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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
6e6fb527 LP |
2 | /*** |
3 | This file is part of systemd. | |
4 | ||
5 | Copyright 2012 Lennart Poettering | |
6e6fb527 LP |
6 | ***/ |
7 | ||
11c3a366 TA |
8 | #include <errno.h> |
9 | #include <stddef.h> | |
10 | #include <stdlib.h> | |
6e6fb527 LP |
11 | #include <string.h> |
12 | ||
b5efdb8a | 13 | #include "alloc-util.h" |
6e6fb527 | 14 | #include "macro.h" |
6e6fb527 | 15 | #include "replace-var.h" |
b11d6a7b | 16 | #include "string-util.h" |
6e6fb527 LP |
17 | |
18 | /* | |
19 | * Generic infrastructure for replacing @FOO@ style variables in | |
20 | * strings. Will call a callback for each replacement. | |
21 | */ | |
22 | ||
23 | static int get_variable(const char *b, char **r) { | |
24 | size_t k; | |
25 | char *t; | |
26 | ||
27 | assert(b); | |
28 | assert(r); | |
29 | ||
30 | if (*b != '@') | |
31 | return 0; | |
32 | ||
4b549144 | 33 | k = strspn(b + 1, UPPERCASE_LETTERS "_"); |
6e6fb527 LP |
34 | if (k <= 0 || b[k+1] != '@') |
35 | return 0; | |
36 | ||
37 | t = strndup(b + 1, k); | |
38 | if (!t) | |
39 | return -ENOMEM; | |
40 | ||
41 | *r = t; | |
42 | return 1; | |
43 | } | |
44 | ||
2d5dece8 | 45 | char *replace_var(const char *text, char *(*lookup)(const char *variable, void *userdata), void *userdata) { |
6e6fb527 LP |
46 | char *r, *t; |
47 | const char *f; | |
48 | size_t l; | |
49 | ||
50 | assert(text); | |
51 | assert(lookup); | |
52 | ||
53 | l = strlen(text); | |
54 | r = new(char, l+1); | |
55 | if (!r) | |
56 | return NULL; | |
57 | ||
58 | f = text; | |
59 | t = r; | |
60 | while (*f) { | |
61 | _cleanup_free_ char *v = NULL, *n = NULL; | |
62 | char *a; | |
63 | int k; | |
64 | size_t skip, d, nl; | |
65 | ||
66 | k = get_variable(f, &v); | |
67 | if (k < 0) | |
68 | goto oom; | |
69 | if (k == 0) { | |
70 | *(t++) = *(f++); | |
71 | continue; | |
72 | } | |
73 | ||
74 | n = lookup(v, userdata); | |
75 | if (!n) | |
76 | goto oom; | |
77 | ||
78 | skip = strlen(v) + 2; | |
79 | ||
80 | d = t - r; | |
81 | nl = l - skip + strlen(n); | |
82 | a = realloc(r, nl + 1); | |
83 | if (!a) | |
84 | goto oom; | |
85 | ||
86 | l = nl; | |
87 | r = a; | |
88 | t = r + d; | |
89 | ||
90 | t = stpcpy(t, n); | |
91 | f += skip; | |
92 | } | |
93 | ||
94 | *t = 0; | |
95 | return r; | |
96 | ||
97 | oom: | |
6b430fdb | 98 | return mfree(r); |
6e6fb527 | 99 | } |