]>
Commit | Line | Data |
---|---|---|
1968a360 LP |
1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2010 Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
5430f7f2 LP |
9 | under the terms of the GNU Lesser General Public License as published by |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
1968a360 LP |
11 | (at your option) any later version. |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
5430f7f2 | 16 | Lesser General Public License for more details. |
1968a360 | 17 | |
5430f7f2 | 18 | You should have received a copy of the GNU Lesser General Public License |
1968a360 LP |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. |
20 | ***/ | |
21 | ||
4a8e40eb | 22 | #include <fcntl.h> |
1968a360 | 23 | #include <stdlib.h> |
1968a360 LP |
24 | #include <string.h> |
25 | #include <sys/prctl.h> | |
07630cea | 26 | #include <unistd.h> |
1968a360 | 27 | |
07630cea | 28 | #include "copy.h" |
1968a360 | 29 | #include "macro.h" |
07630cea | 30 | #include "process-util.h" |
ce30c8dc | 31 | #include "signal-util.h" |
07630cea LP |
32 | #include "string-util.h" |
33 | #include "terminal-util.h" | |
34 | #include "util.h" | |
35 | #include "pager.h" | |
1968a360 LP |
36 | |
37 | static pid_t pager_pid = 0; | |
38 | ||
919ce0b7 | 39 | noreturn static void pager_fallback(void) { |
6a7c676c | 40 | int r; |
46e65dcc | 41 | |
59f448cf | 42 | r = copy_bytes(STDIN_FILENO, STDOUT_FILENO, (uint64_t) -1, false); |
6a7c676c LP |
43 | if (r < 0) { |
44 | log_error_errno(r, "Internal pager failed: %m"); | |
4a8e40eb MS |
45 | _exit(EXIT_FAILURE); |
46 | } | |
46e65dcc | 47 | |
4a8e40eb MS |
48 | _exit(EXIT_SUCCESS); |
49 | } | |
50 | ||
1b12a7b5 | 51 | int pager_open(bool jump_to_end) { |
bcbd61db | 52 | _cleanup_close_pair_ int fd[2] = { -1, -1 }; |
1968a360 LP |
53 | const char *pager; |
54 | pid_t parent_pid; | |
55 | ||
56 | if (pager_pid > 0) | |
f89a3b6f | 57 | return 1; |
1968a360 | 58 | |
8481248b | 59 | if (!on_tty()) |
f89a3b6f | 60 | return 0; |
729e3769 | 61 | |
bcbd61db LP |
62 | pager = getenv("SYSTEMD_PAGER"); |
63 | if (!pager) | |
64 | pager = getenv("PAGER"); | |
65 | ||
66 | /* If the pager is explicitly turned off, honour it */ | |
67 | if (pager && (pager[0] == 0 || streq(pager, "cat"))) | |
68 | return 0; | |
69 | ||
1968a360 LP |
70 | /* Determine and cache number of columns before we spawn the |
71 | * pager so that we get the value from the actual tty */ | |
bcbd61db | 72 | (void) columns(); |
1968a360 | 73 | |
4a62c710 MS |
74 | if (pipe(fd) < 0) |
75 | return log_error_errno(errno, "Failed to create pager pipe: %m"); | |
1968a360 LP |
76 | |
77 | parent_pid = getpid(); | |
78 | ||
79 | pager_pid = fork(); | |
bcbd61db | 80 | if (pager_pid < 0) |
65359589 | 81 | return log_error_errno(errno, "Failed to fork pager: %m"); |
1968a360 LP |
82 | |
83 | /* In the child start the pager */ | |
84 | if (pager_pid == 0) { | |
a1b4e6e9 | 85 | const char* less_opts, *less_charset; |
1968a360 | 86 | |
ce30c8dc LP |
87 | (void) reset_all_signal_handlers(); |
88 | (void) reset_signal_mask(); | |
89 | ||
bcbd61db | 90 | (void) dup2(fd[0], STDIN_FILENO); |
3d94f76c | 91 | safe_close_pair(fd); |
1968a360 | 92 | |
a1b4e6e9 | 93 | /* Initialize a good set of less options */ |
f366d58d JD |
94 | less_opts = getenv("SYSTEMD_LESS"); |
95 | if (!less_opts) | |
96 | less_opts = "FRSXMK"; | |
1b12a7b5 | 97 | if (jump_to_end) |
63c372cb | 98 | less_opts = strjoina(less_opts, " +G"); |
f366d58d | 99 | setenv("LESS", less_opts, 1); |
1968a360 | 100 | |
a1b4e6e9 LP |
101 | /* Initialize a good charset for less. This is |
102 | * particularly important if we output UTF-8 | |
103 | * characters. */ | |
104 | less_charset = getenv("SYSTEMD_LESSCHARSET"); | |
