src/journal/journalctl.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2011 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 of the License, or
  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
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <fcntl.h>
  23 #include <errno.h>
  24 #include <stddef.h>
  25 #include <string.h>
  26 #include <stdio.h>
  27 #include <unistd.h>
  28 #include <stdlib.h>
  29 #include <sys/poll.h>
  30 #include <time.h>
  31 #include <getopt.h>
  32
  33 #include "sd-journal.h"
  34 #include "log.h"
  35 #include "util.h"
  36 #include "build.h"
  37 #include "pager.h"
  38 #include "logs-show.h"
  39
  40 static output_mode arg_output = OUTPUT_SHORT;
  41 static bool arg_follow = false;
  42 static bool arg_show_all = false;
  43 static bool arg_no_pager = false;
  44 static int arg_lines = -1;
  45 static bool arg_no_tail = false;
  46
  47 static int help(void) {
  48
  49         printf("%s [OPTIONS...] {COMMAND} ...\n\n"
  50                "Send control commands to or query the login manager.\n\n"
  51                "  -h --help           Show this help\n"
  52                "     --version        Show package version\n"
  53                "     --no-pager       Do not pipe output into a pager\n"
  54                "  -a --all            Show all properties, including long and unprintable\n"
  55                "  -f --follow         Follow journal\n"
  56                "  -n --lines=INTEGER  Lines to show\n"
  57                "     --no-tail        Show all lines, even in follow mode\n"
  58                "  -o --output=STRING  Change output mode (short, verbose, export, json)\n",
  59                program_invocation_short_name);
  60
  61         return 0;
  62 }
  63
  64 static int parse_argv(int argc, char *argv[]) {
  65
  66         enum {
  67                 ARG_VERSION = 0x100,
  68                 ARG_NO_PAGER,
  69                 ARG_NO_TAIL
  70         };
  71
  72         static const struct option options[] = {
  73                 { "help",      no_argument,       NULL, 'h'           },
  74                 { "version" ,  no_argument,       NULL, ARG_VERSION   },
  75                 { "no-pager",  no_argument,       NULL, ARG_NO_PAGER  },
  76                 { "follow",    no_argument,       NULL, 'f'           },
  77                 { "output",    required_argument, NULL, 'o'           },
  78                 { "all",       no_argument,       NULL, 'a'           },
  79                 { "lines",     required_argument, NULL, 'n'           },
  80                 { "no-tail",   no_argument,       NULL, ARG_NO_TAIL   },
  81                 { NULL,        0,                 NULL, 0             }
  82         };
  83
  84         int c, r;
  85
  86         assert(argc >= 0);
  87         assert(argv);
  88
  89         while ((c = getopt_long(argc, argv, "hfo:an:", options, NULL)) >= 0) {
  90
  91                 switch (c) {
  92
  93                 case 'h':
  94                         help();
  95                         return 0;
  96
  97                 case ARG_VERSION:
  98                         puts(PACKAGE_STRING);
  99                         puts(DISTRIBUTION);
 100                         puts(SYSTEMD_FEATURES);
 101                         return 0;
 102
 103                 case ARG_NO_PAGER:
 104                         arg_no_pager = true;
 105                         break;
 106
 107                 case 'f':
 108                         arg_follow = true;
 109                         break;
 110
 111                 case 'o':
 112                         if (streq(optarg, "short"))
 113                                 arg_output = OUTPUT_SHORT;
 114                         else if (streq(optarg, "verbose"))
 115                                 arg_output = OUTPUT_VERBOSE;
 116                         else if (streq(optarg, "export"))
 117                                 arg_output = OUTPUT_EXPORT;
 118                         else if (streq(optarg, "json"))
 119                                 arg_output = OUTPUT_JSON;
 120                         else {
 121                                 log_error("Unknown output '%s'.", optarg);
 122                                 return -EINVAL;
 123                         }
 124                         break;
 125
 126                 case 'a':
 127                         arg_show_all = true;
 128                         break;
 129
 130                 case 'n':
 131                         r = safe_atoi(optarg, &arg_lines);
 132                         if (r < 0 || arg_lines < 0) {
 133                                 log_error("Failed to parse lines '%s'", optarg);
