src/cgls.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 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 <limits.h>
  23 #include <stdio.h>
  24 #include <unistd.h>
  25 #include <errno.h>
  26 #include <getopt.h>
  27 #include <string.h>
  28
  29 #include "cgroup-show.h"
  30 #include "cgroup-util.h"
  31 #include "log.h"
  32 #include "util.h"
  33 #include "pager.h"
  34
  35 static bool arg_no_pager = false;
  36
  37 static void help(void) {
  38
  39         printf("%s [OPTIONS...] [CGROUP...]\n\n"
  40                "Recursively show control group contents.\n\n"
  41                "  -h --help           Show this help\n"
  42                "     --no-pager       Do not pipe output into a pager\n",
  43                program_invocation_short_name);
  44 }
  45
  46 static int parse_argv(int argc, char *argv[]) {
  47
  48         enum {
  49                 ARG_NO_PAGER = 0x100
  50         };
  51
  52         static const struct option options[] = {
  53                 { "help",      no_argument,       NULL, 'h'          },
  54                 { "no-pager",  no_argument,       NULL, ARG_NO_PAGER },
  55                 { NULL,        0,                 NULL, 0            }
  56         };
  57
  58         int c;
  59
  60         assert(argc >= 1);
  61         assert(argv);
  62
  63         while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) {
  64
  65                 switch (c) {
  66
  67                 case 'h':
  68                         help();
  69                         return 0;
  70
  71                 case ARG_NO_PAGER:
  72                         arg_no_pager = true;
  73                         break;
  74
  75                 case '?':
  76                         return -EINVAL;
  77
  78                 default:
  79                         log_error("Unknown option code %c", c);
  80                         return -EINVAL;
  81                 }
  82         }
  83
  84         return 1;
  85 }
  86
  87 int main(int argc, char *argv[]) {
  88         int r = 0, retval = EXIT_FAILURE;
  89
  90         log_parse_environment();
  91         log_open();
  92
  93         if ((r = parse_argv(argc, argv)) < 0)
  94                 goto finish;
  95         else if (r == 0) {
  96                 retval = EXIT_SUCCESS;
  97                 goto finish;
  98         }
  99
 100         if (!arg_no_pager)
 101                 pager_open();
 102
 103         if (optind < argc) {
 104                 unsigned i;
 105
 106                 for (i = (unsigned) optind; i < (unsigned) argc; i++) {
 107                         int q;
 108                         printf("%s:\n", argv[i]);
 109
 110                         if ((q = show_cgroup_by_path(argv[i], NULL, 0)) < 0)
 111                                 r = q;
 112                 }
 113
 114         } else {
 115                 char *p;
 116
 117                 if (!(p = get_current_dir_name())) {
 118                         log_error("Cannot determine current working directory: %m");
 119                         goto finish;
 120                 }
 121
 122                 if (path_startswith(p, "/sys/fs/cgroup")) {
 123                         printf("Working Directory %s:\n", p);
 124                         r = show_cgroup_by_path(p, NULL, 0);
 125                 } else {
 126                         char *root = NULL;
 127                         const char *t = NULL;
 128
 129                         if ((r = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 1, &root)) < 0)
 130                                 t = "/";
 131                         else {
 132                                 if (endswith(root, "/system"))
 133                                         root[strlen(root)-7] = 0;
 134
 135                                 t = root[0] ? root : "/";
 136                         }
 137
 138                         r = show_cgroup(SYSTEMD_CGROUP_CONTROLLER, t, NULL, 0);
 139                         free(root);
 140                 }
 141
 142                 free(p);
 143         }
 144
 145         if (r < 0)
 146                 log_error("Failed to list cgroup tree: %s", strerror(-r));
 147
 148         retval = EXIT_SUCCESS;
 149
 150 finish:
 151         pager_close();
 152
 153         return retval;
 154 }