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 static bool arg_new_id128 = false;
  48 static bool arg_quiet = false;
  49
  50 static int help(void) {
  51
  52         printf("%s [OPTIONS...] {COMMAND} ...\n\n"
  53                "Send control commands to or query the journal.\n\n"
  54                "  -h --help           Show this help\n"
  55                "     --version        Show package version\n"
  56                "     --no-pager       Do not pipe output into a pager\n"
  57                "  -a --all            Show all fields, including long and unprintable\n"
  58                "  -f --follow         Follow journal\n"
  59                "  -n --lines=INTEGER  Journal entries to show\n"
  60                "     --no-tail        Show all lines, even in follow mode\n"
  61                "  -o --output=STRING  Change journal output mode (short, short-monotonic,\n"
  62                "                      verbose, export, json, cat)\n"
  63                "  -q --quiet          Don't show privilege warning\n"
  64                "     --new-id128      Generate a new 128 Bit id\n",
  65                program_invocation_short_name);
  66
  67         return 0;
  68 }
  69
  70 static int parse_argv(int argc, char *argv[]) {
  71
  72         enum {
  73                 ARG_VERSION = 0x100,
  74                 ARG_NO_PAGER,
  75                 ARG_NO_TAIL,
  76                 ARG_NEW_ID128
  77         };
  78
  79         static const struct option options[] = {
  80                 { "help",      no_argument,       NULL, 'h'           },
  81                 { "version" ,  no_argument,       NULL, ARG_VERSION   },
  82                 { "no-pager",  no_argument,       NULL, ARG_NO_PAGER  },
  83                 { "follow",    no_argument,       NULL, 'f'           },
  84                 { "output",    required_argument, NULL, 'o'           },
  85                 { "all",       no_argument,       NULL, 'a'           },
  86                 { "lines",     required_argument, NULL, 'n'           },
  87                 { "no-tail",   no_argument,       NULL, ARG_NO_TAIL   },
  88                 { "new-id128", no_argument,       NULL, ARG_NEW_ID128 },
  89                 { "quiet",     no_argument,       NULL, 'q'           },
  90                 { NULL,        0,                 NULL, 0             }
  91         };
  92
  93         int c, r;
  94
  95         assert(argc >= 0);
  96         assert(argv);
  97
  98         while ((c = getopt_long(argc, argv, "hfo:an:q", options, NULL)) >= 0) {
  99
 100                 switch (c) {
 101
 102                 case 'h':
 103                         help();
 104                         return 0;
 105
 106                 case ARG_VERSION:
 107                         puts(PACKAGE_STRING);
 108                         puts(DISTRIBUTION);
 109                         puts(SYSTEMD_FEATURES);
 110                         return 0;
 111
 112                 case ARG_NO_PAGER:
 113                         arg_no_pager = true;
 114                         break;
 115
 116                 case 'f':
 117                         arg_follow = true;
 118                         break;
 119
 120                 case 'o':
 121                         arg_output =  output_mode_from_string(optarg);
 122                         if (arg_output < 0) {
 123                                 log_error("Unknown output '%s'.", optarg);
 124                                 return -EINVAL;
 125                         }
 126
 127                         break;
 128
 129                 case 'a':
 130                         arg_show_all = true;
 131                         break;
 132
 133                 case 'n':
 134                         r = safe_atoi(optarg, &arg_lines);
 135                         if (r < 0 || arg_lines < 0) {
 136                                 log_error("Failed to parse lines '%s'", optarg);
 137                                 return -EINVAL;
 138                         }
 139                         break;
 140
 141                 case ARG_NO_TAIL:
 142                         arg_no_tail = true;
 143                         break;
 144
 145                 case ARG_NEW_ID128:
 146                         arg_new_id128 = true;
 147                         break;
 148
 149                 case 'q':
 150                         arg_quiet = true;
 151                         break;
 152
 153                 case '?':
 154                         return -EINVAL;
 155
 156                 default:
 157                         log_error("Unknown option code %c", c);
 158                         return -EINVAL;
 159                 }
 160         }
 161
 162         if (arg_follow && !arg_no_tail && arg_lines < 0)
 163                 arg_lines = 10;
 164
 165         return 1;
 166 }
 167
 168 static int generate_new_id128(void) {
 169         sd_id128_t id;
 170         int r;
 171         unsigned i;
 172
 173         r = sd_id128_randomize(&id);