 134                                 return -EINVAL;
 135                         }
 136                         break;
 137
 138                 case ARG_NO_TAIL:
 139                         arg_no_tail = true;
 140                         break;
 141
 142                 case '?':
 143                         return -EINVAL;
 144
 145                 default:
 146                         log_error("Unknown option code %c", c);
 147                         return -EINVAL;
 148                 }
 149         }
 150
 151         if (arg_follow && !arg_no_tail)
 152                 arg_lines = 10;
 153
 154         return 1;
 155 }
 156
 157 int main(int argc, char *argv[]) {
 158         int r, i, fd;
 159         sd_journal *j = NULL;
 160         unsigned line = 0;
 161         bool need_seek = false;
 162
 163         log_parse_environment();
 164         log_open();
 165
 166         r = parse_argv(argc, argv);
 167         if (r <= 0)
 168                 goto finish;
 169
 170         r = sd_journal_open(&j, 0);
 171         if (r < 0) {
 172                 log_error("Failed to open journal: %s", strerror(-r));
 173                 goto finish;
 174         }
 175
 176         for (i = optind; i < argc; i++) {
 177                 r = sd_journal_add_match(j, argv[i], strlen(argv[i]));
 178                 if (r < 0) {
 179                         log_error("Failed to add match: %s", strerror(-r));
 180                         goto finish;
 181                 }
 182         }
 183
 184         fd = sd_journal_get_fd(j);
 185         if (fd < 0) {
 186                 log_error("Failed to get wakeup fd: %s", strerror(-fd));
 187                 goto finish;
 188         }
 189
 190         if (arg_lines >= 0) {
 191                 r = sd_journal_seek_tail(j);
 192                 if (r < 0) {
 193                         log_error("Failed to seek to tail: %s", strerror(-r));
 194                         goto finish;
 195                 }
 196
 197                 r = sd_journal_previous_skip(j, arg_lines);
 198         } else {
 199                 r = sd_journal_seek_head(j);
 200                 if (r < 0) {
 201                         log_error("Failed to seek to head: %s", strerror(-r));
 202                         goto finish;
 203                 }
 204
 205                 r = sd_journal_next(j);
 206         }
 207
 208         if (r < 0) {
 209                 log_error("Failed to iterate through journal: %s", strerror(-r));
 210                 goto finish;
 211         }
 212
 213         if (!arg_no_pager && !arg_follow) {
 214                 columns();
 215                 pager_open();
 216         }
 217
 218         if (arg_output == OUTPUT_JSON) {
 219                 fputc('[', stdout);
 220                 fflush(stdout);
 221         }
 222
 223         for (;;) {
 224                 struct pollfd pollfd;
 225
 226                 for (;;) {
 227                         if (need_seek) {
 228                                 r = sd_journal_next(j);
 229                                 if (r < 0) {
 230                                         log_error("Failed to iterate through journal: %s", strerror(-r));
 231                                         goto finish;
 232                                 }
 233                         }
 234
 235                         if (r == 0)
 236                                 break;
 237
 238                         line ++;
 239
 240                         r = output_journal(j, arg_output, line, arg_show_all);
 241                         if (r < 0)
 242                                 goto finish;
 243
 244                         need_seek = true;
 245                 }
 246
 247                 if (!arg_follow)
 248                         break;
 249
 250                 zero(pollfd);
 251                 pollfd.fd = fd;
 252                 pollfd.events = POLLIN;
 253
 254                 if (poll(&pollfd, 1, -1) < 0) {
 255                         if (errno == EINTR)
 256                                 break;
 257
 258                         log_error("poll(): %m");
 259                         r = -errno;
 260                         goto finish;
 261                 }
 262
 263                 r = sd_journal_process(j);
 264                 if (r < 0) {
 265                         log_error("Failed to process: %s", strerror(-r));
 266                         goto finish;
 267                 }
 268         }
 269
 270         if (arg_output == OUTPUT_JSON)
 271                 fputs("\n]\n", stdout);
 272
 273 finish:
 274         if (j)
 275                 sd_journal_close(j);
 276
 277         pager_close();
 278
 279         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 280 }