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/* Interactive test program for the term-style-control module.
Copyright (C) 2019-2023 Free Software Foundation, Inc.
Written by Bruno Haible <bruno@clisp.org>, 2019.
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 3 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, see <https://www.gnu.org/licenses/>. */
#include <config.h>
/* Specification. */
#include "term-style-control.h"
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "full-write.h"
/* This program outputs an endless amount of lines, each consisting of a
single 'y', in red color and underlined.
It can be used to exercise race conditions caused by
- simultaneous keyboard input on the terminal,
- pressing Ctrl-C,
- pressing Ctrl-Z and then "fg". */
/* ECMA-48 / ISO 6429 escape sequences. See
https://en.wikipedia.org/wiki/ANSI_escape_code#SGR_(Select_Graphic_Rendition)_parameters
*/
static const char set_underline_on[] = "\033[4m";
static const char set_underline_off[] = "\033[24m";
static const char set_foreground_color_red[] = "\033[31m";
static const char set_foreground_color_default[] = "\033[39m";
struct term_style_user_data
{
/* This field is marked volatile, because it is accessed from the
async-safe function async_set_attributes_from_default. */
bool volatile red_and_underline;
struct term_style_control_data ctrl_data;
};
static struct term_style_control_data *
get_control_data (struct term_style_user_data *user_data)
{
return &user_data->ctrl_data;
}
static void
restore (struct term_style_user_data *user_data)
{
fputs (set_underline_off, stdout);
fputs (set_foreground_color_default, stdout);
fflush (stdout);
}
static _GL_ASYNC_SAFE void
async_restore (struct term_style_user_data *user_data)
{
/* No <stdio.h> calls here! */
full_write (STDOUT_FILENO, set_underline_off,
strlen (set_underline_off));
full_write (STDOUT_FILENO, set_foreground_color_default,
strlen (set_foreground_color_default));
}
static _GL_ASYNC_SAFE void
async_set_attributes_from_default (struct term_style_user_data *user_data)
{
/* No <stdio.h> calls here! */
if (user_data->red_and_underline)
{
full_write (STDOUT_FILENO, set_underline_on,
strlen (set_underline_on));
full_write (STDOUT_FILENO, set_foreground_color_red,
strlen (set_foreground_color_red));
}
}
static const struct term_style_controller controller =
{
get_control_data,
restore,
async_restore,
async_set_attributes_from_default
};
int
main (int argc, char *argv[])
{
struct term_style_user_data user_data;
/* Initialization. */
user_data.red_and_underline = false;
activate_term_style_controller (&controller, &user_data, STDOUT_FILENO,
TTYCTL_AUTO);
for (;;)
{
/* Before any styling, enable the non-default mode. */
activate_term_non_default_mode (&controller, &user_data);
/* Set user_data.red_and_underline *before* emitting the appropriate
escape sequences, otherwise async_set_attributes_from_default will not
do its job correctly. */
user_data.red_and_underline = true;
fputs (set_underline_on, stdout);
fputs (set_foreground_color_red, stdout);
fflush (stdout);
fputs ("y", stdout);
fflush (stdout);
/* Revert to the default style before emitting a newline. */
user_data.red_and_underline = false;
fputs (set_underline_off, stdout);
fputs (set_foreground_color_default, stdout);
fflush (stdout);
/* Optional. */
deactivate_term_non_default_mode (&controller, &user_data);
fputs ("\n", stdout);
fflush (stdout);
}
}
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