kc3-lang/gnulib/tests/test-term-style-control-yes.c

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• Hash : 32a72f45
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  Date : 2023-01-01T01:14:21
  

  maint: run 'make update-copyright'
  

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• tests/test-term-style-control-yes.c

• /* 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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