 174         if (r < 0) {
 175                 log_error("Failed to generate ID: %s", strerror(-r));
 176                 return r;
 177         }
 178
 179         printf("As string:\n"
 180                SD_ID128_FORMAT_STR "\n\n"
 181                "As UUID:\n"
 182                "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x\n\n"
 183                "As macro:\n"
 184               "#define MESSAGE_XYZ SD_ID128_MAKE(",
 185                SD_ID128_FORMAT_VAL(id),
 186                SD_ID128_FORMAT_VAL(id));
 187
 188         for (i = 0; i < 16; i++)
 189                 printf("%02x%s", id.bytes[i], i != 15 ? "," : "");
 190
 191         fputs(")\n", stdout);
 192
 193         return 0;
 194 }
 195
 196 int main(int argc, char *argv[]) {
 197         int r, i, fd;
 198         sd_journal *j = NULL;
 199         unsigned line = 0;
 200         bool need_seek = false;
 201
 202         log_parse_environment();
 203         log_open();
 204
 205         r = parse_argv(argc, argv);
 206         if (r <= 0)
 207                 goto finish;
 208
 209         if (arg_new_id128) {
 210                 r = generate_new_id128();
 211                 goto finish;
 212         }
 213
 214 #ifdef HAVE_ACL
 215         if (!arg_quiet && geteuid() != 0 && in_group("adm") <= 0)
 216                 log_warning("Showing user generated messages only. Users in the group 'adm' can see all messages. Pass -q to turn this message off.");
 217 #endif
 218
 219         r = sd_journal_open(&j, 0);
 220         if (r < 0) {
 221                 log_error("Failed to open journal: %s", strerror(-r));
 222                 goto finish;
 223         }
 224
 225         for (i = optind; i < argc; i++) {
 226                 r = sd_journal_add_match(j, argv[i], strlen(argv[i]));
 227                 if (r < 0) {
 228                         log_error("Failed to add match: %s", strerror(-r));
 229                         goto finish;
 230                 }
 231         }
 232
 233         fd = sd_journal_get_fd(j);
 234         if (fd < 0) {
 235                 log_error("Failed to get wakeup fd: %s", strerror(-fd));
 236                 goto finish;
 237         }
 238
 239         if (arg_lines >= 0) {
 240                 r = sd_journal_seek_tail(j);
 241                 if (r < 0) {
 242                         log_error("Failed to seek to tail: %s", strerror(-r));
 243                         goto finish;
 244                 }
 245
 246                 r = sd_journal_previous_skip(j, arg_lines);
 247         } else {
 248                 r = sd_journal_seek_head(j);
 249                 if (r < 0) {
 250                         log_error("Failed to seek to head: %s", strerror(-r));
 251                         goto finish;
 252                 }
 253
 254                 r = sd_journal_next(j);
 255         }
 256
 257         if (r < 0) {
 258                 log_error("Failed to iterate through journal: %s", strerror(-r));
 259                 goto finish;
 260         }
 261
 262         if (!arg_no_pager && !arg_follow) {
 263                 columns();
 264                 pager_open();
 265         }
 266
 267         if (arg_output == OUTPUT_JSON) {
 268                 fputc('[', stdout);
 269                 fflush(stdout);
 270         }
 271
 272         for (;;) {
 273                 for (;;) {
 274                         if (need_seek) {
 275                                 r = sd_journal_next(j);
 276                                 if (r < 0) {
 277                                         log_error("Failed to iterate through journal: %s", strerror(-r));
 278                                         goto finish;
 279                                 }
 280                         }
 281
 282                         if (r == 0)
 283                                 break;
 284
 285                         line ++;
 286
 287                         r = output_journal(j, arg_output, line, 0, arg_show_all);
 288                         if (r < 0)
 289                                 goto finish;
 290
 291                         need_seek = true;
 292                 }
 293
 294                 if (!arg_follow)
 295                         break;
 296
 297                 r = fd_wait_for_event(fd, POLLIN, (usec_t) -1);
 298                 if (r < 0) {
 299                         log_error("Couldn't wait for event: %s", strerror(-r));
 300                         goto finish;
 301                 }
 302
 303                 r = sd_journal_process(j);
 304                 if (r < 0) {
 305                         log_error("Failed to process: %s", strerror(-r));
 306                         goto finish;
 307                 }
 308         }
 309
 310         if (arg_output == OUTPUT_JSON)
 311                 fputs("\n]\n", stdout);
 312
 313 finish:
 314         if (j)
 315                 sd_journal_close(j);
 316
 317         pager_close();
 318
 319         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 320 }