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 OutputMode 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 journal.\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  Journal entries to show\n"
  57                "     --no-tail        Show all lines, even in follow mode\n"
  58                "  -o --output=STRING  Change journal 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                         arg_output =  output_mode_from_string(optarg);
 113                         if (arg_output < 0) {
 114                                 log_error("Unknown output '%s'.", optarg);
 115                                 return -EINVAL;
 116                         }
 117
 118                         break;
 119
 120                 case 'a':
 121                         arg_show_all = true;
 122                         break;
 123
 124                 case 'n':
 125                         r = safe_atoi(optarg, &arg_lines);
 126                         if (r < 0 || arg_lines < 0) {
 127                                 log_error("Failed to parse lines '%s'", optarg);
 128                                 return -EINVAL;
 129                         }
 130                         break;
 131
 132                 case ARG_NO_TAIL:
 133                         arg_no_tail = true;
 134                         break;
 135
 136                 case '?':
 137                         return -EINVAL;
 138
 139                 default:
 140                         log_error("Unknown option code %c", c);
 141                         return -EINVAL;
 142                 }
 143         }
 144
 145         if (arg_follow && !arg_no_tail)
 146                 arg_lines = 10;
 147
 148         return 1;
 149 }
 150
 151 int main(int argc, char *argv[]) {
 152         int r, i, fd;
 153         sd_journal *j = NULL;
 154         unsigned line = 0;
 155         bool need_seek = false;
 156
 157         log_parse_environment();
 158         log_open();
 159
 160         r = parse_argv(argc, argv);
 161         if (r <= 0)
 162                 goto finish;
 163
 164         r = sd_journal_open(&j, 0);
 165         if (r < 0) {
 166                 log_error("Failed to open journal: %s", strerror(-r));
 167                 goto finish;
 168         }
 169
 170         for (i = optind; i < argc; i++) {
 171                 r = sd_journal_add_match(j, argv[i], strlen(argv[i]));
 172                 if (r < 0) {
 173                         log_error("Failed to add match: %s", strerror(-r));
 174                         goto finish;
 175                 }
 176         }
 177
 178         fd = sd_journal_get_fd(j);
 179         if (fd < 0) {
 180                 log_error("Failed to get wakeup fd: %s", strerror(-fd));
 181                 goto finish;
 182         }
 183
 184         if (arg_lines >= 0) {
 185                 r = sd_journal_seek_tail(j);
 186                 if (r < 0) {
 187                         log_error("Failed to seek to tail: %s", strerror(-r));
 188                         goto finish;
 189                 }
 190
 191                 r = sd_journal_previous_skip(j, arg_lines);
 192         } else {
 193                 r = sd_journal_seek_head(j);
 194                 if (r < 0) {
 195                         log_error("Failed to seek to head: %s", strerror(-r));
 196                         goto finish;
 197                 }
 198
 199                 r = sd_journal_next(j);
 200         }
 201
 202         if (r < 0) {
 203                 log_error("Failed to iterate through journal: %s", strerror(-r));
 204                 goto finish;
 205         }
 206
 207         if (!arg_no_pager && !arg_follow) {
 208                 columns();
 209                 pager_open();
 210         }
 211
 212         if (arg_output == OUTPUT_JSON) {
 213                 fputc('[', stdout);
 214                 fflush(stdout);
 215         }
 216
 217         for (;;) {
 218                 for (;;) {
 219                         if (need_seek) {
 220                                 r = sd_journal_next(j);
 221                                 if (r < 0) {
 222                                         log_error("Failed to iterate through journal: %s", strerror(-r));
 223                                         goto finish;
 224                                 }
 225                         }
 226
 227                         if (r == 0)
 228                                 break;
 229
 230                         line ++;
 231
 232                         r = output_journal(j, arg_output, line, arg_show_all);
 233                         if (r < 0)
 234                                 goto finish;
 235
 236                         need_seek = true;
 237                 }
 238
 239                 if (!arg_follow)
 240                         break;
 241
 242                 r = fd_wait_for_event(fd, POLLIN);
 243                 if (r < 0) {
 244                         log_error("Couldn't wait for event: %s", strerror(-r));
 245                         goto finish;
 246                 }
 247
 248                 r = sd_journal_process(j);
 249                 if (r < 0) {
 250                         log_error("Failed to process: %s", strerror(-r));
 251                         goto finish;
 252                 }
 253         }
 254
 255         if (arg_output == OUTPUT_JSON)
 256                 fputs("\n]\n", stdout);
 257
 258 finish:
 259         if (j)
 260                 sd_journal_close(j);
 261
 262         pager_close();
 263
 264         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 265 }