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Commit | Line | Data |
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1968a360 LP |
1 | /*** |
2 | This file is part of systemd. | |
3 | ||
4 | Copyright 2010 Lennart Poettering | |
5 | ||
6 | systemd is free software; you can redistribute it and/or modify it | |
5430f7f2 LP |
7 | under the terms of the GNU Lesser General Public License as published by |
8 | the Free Software Foundation; either version 2.1 of the License, or | |
1968a360 LP |
9 | (at your option) any later version. |
10 | ||
11 | systemd is distributed in the hope that it will be useful, but | |
12 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
5430f7f2 | 14 | Lesser General Public License for more details. |
1968a360 | 15 | |
5430f7f2 | 16 | You should have received a copy of the GNU Lesser General Public License |
1968a360 LP |
17 | along with systemd; If not, see <http://www.gnu.org/licenses/>. |
18 | ***/ | |
19 | ||
a8fbdf54 TA |
20 | #include <errno.h> |
21 | #include <signal.h> | |
22 | #include <stddef.h> | |
23 | #include <stdint.h> | |
24 | #include <stdio.h> | |
1968a360 | 25 | #include <stdlib.h> |
1968a360 LP |
26 | #include <string.h> |
27 | #include <sys/prctl.h> | |
07630cea | 28 | #include <unistd.h> |
1968a360 | 29 | |
07630cea | 30 | #include "copy.h" |
3ffd4af2 | 31 | #include "fd-util.h" |
8752c575 | 32 | #include "locale-util.h" |
a8fbdf54 | 33 | #include "log.h" |
1968a360 | 34 | #include "macro.h" |
3ffd4af2 | 35 | #include "pager.h" |
07630cea | 36 | #include "process-util.h" |
ce30c8dc | 37 | #include "signal-util.h" |
07630cea | 38 | #include "string-util.h" |
57c9e047 | 39 | #include "strv.h" |
07630cea | 40 | #include "terminal-util.h" |
1968a360 LP |
41 | |
42 | static pid_t pager_pid = 0; | |
43 | ||
919ce0b7 | 44 | noreturn static void pager_fallback(void) { |
6a7c676c | 45 | int r; |
46e65dcc | 46 | |
1c876927 | 47 | r = copy_bytes(STDIN_FILENO, STDOUT_FILENO, (uint64_t) -1, 0); |
6a7c676c LP |
48 | if (r < 0) { |
49 | log_error_errno(r, "Internal pager failed: %m"); | |
4a8e40eb MS |
50 | _exit(EXIT_FAILURE); |
51 | } | |
46e65dcc | 52 | |
4a8e40eb MS |
53 | _exit(EXIT_SUCCESS); |
54 | } | |
55 | ||
a45e7bb4 MS |
56 | static int stored_stdout = -1; |
57 | static int stored_stderr = -1; | |
58 | static bool stdout_redirected = false; | |
59 | static bool stderr_redirected = false; | |
60 | ||
ea4b98e6 | 61 | int pager_open(bool no_pager, bool jump_to_end) { |
bcbd61db | 62 | _cleanup_close_pair_ int fd[2] = { -1, -1 }; |
1968a360 LP |
63 | const char *pager; |
64 | pid_t parent_pid; | |
65 | ||
ea4b98e6 AK |
66 | if (no_pager) |
67 | return 0; | |
68 | ||
1968a360 | 69 | if (pager_pid > 0) |
f89a3b6f | 70 | return 1; |
1968a360 | 71 | |
ac96418b | 72 | if (terminal_is_dumb()) |
f89a3b6f | 73 | return 0; |
729e3769 | 74 | |
bcbd61db LP |
75 | pager = getenv("SYSTEMD_PAGER"); |
76 | if (!pager) | |
77 | pager = getenv("PAGER"); | |
78 | ||
79 | /* If the pager is explicitly turned off, honour it */ | |
57c9e047 | 80 | if (pager && STR_IN_SET(pager, "", "cat")) |
bcbd61db LP |
81 | return 0; |
