/usr/share/doc/libglibmm-2.4-dev/examples/iochannel_stream/fdstream.cc is in libglibmm-2.4-doc 2.56.0-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 | /* Copyright (C) 2004 The glibmm Development Team
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include "fdstream.h"
#include <glibmm/main.h>
fdstreambuf::fdstreambuf()
{
reset();
}
fdstreambuf::fdstreambuf(int fd, bool manage)
{
create_iochannel(fd, manage);
}
fdstreambuf::~fdstreambuf()
{
sync();
}
void
fdstreambuf::reset()
{
setg(putback_buffer + 1, putback_buffer + 1, putback_buffer + 1);
error_condition.error = false;
}
void
fdstreambuf::create_iochannel(int fd, bool manage)
{
sync();
reset();
if (fd >= 0)
{
iochannel_ = Glib::IOChannel::create_from_fd(fd);
iochannel_->set_encoding("");
iochannel_->set_buffered(true);
iochannel_->set_close_on_unref(manage);
}
}
void
fdstreambuf::detach_fd()
{
iochannel_->set_close_on_unref(false);
}
void
fdstreambuf::connect(
const sigc::slot<bool(Glib::IOCondition)>& callback, Glib::IOCondition condition)
{
Glib::signal_io().connect(callback, iochannel_, condition);
}
fdstream_error
fdstreambuf::get_error() const
{
return error_condition;
}
// the standard requires sync to return 0 for success and -1 for error
int
fdstreambuf::sync()
{
if (!iochannel_)
return -1;
try
{
iochannel_->flush();
}
catch (Glib::IOChannelError& io_error)
{
error_condition.error = true;
error_condition.code = io_error.code();
return -1;
}
return 0;
}
void
fdstreambuf::close_iochannel()
{
iochannel_->set_close_on_unref(false);
reset();
try
{
iochannel_->close(true);
}
catch (Glib::IOChannelError& io_error)
{
error_condition.error = true;
error_condition.code = io_error.code();
}
}
// the standard requires this to return either the character
// written on overflow or traits_type::eof() (= EOF with char_type == char)
fdstreambuf::traits_type::int_type
fdstreambuf::overflow(int_type c)
{
if (!traits_type::eq_int_type(c, traits_type::eof()))
{
try
{
gsize result = 0;
char write_char = c;
iochannel_->write(&write_char, 1, result);
}
catch (Glib::IOChannelError& io_error)
{
error_condition.error = true;
error_condition.code = io_error.code();
return traits_type::eof();
}
}
return traits_type::not_eof(c);
}
// the standard requires this to return the number of characters written
// (which will be 0 for stream failure - it is not correct to return EOF)
std::streamsize
fdstreambuf::xsputn(const char* source, std::streamsize num)
{
gsize result = 0;
// the documentation for Glib::IOChannel indicates that Glib::IOChannel::write()
// will only do a short write in the event of stream failure, so there is no
// need to check result and have a second bite (byte) at it as would be
// necessary with Unix write()
try
{
iochannel_->write(source, num, result);
}
catch (Glib::IOChannelError& io_error)
{
error_condition.error = true;
error_condition.code = io_error.code();
result = 0;
}
return result;
}
// the standard requires this to return the first character available
// on underflow or traits_type::eof() (= EOF with char_type == char)
fdstreambuf::traits_type::int_type
fdstreambuf::underflow()
{
if (gptr() < egptr())
return traits_type::to_int_type(*gptr());
// copy the character in bump position (if any) to putback position
if (gptr() - eback())
*putback_buffer = *(gptr() - 1);
// now insert a character into the bump position
gsize result = 0;
try
{
iochannel_->read(putback_buffer + 1, 1, result);
}
catch (Glib::IOChannelError& io_error)
{
error_condition.error = true;
error_condition.code = io_error.code();
return traits_type::eof();
}
// some other error - is this possible? In case it is, cater for it
if (result == 0)
return traits_type::eof();
// reset buffer pointers
setg(putback_buffer, putback_buffer + 1, putback_buffer + 2);
// return character in bump/peek position
return traits_type::to_int_type(*gptr()); // == *(putback_buffer + 1)
}
// the standard requires this to return the number of characters fetched
// (which will be 0 for stream failure - it is not correct to return EOF)
std::streamsize
fdstreambuf::xsgetn(char* dest, std::streamsize num)
{
std::streamsize chars_read = 0;
// available would normally be 0, but could be up to 2 if there
// have been putbacks or a peek and a putback
std::streamsize available = egptr() - gptr();
// if num is less than or equal to the characters already in the
// putback buffer, extract from buffer
if (num <= available)
{
traits_type::copy(dest, gptr(), num);
gbump(num);
chars_read = num;
}
else
{
// first copy out putback buffer
if (available)
{
traits_type::copy(dest, gptr(), available);
chars_read = available;
}
// read up to everything else we need with Glib::IOChannel::read()
gsize result = 0;
try
{
do
{
iochannel_->read(dest + chars_read, num - chars_read, result);
if (result > 0)
chars_read += result;
} while (result > 0 && result < static_cast<gsize>(num - chars_read));
}
catch (Glib::IOChannelError& io_error)
{
error_condition.error = true;
error_condition.code = io_error.code();
return chars_read;
}
if (chars_read)
{
// now mimic extraction of all characters by sbumpc() by putting
// two characters into the buffer (if available) and resetting the
// buffer pointers
int putback_count = 0;
if (chars_read >= 2)
{
*putback_buffer = *(dest + (chars_read - 2));
putback_count = 2;
}
else
{ // if we have reached here then we have only fetched
// one character and it must have been read with
// Glib::IOChannel::read() and not taken from the
// putback buffer - otherwise we would have ended
// at the first if block in this method
// - and this also means that gptr() == egptr()
if (gptr() - eback())
{
*putback_buffer = *(gptr() - 1);
putback_count = 2;
}
else
putback_count = 1;
}
*(putback_buffer + 1) = *(dest + (chars_read - 1));
// reset buffer pointers
this->setg(putback_buffer + (2 - putback_count), putback_buffer + 2, putback_buffer + 2);
}
}
return chars_read;
}
fdstream::fdstream(int fd, bool manage)
: std::istream(nullptr), std::ostream(nullptr), buf(fd, manage)
{
std::istream::rdbuf(&buf);
std::ostream::rdbuf(&buf);
}
fdstream::fdstream() : std::istream(nullptr), std::ostream(nullptr)
{
std::istream::rdbuf(&buf);
std::ostream::rdbuf(&buf);
}
void
fdstream::attach(int fd, bool manage)
{
buf.create_iochannel(fd, manage);
}
void
fdstream::detach()
{
buf.detach_fd();
}
void
fdstream::close()
{
buf.close_iochannel();
}
void
fdstream::connect(const sigc::slot<bool(Glib::IOCondition)>& callback, Glib::IOCondition condition)
{
buf.connect(callback, condition);
}
fdstream_error
fdstream::get_error() const
{
return buf.get_error();
}
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