src/shared/specifier.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 Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 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   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <string.h>
  23
  24 #include "macro.h"
  25 #include "util.h"
  26 #include "specifier.h"
  27
  28 /*
  29  * Generic infrastructure for replacing %x style specifiers in
  30  * strings. Will call a callback for each replacement.
  31  *
  32  */
  33
  34 char *specifier_printf(const char *text, const Specifier table[], void *userdata) {
  35         char *r, *t;
  36         const char *f;
  37         bool percent = false;
  38         size_t l;
  39
  40         assert(text);
  41         assert(table);
  42
  43         l = strlen(text);
  44         r = new(char, l+1);
  45         if (!r)
  46                 return NULL;
  47
  48         t = r;
  49
  50         for (f = text; *f; f++, l--) {
  51
  52                 if (percent) {
  53                         if (*f == '%')
  54                                 *(t++) = '%';
  55                         else {
  56                                 const Specifier *i;
  57
  58                                 for (i = table; i->specifier; i++)
  59                                         if (i->specifier == *f)
  60                                                 break;
  61
  62                                 if (i->lookup) {
  63                                         char *n, *w;
  64                                         size_t k, j;
  65
  66                                         w = i->lookup(i->specifier, i->data, userdata);
  67                                         if (!w) {
  68                                                 free(r);
  69                                                 return NULL;
  70                                         }
  71
  72                                         j = t - r;
  73                                         k = strlen(w);
  74
  75                                         n = new(char, j + k + l + 1);
  76                                         if (!n) {
  77                                                 free(r);
  78                                                 free(w);
  79                                                 return NULL;
  80                                         }
  81
  82                                         memcpy(n, r, j);
  83                                         memcpy(n + j, w, k);
  84
  85                                         free(r);
  86                                         free(w);
  87
  88                                         r = n;
  89                                         t = n + j + k;
  90                                 } else {
  91                                         *(t++) = '%';
  92                                         *(t++) = *f;
  93                                 }
  94                         }
  95
  96                         percent = false;
  97                 } else if (*f == '%')
  98                         percent = true;
  99                 else
 100                         *(t++) = *f;
 101         }
 102
 103         *t = 0;
 104         return r;
 105 }
 106
 107 /* Generic handler for simple string replacements */
 108
 109 char* specifier_string(char specifier, void *data, void *userdata) {
 110         return strdup(strempty(data));
 111 }
 112
 113 char *specifier_machine_id(char specifier, void *data, void *userdata) {
 114         sd_id128_t id;
 115         char *buf;
 116         int r;
 117
 118         r = sd_id128_get_machine(&id);
 119         if (r < 0)
 120                 return NULL;
 121
 122         buf = new(char, 33);
 123         if (!buf)
 124                 return NULL;
 125
 126         return sd_id128_to_string(id, buf);
 127 }
 128
 129 char *specifier_boot_id(char specifier, void *data, void *userdata) {
 130         sd_id128_t id;
 131         char *buf;
 132         int r;
 133
 134         r = sd_id128_get_boot(&id);
 135         if (r < 0)
 136                 return NULL;
 137
 138         buf = new(char, 33);
 139         if (!buf)
 140                 return NULL;
 141
 142         return sd_id128_to_string(id, buf);
 143 }
 144
 145 char *specifier_host_name(char specifier, void *data, void *userdata) {
 146         return gethostname_malloc();
 147 }