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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 | ||
ea4b98e6 | 56 | int pager_open(bool no_pager, bool jump_to_end) { |
bcbd61db | 57 | _cleanup_close_pair_ int fd[2] = { -1, -1 }; |
1968a360 LP |
58 | const char *pager; |
59 | pid_t parent_pid; | |
60 | ||
ea4b98e6 AK |
61 | if (no_pager) |
62 | return 0; | |
63 | ||
1968a360 | 64 | if (pager_pid > 0) |
f89a3b6f | 65 | return 1; |
1968a360 | 66 | |
ac96418b | 67 | if (terminal_is_dumb()) |
f89a3b6f | 68 | return 0; |
729e3769 | 69 | |
bcbd61db LP |
70 | pager = getenv("SYSTEMD_PAGER"); |
71 | if (!pager) | |
72 | pager = getenv("PAGER"); | |
73 | ||
74 | /* If the pager is explicitly turned off, honour it */ | |
57c9e047 | 75 | if (pager && STR_IN_SET(pager, "", "cat")) |
bcbd61db LP |
76 | return 0; |
77 | ||
1968a360 LP |
78 | /* Determine and cache number of columns before we spawn the |
79 | * pager so that we get the value from the actual tty */ | |
bcbd61db | 80 | (void) columns(); |
1968a360 | 81 | |
4a62c710 MS |
82 | if (pipe(fd) < 0) |
83 | return log_error_errno(errno, "Failed to create pager pipe: %m"); | |
1968a360 LP |
84 | |
85 | parent_pid = getpid(); | |
86 | ||
87 | pager_pid = fork(); | |
bcbd61db | 88 | if (pager_pid < 0) |
65359589 | 89 | return log_error_errno(errno, "Failed to fork pager: %m"); |
1968a360 LP |
90 | |
91 | /* In the child start the pager */ | |
92 | if (pager_pid == 0) { | |
a1b4e6e9 | 93 | const char* less_opts, *less_charset; |
1968a360 | 94 | |
ce30c8dc LP |
95 | (void) reset_all_signal_handlers(); |
96 | (void) reset_signal_mask(); | |
97 | ||
bcbd61db | 98 | (void) dup2(fd[0], STDIN_FILENO); |
3d94f76c | 99 | safe_close_pair(fd); |
1968a360 | 100 | |
a1b4e6e9 | 101 | /* Initialize a good set of less options */ |
f366d58d JD |
102 | less_opts = getenv("SYSTEMD_LESS"); |
103 | if (!less_opts) | |
104 | less_opts = "FRSXMK"; | |
1b12a7b5 | 105 | if (jump_to_end) |
63c372cb | 106 | less_opts = strjoina(less_opts, " +G"); |
0357fa0d ZJS |
107 | if (setenv("LESS", less_opts, 1) < 0) |
108 | _exit(EXIT_FAILURE); | |
1968a360 | 109 | |
a1b4e6e9 LP |
110 | /* Initialize a good charset for less. This is |
111 | * particularly important if we output UTF-8 | |
112 | * characters. */ | |
113 | less_charset = getenv("SYSTEMD_LESSCHARSET"); | |
114 | if (!less_charset && is_locale_utf8()) | |
115 | less_charset = "utf-8"; | |
0357fa0d ZJS |
116 | if (less_charset && |
117 | setenv("LESSCHARSET", less_charset, 1) < 0) | |
118 | _exit(EXIT_FAILURE); | |
a1b4e6e9 | 119 | |
1968a360 LP |
120 | /* Make sure the pager goes away when the parent dies */ |
121 | if (prctl(PR_SET_PDEATHSIG, SIGTERM) < 0) | |
122 | _exit(EXIT_FAILURE); | |
123 | ||
124 | /* Check whether our parent died before we were able | |
125 | * to set the death signal */ | |
126 | if (getppid() != parent_pid) | |
127 | _exit(EXIT_SUCCESS); | |
128 | ||
129 | if (pager) { | |
130 | execlp(pager, pager, NULL); | |
131 | execl("/bin/sh", "sh", "-c", pager, NULL); | |
132 | } | |
133 | ||
