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d2b1a04737
now that _GNU_SOURCE definition is in config.h we want to make sure that all headers that are included know about it
126 lines
3.3 KiB
C
126 lines
3.3 KiB
C
/* Copyright (c) 2013
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* Mike Gerwitz (mtg@gnu.org)
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*
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* This file is part of GNU screen.
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*
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* GNU screen is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 3, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program (see the file COPYING); if not, see
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* <http://www.gnu.org/licenses>.
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*
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****************************************************************
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*/
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#include "config.h"
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#include "winmsgcond.h"
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#include <assert.h>
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#include <stdlib.h>
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/* Initialize new condition and set to false; can be used to re-initialize a
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* condition for re-use */
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void wmc_init(WinMsgCond *cond, char *pos)
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{
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cond->locked = false;
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cond->pos = pos;
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wmc_clear(cond);
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}
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/* Mark condition as true */
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void wmc_set(WinMsgCond *cond)
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{
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if (cond->locked)
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return;
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cond->state = true;
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}
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/* Clear condition (equivalent to non-match) */
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void wmc_clear(WinMsgCond *cond)
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{
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if (cond->locked)
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return;
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cond->state = false;
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}
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/* Determine if condition is active (has been initialized and can be used) */
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bool wmc_is_active(const WinMsgCond *cond)
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{
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return (cond->pos != NULL);
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}
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/* Determine if a condition is true; the result is undefined if
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* !wmc_active(cond) */
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bool wmc_is_set(const WinMsgCond *cond)
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{
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return cond->state;
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}
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/* "else" encounted */
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char *wmc_else(WinMsgCond *cond, char *pos, bool *changed)
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{
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assert(wmc_is_active(cond));
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/* if we're already set, then there is no point in processing the "else";
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* we will therefore consider the previous condition to have succeeded, so
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* now keep track of the start of the else so that it may be clobbered
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* instead of the beginning of the true condition---that is, we're accepting
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* the destination string up until this point */
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if (wmc_is_set(cond)) {
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wmc_init(cond, pos); /* track this as a new condition */
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cond->locked = true; /* "else" shall never succeed at this point */
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/* we want to keep the string we have so far (the truth string) */
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if (changed)
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*changed = false;
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return pos;
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}
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/* now that we have reached "else" and are not true, we can never be true;
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* discard the truth part of the string */
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char *prevpos = cond->pos;
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cond->pos = pos;
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/* the "else" part must always be true at this point, because the previous
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* condition failed */
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wmc_set(cond);
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cond->locked = true;
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if (changed)
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*changed = true;
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return prevpos;
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}
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/* End condition and determine if string should be reset or kept---if our value
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* is truthful, then accept the string, otherwise reject and reset to the
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* position that we were initialized with */
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char *wmc_end(const WinMsgCond *cond, char *pos, bool *changed)
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{
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bool set = wmc_is_set(cond);
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if (changed)
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*changed = !set;
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return (set) ? pos : cond->pos;
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}
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/* Deactivate a condition, preventing its use; this allows a single allocation
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* to be re-used and ignored until activated */
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void wmc_deinit(WinMsgCond *cond)
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{
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cond->state = false;
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cond->pos = NULL;
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cond->locked = true;
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}
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