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 properties, 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
 152                 case '?':
 153                         return -EINVAL;
 154
 155                 default:
 156                         log_error("Unknown option code %c", c);
 157                         return -EINVAL;
 158                 }
 159         }
 160
 161         if (arg_follow && !arg_no_tail && arg_lines < 0)
 162                 arg_lines = 10;
 163
 164         return 1;
 165 }
 166
 167 static int generate_new_id128(void) {
 168         sd_id128_t id;
 169         int r;
 170         unsigned i;
 171
 172         r = sd_id128_randomize(&id);
 173         if (r < 0) {
 174                 log_error("Failed to generate ID: %s", strerror(-r));
 175                 return r;
 176         }
 177
 178         printf("As string:\n"
 179                SD_ID128_FORMAT_STR "\n\n"
 180                "As UUID:\n"
 181                "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x\n\n"
 182                "As macro:\n"
 183               "#define MESSAGE_XYZ SD_ID128_MAKE(",
 184                SD_ID128_FORMAT_VAL(id),
 185                SD_ID128_FORMAT_VAL(id));
 186
 187         for (i = 0; i < 16; i++)
 188                 printf("%02x%s", id.bytes[i], i != 15 ? "," : "");
 189
 190         fputs(")\n", stdout);
 191
 192         return 0;
 193 }
 194
 195 int main(int argc, char *argv[]) {
 196         int r, i, fd;
 197         sd_journal *j = NULL;
 198         unsigned line = 0;
 199         bool need_seek = false;
 200
 201         log_parse_environment();
 202         log_open();
 203
 204         r = parse_argv(argc, argv);
 205         if (r <= 0)
 206                 goto finish;
 207
 208         if (arg_new_id128) {
 209                 r = generate_new_id128();
 210                 goto finish;
 211         }
 212
 213 #ifdef HAVE_ACL
 214         if (!arg_quiet && geteuid() != 0 && in_group("adm") <= 0)
 215                 log_warning("Showing user generated messages only. Users in the group 'adm' can see all messages. Pass -q to turn this message off.");
 216 #endif
 217
 218         r = sd_journal_open(&j, 0);
 219         if (r < 0) {
 220                 log_error("Failed to open journal: %s", strerror(-r));
 221                 goto finish;
 222         }
 223
 224         for (i = optind; i < argc; i++) {
 225                 r = sd_journal_add_match(j, argv[i], strlen(argv[i]));
 226                 if (r < 0) {
 227                         log_error("Failed to add match: %s", strerror(-r));
 228                         goto finish;
 229                 }
 230         }
 231
 232         fd = sd_journal_get_fd(j);
 233         if (fd < 0) {
 234                 log_error("Failed to get wakeup fd: %s", strerror(-fd));
 235                 goto finish;
 236         }
 237
 238         if (arg_lines >= 0) {
 239                 r = sd_journal_seek_tail(j);
 240                 if (r < 0) {
 241                         log_error("Failed to seek to tail: %s", strerror(-r));
 242                         goto finish;
 243                 }
 244
 245                 r = sd_journal_previous_skip(j, arg_lines);
 246         } else {
 247                 r = sd_journal_seek_head(j);
 248                 if (r < 0) {
 249                         log_error("Failed to seek to head: %s", strerror(-r));
 250                         goto finish;
 251                 }
 252
 253                 r = sd_journal_next(j);
 254         }
 255
 256         if (r < 0) {
 257                 log_error("Failed to iterate through journal: %s", strerror(-r));
 258                 goto finish;
 259         }
 260
 261         if (!arg_no_pager && !arg_follow) {
 262                 columns();
 263                 pager_open();
 264         }
 265
 266         if (arg_output == OUTPUT_JSON) {
 267                 fputc('[', stdout);
 268                 fflush(stdout);
 269         }
 270
 271         for (;;) {
 272                 for (;;) {
 273                         if (need_seek) {
 274                                 r = sd_journal_next(j);
 275                                 if (r < 0) {
 276                                         log_error("Failed to iterate through journal: %s", strerror(-r));
 277                                         goto finish;
 278                                 }
 279                         }
 280
 281                         if (r == 0)
 282                                 break;
 283
 284                         line ++;
 285
 286                         r = output_journal(j, arg_output, line, arg_show_all);
 287                         if (r < 0)
 288                                 goto finish;
 289
 290                         need_seek = true;
 291                 }
 292
 293                 if (!arg_follow)
 294                         break;
 295
 296                 r = fd_wait_for_event(fd, POLLIN, (usec_t) -1);
 297                 if (r < 0) {
 298                         log_error("Couldn't wait for event: %s", strerror(-r));
 299                         goto finish;
 300                 }
 301
 302                 r = sd_journal_process(j);
 303                 if (r < 0) {
 304                         log_error("Failed to process: %s", strerror(-r));
 305                         goto finish;
 306                 }
 307         }
 308
 309         if (arg_output == OUTPUT_JSON)
 310                 fputs("\n]\n", stdout);
 311
 312 finish:
 313         if (j)
 314                 sd_journal_close(j);
 315
 316         pager_close();
 317
 318         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 319 }