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 <systemd/sd-journal.h>
  34
  35 #include "log.h"
  36 #include "util.h"
  37 #include "build.h"
  38 #include "pager.h"
  39 #include "logs-show.h"
  40
  41 static OutputMode arg_output = OUTPUT_SHORT;
  42 static bool arg_follow = false;
  43 static bool arg_show_all = false;
  44 static bool arg_no_pager = false;
  45 static int arg_lines = -1;
  46 static bool arg_no_tail = false;
  47
  48 static int help(void) {
  49
  50         printf("%s [OPTIONS...] {COMMAND} ...\n\n"
  51                "Send control commands to or query the journal.\n\n"
  52                "  -h --help           Show this help\n"
  53                "     --version        Show package version\n"
  54                "     --no-pager       Do not pipe output into a pager\n"
  55                "  -a --all            Show all properties, including long and unprintable\n"
  56                "  -f --follow         Follow journal\n"
  57                "  -n --lines=INTEGER  Journal entries to show\n"
  58                "     --no-tail        Show all lines, even in follow mode\n"
  59                "  -o --output=STRING  Change journal output mode (short, verbose, export, json)\n",
  60                program_invocation_short_name);
  61
  62         return 0;
  63 }
  64
  65 static int parse_argv(int argc, char *argv[]) {
  66
  67         enum {
  68                 ARG_VERSION = 0x100,
  69                 ARG_NO_PAGER,
  70                 ARG_NO_TAIL
  71         };
  72
  73         static const struct option options[] = {
  74                 { "help",      no_argument,       NULL, 'h'           },
  75                 { "version" ,  no_argument,       NULL, ARG_VERSION   },
  76                 { "no-pager",  no_argument,       NULL, ARG_NO_PAGER  },
  77                 { "follow",    no_argument,       NULL, 'f'           },
  78                 { "output",    required_argument, NULL, 'o'           },
  79                 { "all",       no_argument,       NULL, 'a'           },
  80                 { "lines",     required_argument, NULL, 'n'           },
  81                 { "no-tail",   no_argument,       NULL, ARG_NO_TAIL   },
  82                 { NULL,        0,                 NULL, 0             }
  83         };
  84
  85         int c, r;
  86
  87         assert(argc >= 0);
  88         assert(argv);
  89
  90         while ((c = getopt_long(argc, argv, "hfo:an:", options, NULL)) >= 0) {
  91
  92                 switch (c) {
  93
  94                 case 'h':
  95                         help();
  96                         return 0;
  97
  98                 case ARG_VERSION:
  99                         puts(PACKAGE_STRING);
 100                         puts(DISTRIBUTION);
 101                         puts(SYSTEMD_FEATURES);
 102                         return 0;
 103
 104                 case ARG_NO_PAGER:
 105                         arg_no_pager = true;
 106                         break;
 107
 108                 case 'f':
 109                         arg_follow = true;
 110                         break;
 111
 112                 case 'o':
 113                         arg_output =  output_mode_from_string(optarg);
 114                         if (arg_output < 0) {
 115                                 log_error("Unknown output '%s'.", optarg);
 116                                 return -EINVAL;
 117                         }
 118
 119                         break;
 120
 121                 case 'a':
 122                         arg_show_all = true;
 123                         break;
 124
 125                 case 'n':
 126                         r = safe_atoi(optarg, &arg_lines);
 127                         if (r < 0 || arg_lines < 0) {
 128                                 log_error("Failed to parse lines '%s'", optarg);
 129                                 return -EINVAL;
 130                         }
 131                         break;
 132
 133                 case ARG_NO_TAIL:
 134                         arg_no_tail = true;
 135                         break;
 136
 137                 case '?':
 138                         return -EINVAL;
 139
 140                 default:
 141                         log_error("Unknown option code %c", c);
 142                         return -EINVAL;
 143                 }
 144         }
 145
 146         if (arg_follow && !arg_no_tail)
 147                 arg_lines = 10;
 148
 149         return 1;
 150 }
 151
 152 int main(int argc, char *argv[]) {
 153         int r, i, fd;
 154         sd_journal *j = NULL;
 155         unsigned line = 0;
 156         bool need_seek = false;
 157
 158         log_parse_environment();
 159         log_open();
 160
 161         r = parse_argv(argc, argv);
 162         if (r <= 0)
 163                 goto finish;
 164
 165         r = sd_journal_open(&j, 0);
 166         if (r < 0) {
 167                 log_error("Failed to open journal: %s", strerror(-r));
 168                 goto finish;
 169         }
 170
 171         for (i = optind; i < argc; i++) {
 172                 r = sd_journal_add_match(j, argv[i], strlen(argv[i]));
 173                 if (r < 0) {
 174                         log_error("Failed to add match: %s", strerror(-r));
 175                         goto finish;
 176                 }
 177         }
 178
 179         fd = sd_journal_get_fd(j);
 180         if (fd < 0) {
 181                 log_error("Failed to get wakeup fd: %s", strerror(-fd));
 182                 goto finish;
 183         }
 184
 185         if (arg_lines >= 0) {
 186                 r = sd_journal_seek_tail(j);
 187                 if (r < 0) {
 188                         log_error("Failed to seek to tail: %s", strerror(-r));
 189                         goto finish;
 190                 }
 191
 192                 r = sd_journal_previous_skip(j, arg_lines);
 193         } else {
 194                 r = sd_journal_seek_head(j);
 195                 if (r < 0) {
 196                         log_error("Failed to seek to head: %s", strerror(-r));
 197                         goto finish;
 198                 }
 199
 200                 r = sd_journal_next(j);
 201         }
 202
 203         if (r < 0) {
 204                 log_error("Failed to iterate through journal: %s", strerror(-r));
 205                 goto finish;
 206         }
 207
 208         if (!arg_no_pager && !arg_follow) {
 209                 columns();
 210                 pager_open();
 211         }
 212
 213         if (arg_output == OUTPUT_JSON) {
 214                 fputc('[', stdout);
 215                 fflush(stdout);
 216         }
 217
 218         for (;;) {
 219                 for (;;) {
 220                         if (need_seek) {
 221                                 r = sd_journal_next(j);
 222                                 if (r < 0) {
 223                                         log_error("Failed to iterate through journal: %s", strerror(-r));
 224                                         goto finish;
 225                                 }
 226                         }
 227
 228                         if (r == 0)
 229                                 break;
 230
 231                         line ++;
 232
 233                         r = output_journal(j, arg_output, line, arg_show_all);
 234                         if (r < 0)
 235                                 goto finish;
 236
 237                         need_seek = true;
 238                 }
 239
 240                 if (!arg_follow)
 241                         break;
 242
 243                 r = fd_wait_for_event(fd, POLLIN);
 244                 if (r < 0) {
 245                         log_error("Couldn't wait for event: %s", strerror(-r));
 246                         goto finish;
 247                 }
 248
 249                 r = sd_journal_process(j);
 250                 if (r < 0) {
 251                         log_error("Failed to process: %s", strerror(-r));
 252                         goto finish;
 253                 }
 254         }
 255
 256         if (arg_output == OUTPUT_JSON)
 257                 fputs("\n]\n", stdout);
 258
 259 finish:
 260         if (j)
 261                 sd_journal_close(j);
 262
 263         pager_close();
 264
 265         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 266 }