src/shared/sysctl-util.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2010 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <stdio.h>
  21 #include <string.h>
  22
  23 #include "fileio.h"
  24 #include "log.h"
  25 #include "macro.h"
  26 #include "string-util.h"
  27 #include "sysctl-util.h"
  28
  29 char *sysctl_normalize(char *s) {
  30         char *n;
  31
  32         n = strpbrk(s, "/.");
  33         /* If the first separator is a slash, the path is
  34          * assumed to be normalized and slashes remain slashes
  35          * and dots remains dots. */
  36         if (!n || *n == '/')
  37                 return s;
  38
  39         /* Otherwise, dots become slashes and slashes become
  40          * dots. Fun. */
  41         while (n) {
  42                 if (*n == '.')
  43                         *n = '/';
  44                 else
  45                         *n = '.';
  46
  47                 n = strpbrk(n + 1, "/.");
  48         }
  49
  50         return s;
  51 }
  52
  53 int sysctl_write(const char *property, const char *value) {
  54         char *p;
  55
  56         assert(property);
  57         assert(value);
  58
  59         log_debug("Setting '%s' to '%s'", property, value);
  60
  61         p = strjoina("/proc/sys/", property);
  62         return write_string_file(p, value, 0);
  63 }
  64
  65 int sysctl_read(const char *property, char **content) {
  66         char *p;
  67
  68         assert(property);
  69         assert(content);
  70
  71         p = strjoina("/proc/sys/", property);
  72         return read_full_file(p, content, NULL);
  73 }