105 | if (!less_charset && is_locale_utf8()) | |
106 | less_charset = "utf-8"; | |
107 | if (less_charset) | |
108 | setenv("LESSCHARSET", less_charset, 1); | |
109 | ||
1968a360 LP |
110 | /* Make sure the pager goes away when the parent dies */ |
111 | if (prctl(PR_SET_PDEATHSIG, SIGTERM) < 0) | |
112 | _exit(EXIT_FAILURE); | |
113 | ||
114 | /* Check whether our parent died before we were able | |
115 | * to set the death signal */ | |
116 | if (getppid() != parent_pid) | |
117 | _exit(EXIT_SUCCESS); | |
118 | ||
119 | if (pager) { | |
120 | execlp(pager, pager, NULL); | |
121 | execl("/bin/sh", "sh", "-c", pager, NULL); | |
122 | } | |
123 | ||
124 | /* Debian's alternatives command for pagers is | |
125 | * called 'pager'. Note that we do not call | |
126 | * sensible-pagers here, since that is just a | |
127 | * shell script that implements a logic that | |
128 | * is similar to this one anyway, but is | |
129 | * Debian-specific. */ | |
130 | execlp("pager", "pager", NULL); | |
131 | ||
132 | execlp("less", "less", NULL); | |
133 | execlp("more", "more", NULL); | |
1968a360 | 134 | |
4a8e40eb MS |
135 | pager_fallback(); |
136 | /* not reached */ | |
1968a360 LP |
137 | } |
138 | ||
139 | /* Return in the parent */ | |
4a62c710 MS |
140 | if (dup2(fd[1], STDOUT_FILENO) < 0) |
141 | return log_error_errno(errno, "Failed to duplicate pager pipe: %m"); | |
8b5264aa LP |
142 | if (dup2(fd[1], STDERR_FILENO) < 0) |
143 | return log_error_errno(errno, "Failed to duplicate pager pipe: %m"); | |
1968a360 | 144 | |
f89a3b6f | 145 | return 1; |
1968a360 LP |
146 | } |
147 | ||
148 | void pager_close(void) { | |
149 | ||
150 | if (pager_pid <= 0) | |
151 | return; | |
152 | ||
153 | /* Inform pager that we are done */ | |
74ca738f LP |
154 | stdout = safe_fclose(stdout); |
155 | stderr = safe_fclose(stderr); | |
8b5264aa | 156 | |
74ca738f | 157 | (void) kill(pager_pid, SIGCONT); |
c73d180d | 158 | (void) wait_for_terminate(pager_pid, NULL); |
1968a360 LP |
159 | pager_pid = 0; |
160 | } | |
f89a3b6f LP |
161 | |
162 | bool pager_have(void) { | |
163 | return pager_pid > 0; | |
164 | } | |
78002a67 ZJS |
165 | |
166 | int show_man_page(const char *desc, bool null_stdio) { | |
167 | const char *args[4] = { "man", NULL, NULL, NULL }; | |
168 | char *e = NULL; | |
169 | pid_t pid; | |
170 | size_t k; | |
171 | int r; | |
172 | siginfo_t status; | |
173 | ||
174 | k = strlen(desc); | |
175 | ||
176 | if (desc[k-1] == ')') | |
177 | e = strrchr(desc, '('); | |
178 | ||
179 | if (e) { | |
180 | char *page = NULL, *section = NULL; | |
181 | ||
182 | page = strndupa(desc, e - desc); | |
183 | section = strndupa(e + 1, desc + k - e - 2); | |
184 | ||
185 | args[1] = section; | |
186 | args[2] = page; | |
187 | } else | |
188 | args[1] = desc; | |
189 | ||
190 | pid = fork(); | |
4a62c710 MS |
191 | if (pid < 0) |
192 | return log_error_errno(errno, "Failed to fork: %m"); | |
78002a67 ZJS |
193 | |
194 | if (pid == 0) { | |
195 | /* Child */ | |
ce30c8dc LP |
196 | |
197 | (void) reset_all_signal_handlers(); | |
198 | (void) reset_signal_mask(); | |
199 | ||
78002a67 ZJS |
200 | if (null_stdio) { |
201 | r = make_null_stdio(); | |
202 | if (r < 0) { | |
da927ba9 | 203 | log_error_errno(r, "Failed to kill stdio: %m"); |
78002a67 ZJS |
204 | _exit(EXIT_FAILURE); |
205 | } | |
206 | } | |
207 | ||
208 | execvp(args[0], (char**) args); | |
56f64d95 | 209 | log_error_errno(errno, "Failed to execute man: %m"); |
78002a67 ZJS |
210 | _exit(EXIT_FAILURE); |
211 | } | |
212 | ||
213 | r = wait_for_terminate(pid, &status); | |
214 | if (r < 0) | |
215 | return r; | |
216 | ||
217 | log_debug("Exit code %i status %i", status.si_code, status.si_status); | |
218 | return status.si_status; | |
219 | } |