| /* |
| * 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; |
| } |
| } |