written to destination buffer
|
|
*/
|
|
inline size_t snprintf(char *dst, size_t dst_size, const char *format, ...)
|
|
__attribute__((format(printf, 3, 4)));
|
|
}
|
|
|
|
|
|
class Format::String_console : public Console
|
|
{
|
|
private:
|
|
|
|
char *_dst;
|
|
size_t _dst_len;
|
|
size_t _w_offset { 0 };
|
|
|
|
/*
|
|
* Noncopyable
|
|
*/
|
|
String_console &operator = (String_console const &);
|
|
String_console(String_console const &);
|
|
|
|
public:
|
|
|
|
/**
|
|
* Constructor
|
|
*
|
|
* \param dst destination character buffer
|
|
* \param dst_len size of 'dst'
|
|
*/
|
|
String_console(char *dst, size_t dst_len)
|
|
: _dst(dst), _dst_len(dst_len)
|
|
{ _dst[0] = 0; }
|
|
|
|
/**
|
|
* Return number of characters in destination buffer
|
|
*/
|
|
size_t len() { return _w_offset; }
|
|
|
|
|
|
/***********************
|
|
** Console interface **
|
|
***********************/
|
|
|
|
void _out_char(char c) override
|
|
{
|
|
/* ensure to leave space for null-termination */
|
|
if (_w_offset + 2 > _dst_len)
|
|
return;
|
|
|
|
_dst[_w_offset++] = c;
|
|
_dst[_w_offset] = 0;
|
|
}
|
|
};
|
|
|
|
|
|
inline Format::size_t Format::snprintf(char *dst, size_t dst_len, const char *format, ...)
|
|
{
|
|
va_list list;
|
|
va_start(list, format);
|
|
|
|
String_console sc(dst, dst_len);
|
|
sc.vprintf(format, list);
|
|
|
|
va_end(list);
|
|
return sc.len();
|
|
}
|
|
|
|
#endif /* _INCLUDE__FORMAT__SNPRINTF_H_ */
|