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Commit | Line | Data |
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52ad194e | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
663996b3 MS |
2 | /*** |
3 | This file is part of systemd. | |
4 | ||
5 | Copyright 2012 Lennart Poettering | |
6 | ||
7 | systemd is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU Lesser General Public License as published by | |
9 | the Free Software Foundation; either version 2.1 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | systemd is distributed in the hope that it will be useful, but | |
13 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | Lesser General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU Lesser General Public License | |
18 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
19 | ***/ | |
20 | ||
4c89c718 MP |
21 | #include <errno.h> |
22 | #include <stddef.h> | |
23 | #include <stdlib.h> | |
663996b3 MS |
24 | #include <string.h> |
25 | ||
db2df898 | 26 | #include "alloc-util.h" |
663996b3 | 27 | #include "macro.h" |
663996b3 | 28 | #include "replace-var.h" |
db2df898 | 29 | #include "string-util.h" |
663996b3 MS |
30 | |
31 | /* | |
32 | * Generic infrastructure for replacing @FOO@ style variables in | |
33 | * strings. Will call a callback for each replacement. | |
34 | */ | |
35 | ||
36 | static int get_variable(const char *b, char **r) { | |
37 | size_t k; | |
38 | char *t; | |
39 | ||
40 | assert(b); | |
41 | assert(r); | |
42 | ||
43 | if (*b != '@') | |
44 | return 0; | |
45 | ||
14228c0d | 46 | k = strspn(b + 1, UPPERCASE_LETTERS "_"); |
663996b3 MS |
47 | if (k <= 0 || b[k+1] != '@') |
48 | return 0; | |
49 | ||
50 | t = strndup(b + 1, k); | |
51 | if (!t) | |
52 | return -ENOMEM; | |
53 | ||
54 | *r = t; | |
55 | return 1; | |
56 | } | |
57 | ||
f5e65279 | 58 | char *replace_var(const char *text, char *(*lookup)(const char *variable, void *userdata), void *userdata) { |
663996b3 MS |
59 | char *r, *t; |
60 | const char *f; | |
61 | size_t l; | |
62 | ||
63 | assert(text); | |
64 | assert(lookup); | |
65 | ||
66 | l = strlen(text); | |
67 | r = new(char, l+1); | |
68 | if (!r) | |
69 | return NULL; | |
70 | ||
71 | f = text; | |
72 | t = r; | |
73 | while (*f) { | |
74 | _cleanup_free_ char *v = NULL, *n = NULL; | |
75 | char *a; | |
76 | int k; | |
77 | size_t skip, d, nl; | |
78 | ||
79 | k = get_variable(f, &v); | |
80 | if (k < 0) | |
81 | goto oom; | |
82 | if (k == 0) { | |
83 | *(t++) = *(f++); | |
84 | continue; | |
85 | } | |
86 | ||
87 | n = lookup(v, userdata); | |
88 | if (!n) | |
89 | goto oom; | |
90 | ||
91 | skip = strlen(v) + 2; | |
92 | ||
93 | d = t - r; | |
94 | nl = l - skip + strlen(n); | |
95 | a = realloc(r, nl + 1); | |
96 | if (!a) | |
97 | goto oom; | |
98 | ||
99 | l = nl; | |
100 | r = a; | |
101 | t = r + d; | |
102 | ||
103 | t = stpcpy(t, n); | |
104 | f += skip; | |
105 | } | |
106 | ||
107 | *t = 0; | |
108 | return r; | |
109 | ||
110 | oom: | |
8a584da2 | 111 | return mfree(r); |
663996b3 | 112 | } |