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/*
*
* BlueZ - Bluetooth protocol stack for Linux
*
* Copyright (C) 2011-2014 Intel Corporation
* Copyright (C) 2002-2010 Marcel Holtmann <marcel@holtmann.org>
*
*
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <sys/wait.h>
#include <sys/prctl.h>
#include <sys/ioctl.h>
#include <termios.h>
#include "display.h"
static pid_t pager_pid = 0;
bool use_color(void)
{
static int cached_use_color = -1;
if (__builtin_expect(!!(cached_use_color < 0), 0))
cached_use_color = isatty(STDOUT_FILENO) > 0 || pager_pid > 0;
return cached_use_color;
}
int num_columns(void)
{
static int cached_num_columns = -1;
if (__builtin_expect(!!(cached_num_columns < 0), 0)) {
struct winsize ws;
if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) < 0 ||
ws.ws_col == 0)
cached_num_columns = FALLBACK_TERMINAL_WIDTH;
else
cached_num_columns = ws.ws_col;
}
return cached_num_columns;
}
static void close_pipe(int p[])
{
if (p[0] >= 0)
close(p[0]);
if (p[1] >= 0)
close(p[1]);
}
static void wait_for_terminate(pid_t pid)
{
siginfo_t dummy;
for (;;) {
memset(&dummy, 0, sizeof(dummy));
if (waitid(P_PID, pid, &dummy, WEXITED) < 0) {
if (errno == EINTR)
continue;
return;
}
return;
}
}
void open_pager(void)
{
const char *pager;
pid_t parent_pid;
int fd[2];
if (pager_pid > 0)
return;
pager = getenv("PAGER");
if (pager) {
if (!*pager || strcmp(pager, "cat") == 0)
return;
}
if (!(isatty(STDOUT_FILENO) > 0))
return;
num_columns();
if (pipe(fd) < 0) {
perror("Failed to create pager pipe");
return;
}
parent_pid = getpid();
pager_pid = fork();
if (pager_pid < 0) {
perror("Failed to fork pager");
close_pipe(fd);
return;
}
if (pager_pid == 0) {
dup2(fd[0], STDIN_FILENO);
close_pipe(fd);
setenv("LESS", "FRSX", 0);
if (prctl(PR_SET_PDEATHSIG, SIGTERM) < 0)
_exit(EXIT_FAILURE);
if (getppid() != parent_pid)
_exit(EXIT_SUCCESS);
if (pager) {
execlp(pager, pager, NULL);
execl("/bin/sh", "sh", "-c", pager, NULL);
}
execlp("pager", "pager", NULL);
execlp("less", "less", NULL);
execlp("more", "more", NULL);
_exit(EXIT_FAILURE);
}
if (dup2(fd[1], STDOUT_FILENO) < 0) {
perror("Failed to duplicate pager pipe");
return;
}
close_pipe(fd);
}
void close_pager(void)
{
if (pager_pid <= 0)
return;
fclose(stdout);
kill(pager_pid, SIGCONT);
wait_for_terminate(pager_pid);
pager_pid = 0;
}
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