82 | ||
1968a360 LP |
83 | /* Determine and cache number of columns before we spawn the |
84 | * pager so that we get the value from the actual tty */ | |
bcbd61db | 85 | (void) columns(); |
1968a360 | 86 | |
d262e99e | 87 | if (pipe2(fd, O_CLOEXEC) < 0) |
4a62c710 | 88 | return log_error_errno(errno, "Failed to create pager pipe: %m"); |
1968a360 | 89 | |
df0ff127 | 90 | parent_pid = getpid_cached(); |
1968a360 LP |
91 | |
92 | pager_pid = fork(); | |
bcbd61db | 93 | if (pager_pid < 0) |
65359589 | 94 | return log_error_errno(errno, "Failed to fork pager: %m"); |
1968a360 LP |
95 | |
96 | /* In the child start the pager */ | |
97 | if (pager_pid == 0) { | |
a1b4e6e9 | 98 | const char* less_opts, *less_charset; |
1968a360 | 99 | |
ce30c8dc LP |
100 | (void) reset_all_signal_handlers(); |
101 | (void) reset_signal_mask(); | |
102 | ||
bcbd61db | 103 | (void) dup2(fd[0], STDIN_FILENO); |
3d94f76c | 104 | safe_close_pair(fd); |
1968a360 | 105 | |
a1b4e6e9 | 106 | /* Initialize a good set of less options */ |
f366d58d JD |
107 | less_opts = getenv("SYSTEMD_LESS"); |
108 | if (!less_opts) | |
109 | less_opts = "FRSXMK"; | |
1b12a7b5 | 110 | if (jump_to_end) |
63c372cb | 111 | less_opts = strjoina(less_opts, " +G"); |
0357fa0d ZJS |
112 | if (setenv("LESS", less_opts, 1) < 0) |
113 | _exit(EXIT_FAILURE); | |
1968a360 | 114 | |
a1b4e6e9 LP |
115 | /* Initialize a good charset for less. This is |
116 | * particularly important if we output UTF-8 | |
117 | * characters. */ | |
118 | less_charset = getenv("SYSTEMD_LESSCHARSET"); | |
119 | if (!less_charset && is_locale_utf8()) | |
120 | less_charset = "utf-8"; | |
0357fa0d ZJS |
121 | if (less_charset && |
122 | setenv("LESSCHARSET", less_charset, 1) < 0) | |
123 | _exit(EXIT_FAILURE); | |
a1b4e6e9 | 124 | |
1968a360 LP |
125 | /* Make sure the pager goes away when the parent dies */ |
126 | if (prctl(PR_SET_PDEATHSIG, SIGTERM) < 0) | |
127 | _exit(EXIT_FAILURE); | |
128 | ||
129 | /* Check whether our parent died before we were able | |
130 | * to set the death signal */ | |
131 | if (getppid() != parent_pid) | |
132 | _exit(EXIT_SUCCESS); | |
133 | ||
134 | if (pager) { | |
135 | execlp(pager, pager, NULL); | |
136 | execl("/bin/sh", "sh", "-c", pager, NULL); | |
137 | } | |
138 | ||
139 | /* Debian's alternatives command for pagers is | |
140 | * called 'pager'. Note that we do not call | |
141 | * sensible-pagers here, since that is just a | |
142 | * shell script that implements a logic that | |
143 | * is similar to this one anyway, but is | |
144 | * Debian-specific. */ | |
145 | execlp("pager", "pager", NULL); | |
146 | ||
147 | execlp("less", "less", NULL); | |
148 | execlp("more", "more", NULL); | |
1968a360 | 149 | |
4a8e40eb MS |
150 | pager_fallback(); |
151 | /* not reached */ | |
1968a360 LP |
152 | } |
153 | ||
154 | /* Return in the parent */ | |
a45e7bb4 MS |
155 | stored_stdout = fcntl(STDOUT_FILENO, F_DUPFD_CLOEXEC, 3); |
156 | if (dup2(fd[1], STDOUT_FILENO) < 0) { | |
157 | stored_stdout = safe_close(stored_stdout); | |
4a62c710 | 158 | return log_error_errno(errno, "Failed to duplicate pager pipe: %m"); |
