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 static bool arg_kernel_threads = false;
  37
  38 static void help(void) {
  39
  40         printf("%s [OPTIONS...] [CGROUP...]\n\n"
  41                "Recursively show control group contents.\n\n"
  42                "  -h --help           Show this help\n"
  43                "     --no-pager       Do not pipe output into a pager\n"
  44                "  -k                  Include kernel threads in output\n",
  45                program_invocation_short_name);
  46 }
  47
  48 static int parse_argv(int argc, char *argv[]) {
  49
  50         enum {
  51                 ARG_NO_PAGER = 0x100
  52         };
  53
  54         static const struct option options[] = {
  55                 { "help",      no_argument,       NULL, 'h'          },
  56                 { "no-pager",  no_argument,       NULL, ARG_NO_PAGER },
  57                 { NULL,        0,                 NULL, 0            }
  58         };
  59
  60         int c;
  61
  62         assert(argc >= 1);
  63         assert(argv);
  64
  65         while ((c = getopt_long(argc, argv, "hk", options, NULL)) >= 0) {
  66
  67                 switch (c) {
  68
  69                 case 'h':
  70                         help();
  71                         return 0;
  72
  73                 case ARG_NO_PAGER:
  74                         arg_no_pager = true;
  75                         break;
  76
  77                 case 'k':
  78                         arg_kernel_threads = true;
  79                         break;
  80
  81                 case '?':
  82                         return -EINVAL;
  83
  84                 default:
  85                         log_error("Unknown option code %c", c);
  86                         return -EINVAL;
  87                 }
  88         }
  89
  90         return 1;
  91 }
  92
  93 int main(int argc, char *argv[]) {
  94         int r = 0, retval = EXIT_FAILURE;
  95
  96         log_parse_environment();
  97         log_open();
  98
  99         r = parse_argv(argc, argv);
 100         if (r < 0)
 101                 goto finish;
 102         else if (r == 0) {
 103                 retval = EXIT_SUCCESS;
 104                 goto finish;
 105         }
 106
 107         if (!arg_no_pager)
 108                 pager_open();
 109
 110         if (optind < argc) {
 111                 unsigned i;
 112
 113                 for (i = (unsigned) optind; i < (unsigned) argc; i++) {
 114                         int q;
 115                         printf("%s:\n", argv[i]);
 116
 117                         q = show_cgroup_by_path(argv[i], NULL, 0, arg_kernel_threads);
 118                         if (q < 0)
 119                                 r = q;
 120                 }
 121
 122         } else {
 123                 char *p;
 124
 125                 p = get_current_dir_name();
 126                 if (!p) {
 127                         log_error("Cannot determine current working directory: %m");
 128                         goto finish;
 129                 }
 130
 131                 if (path_startswith(p, "/sys/fs/cgroup")) {
 132                         printf("Working Directory %s:\n", p);
 133                         r = show_cgroup_by_path(p, NULL, 0, arg_kernel_threads);
 134                 } else {
 135                         char *root = NULL;
 136                         const char *t = NULL;
 137
 138                         r = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 1, &root);
 139                         if (r < 0)
 140                                 t = "/";
 141                         else {
 142                                 if (endswith(root, "/system"))
 143                                         root[strlen(root)-7] = 0;
 144
 145                                 t = root[0] ? root : "/";
 146                         }
 147
 148                         r = show_cgroup(SYSTEMD_CGROUP_CONTROLLER, t, NULL, 0, arg_kernel_threads);
 149                         free(root);
 150                 }
 151
 152                 free(p);
 153         }
 154
 155         if (r < 0)
 156                 log_error("Failed to list cgroup tree: %s", strerror(-r));
 157
 158         retval = EXIT_SUCCESS;
 159
 160 finish:
 161         pager_close();
 162
 163         return retval;
 164 }