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