134 | /* Debian's alternatives command for pagers is | |
135 | * called 'pager'. Note that we do not call | |
136 | * sensible-pagers here, since that is just a | |
137 | * shell script that implements a logic that | |
138 | * is similar to this one anyway, but is | |
139 | * Debian-specific. */ | |
140 | execlp("pager", "pager", NULL); | |
141 | ||
142 | execlp("less", "less", NULL); | |
143 | execlp("more", "more", NULL); | |
1968a360 | 144 | |
4a8e40eb MS |
145 | pager_fallback(); |
146 | /* not reached */ | |
1968a360 LP |
147 | } |
148 | ||
149 | /* Return in the parent */ | |
4a62c710 MS |
150 | if (dup2(fd[1], STDOUT_FILENO) < 0) |
151 | return log_error_errno(errno, "Failed to duplicate pager pipe: %m"); | |
8b5264aa LP |
152 | if (dup2(fd[1], STDERR_FILENO) < 0) |
153 | return log_error_errno(errno, "Failed to duplicate pager pipe: %m"); | |
1968a360 | 154 | |
f89a3b6f | 155 | return 1; |
1968a360 LP |
156 | } |
157 | ||
158 | void pager_close(void) { | |
159 | ||
160 | if (pager_pid <= 0) | |
161 | return; | |
162 | ||
163 | /* Inform pager that we are done */ | |
e5276995 MS |
164 | safe_fclose(stdout); |
165 | safe_fclose(stderr); | |
8b5264aa | 166 | |
74ca738f | 167 | (void) kill(pager_pid, SIGCONT); |
c73d180d | 168 | (void) wait_for_terminate(pager_pid, NULL); |
1968a360 LP |
169 | pager_pid = 0; |
170 | } | |
f89a3b6f LP |
171 | |
172 | bool pager_have(void) { | |
173 | return pager_pid > 0; | |
174 | } | |
78002a67 ZJS |
175 | |
176 | int show_man_page(const char *desc, bool null_stdio) { | |
177 | const char *args[4] = { "man", NULL, NULL, NULL }; | |
178 | char *e = NULL; | |
179 | pid_t pid; | |
180 | size_t k; | |
181 | int r; | |
182 | siginfo_t status; | |
183 | ||
184 | k = strlen(desc); | |
185 | ||
186 | if (desc[k-1] == ')') | |
187 | e = strrchr(desc, '('); | |
188 | ||
189 | if (e) { | |
190 | char *page = NULL, *section = NULL; | |
191 | ||
192 | page = strndupa(desc, e - desc); | |
193 | section = strndupa(e + 1, desc + k - e - 2); | |
194 | ||
195 | args[1] = section; | |
196 | args[2] = page; | |
197 | } else | |
198 | args[1] = desc; | |
199 | ||
200 | pid = fork(); | |
4a62c710 MS |
201 | if (pid < 0) |
202 | return log_error_errno(errno, "Failed to fork: %m"); | |
78002a67 ZJS |
203 | |
204 | if (pid == 0) { | |
205 | /* Child */ | |
ce30c8dc LP |
206 | |
207 | (void) reset_all_signal_handlers(); | |
208 | (void) reset_signal_mask(); | |
209 | ||
78002a67 ZJS |
210 | if (null_stdio) { |
211 | r = make_null_stdio(); | |
212 | if (r < 0) { | |
da927ba9 | 213 | log_error_errno(r, "Failed to kill stdio: %m"); |
78002a67 ZJS |
214 | _exit(EXIT_FAILURE); |
215 | } | |
216 | } | |
217 | ||
218 | execvp(args[0], (char**) args); | |
56f64d95 | 219 | log_error_errno(errno, "Failed to execute man: %m"); |
78002a67 ZJS |
220 | _exit(EXIT_FAILURE); |
221 | } | |
222 | ||
223 | r = wait_for_terminate(pid, &status); | |
224 | if (r < 0) | |
225 | return r; | |
226 | ||
227 | log_debug("Exit code %i status %i", status.si_code, status.si_status); | |
228 | return status.si_status; | |
229 | } |