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/*
* Copyright (c) 2018 Rob Clark <robdclark@gmail.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <errno.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include "pager.h"
static pid_t pager_pid;
static void
pager_death(int n)
{
exit(0);
}
void
pager_open(void)
{
int fd[2];
if (pipe(fd) < 0) {
fprintf(stderr, "Failed to create pager pipe: %m\n");
exit(-1);
}
pager_pid = fork();
if (pager_pid < 0) {
fprintf(stderr, "Failed to fork pager: %m\n");
exit(-1);
}
if (pager_pid == 0) {
const char* less_opts;
dup2(fd[0], STDIN_FILENO);
close(fd[0]);
close(fd[1]);
less_opts = "FRSMKX";
setenv("LESS", less_opts, 1);
execlp("less", "less", NULL);
} else {
/* we want to kill the parent process when pager exits: */
signal(SIGCHLD, pager_death);
dup2(fd[1], STDOUT_FILENO);
close(fd[0]);
close(fd[1]);
}
}
int
pager_close(void)
{
siginfo_t status;
close(STDOUT_FILENO);
while (true) {
memset(&status, 0, sizeof(status));
if (waitid(P_PID, pager_pid, &status, WEXITED) < 0) {
if (errno == EINTR)
continue;
return -errno;
}
return 0;
}
}
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