ladybird/Userland/more.cpp
Lenny Maiorani 765936ebae
Everywhere: Switch from (void) to [[maybe_unused]] (#4473)
Problem:
- `(void)` simply casts the expression to void. This is understood to
  indicate that it is ignored, but this is really a compiler trick to
  get the compiler to not generate a warning.

Solution:
- Use the `[[maybe_unused]]` attribute to indicate the value is unused.

Note:
- Functions taking a `(void)` argument list have also been changed to
  `()` because this is not needed and shows up in the same grep
  command.
2020-12-21 00:09:48 +01:00

75 lines
2.3 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <fcntl.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <unistd.h>
static int key_fd;
static void wait_for_key()
{
printf("\033[7m--[ more ]--\033[0m");
fflush(stdout);
char dummy;
[[maybe_unused]] auto rc = read(key_fd, &dummy, 1);
printf("\n");
}
int main([[maybe_unused]] int argc, [[maybe_unused]] char** argv)
{
if (pledge("stdio rpath tty", nullptr) < 0) {
perror("pledge");
return 1;
}
key_fd = STDOUT_FILENO;
struct winsize ws;
ioctl(1, TIOCGWINSZ, &ws);
if (pledge("stdio", nullptr) < 0) {
perror("pledge");
return 1;
}
unsigned lines_printed = 0;
while (!feof(stdin)) {
char buffer[BUFSIZ];
auto* str = fgets(buffer, sizeof(buffer), stdin);
if (!str)
break;
printf("%s", str);
++lines_printed;
if ((lines_printed % (ws.ws_row - 1)) == 0) {
wait_for_key();
}
}
close(key_fd);
return 0;
}