a45e7bb4 MS |
159 | } |
160 | stdout_redirected = true; | |
161 | ||
162 | stored_stderr = fcntl(STDERR_FILENO, F_DUPFD_CLOEXEC, 3); | |
163 | if (dup2(fd[1], STDERR_FILENO) < 0) { | |
164 | stored_stderr = safe_close(stored_stderr); | |
8b5264aa | 165 | return log_error_errno(errno, "Failed to duplicate pager pipe: %m"); |
a45e7bb4 MS |
166 | } |
167 | stderr_redirected = true; | |
1968a360 | 168 | |
f89a3b6f | 169 | return 1; |
1968a360 LP |
170 | } |
171 | ||
172 | void pager_close(void) { | |
173 | ||
174 | if (pager_pid <= 0) | |
175 | return; | |
176 | ||
177 | /* Inform pager that we are done */ | |
a45e7bb4 | 178 | (void) fflush(stdout); |
77018a8c MS |
179 | if (stdout_redirected) |
180 | if (stored_stdout < 0 || dup2(stored_stdout, STDOUT_FILENO) < 0) | |
181 | (void) close(STDOUT_FILENO); | |
a45e7bb4 MS |
182 | stored_stdout = safe_close(stored_stdout); |
183 | (void) fflush(stderr); | |
77018a8c MS |
184 | if (stderr_redirected) |
185 | if (stored_stderr < 0 || dup2(stored_stderr, STDERR_FILENO) < 0) | |
186 | (void) close(STDERR_FILENO); | |
a45e7bb4 MS |
187 | stored_stderr = safe_close(stored_stderr); |
188 | stdout_redirected = stderr_redirected = false; | |
8b5264aa | 189 | |
74ca738f | 190 | (void) kill(pager_pid, SIGCONT); |
c73d180d | 191 | (void) wait_for_terminate(pager_pid, NULL); |
1968a360 LP |
192 | pager_pid = 0; |
193 | } | |
f89a3b6f LP |
194 | |
195 | bool pager_have(void) { | |
196 | return pager_pid > 0; | |
197 | } | |
78002a67 ZJS |
198 | |
199 | int show_man_page(const char *desc, bool null_stdio) { | |
200 | const char *args[4] = { "man", NULL, NULL, NULL }; | |
201 | char *e = NULL; | |
202 | pid_t pid; | |
203 | size_t k; | |
204 | int r; | |
205 | siginfo_t status; | |
206 | ||
207 | k = strlen(desc); | |
208 | ||
209 | if (desc[k-1] == ')') | |
210 | e = strrchr(desc, '('); | |
211 | ||
212 | if (e) { | |
213 | char *page = NULL, *section = NULL; | |
214 | ||
215 | page = strndupa(desc, e - desc); | |
216 | section = strndupa(e + 1, desc + k - e - 2); | |
217 | ||
218 | args[1] = section; | |
219 | args[2] = page; | |
220 | } else | |
221 | args[1] = desc; | |
222 | ||
223 | pid = fork(); | |
4a62c710 MS |
224 | if (pid < 0) |
225 | return log_error_errno(errno, "Failed to fork: %m"); | |
78002a67 ZJS |
226 | |
227 | if (pid == 0) { | |
228 | /* Child */ | |
ce30c8dc LP |
229 | |
230 | (void) reset_all_signal_handlers(); | |
231 | (void) reset_signal_mask(); | |
232 | ||
78002a67 ZJS |
233 | if (null_stdio) { |
234 | r = make_null_stdio(); | |
235 | if (r < 0) { | |
da927ba9 | 236 | log_error_errno(r, "Failed to kill stdio: %m"); |
78002a67 ZJS |
237 | _exit(EXIT_FAILURE); |
238 | } | |
239 | } | |
240 | ||
241 | execvp(args[0], (char**) args); | |
56f64d95 | 242 | log_error_errno(errno, "Failed to execute man: %m"); |
78002a67 ZJS |
243 | _exit(EXIT_FAILURE); |
244 | } | |
245 | ||
246 | r = wait_for_terminate(pid, &status); | |
247 | if (r < 0) | |
248 | return r; | |
249 | ||
250 | log_debug("Exit code %i status %i", status.si_code, status.si_status); | |
251 | return status.si_status; | |
252 | } |