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Commit | Line | Data |
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db9ecf05 | 1 | /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
6e6fb527 | 2 | |
11c3a366 TA |
3 | #include <errno.h> |
4 | #include <stddef.h> | |
5 | #include <stdlib.h> | |
6e6fb527 | 6 | |
b5efdb8a | 7 | #include "alloc-util.h" |
6e6fb527 | 8 | #include "macro.h" |
6e6fb527 | 9 | #include "replace-var.h" |
b11d6a7b | 10 | #include "string-util.h" |
6e6fb527 LP |
11 | |
12 | /* | |
13 | * Generic infrastructure for replacing @FOO@ style variables in | |
14 | * strings. Will call a callback for each replacement. | |
15 | */ | |
16 | ||
17 | static int get_variable(const char *b, char **r) { | |
18 | size_t k; | |
19 | char *t; | |
20 | ||
21 | assert(b); | |
22 | assert(r); | |
23 | ||
24 | if (*b != '@') | |
25 | return 0; | |
26 | ||
4b549144 | 27 | k = strspn(b + 1, UPPERCASE_LETTERS "_"); |
6e6fb527 LP |
28 | if (k <= 0 || b[k+1] != '@') |
29 | return 0; | |
30 | ||
31 | t = strndup(b + 1, k); | |
32 | if (!t) | |
33 | return -ENOMEM; | |
34 | ||
35 | *r = t; | |
36 | return 1; | |
37 | } | |
38 | ||
2d5dece8 | 39 | char *replace_var(const char *text, char *(*lookup)(const char *variable, void *userdata), void *userdata) { |
6e6fb527 LP |
40 | char *r, *t; |
41 | const char *f; | |
42 | size_t l; | |
43 | ||
44 | assert(text); | |
45 | assert(lookup); | |
46 | ||
47 | l = strlen(text); | |
48 | r = new(char, l+1); | |
49 | if (!r) | |
50 | return NULL; | |
51 | ||
52 | f = text; | |
53 | t = r; | |
54 | while (*f) { | |
55 | _cleanup_free_ char *v = NULL, *n = NULL; | |
56 | char *a; | |
57 | int k; | |
58 | size_t skip, d, nl; | |
59 | ||
60 | k = get_variable(f, &v); | |
61 | if (k < 0) | |
62 | goto oom; | |
63 | if (k == 0) { | |
64 | *(t++) = *(f++); | |
65 | continue; | |
66 | } | |
67 | ||
68 | n = lookup(v, userdata); | |
69 | if (!n) | |
70 | goto oom; | |
71 | ||
72 | skip = strlen(v) + 2; | |
73 | ||
74 | d = t - r; | |
75 | nl = l - skip + strlen(n); | |
76 | a = realloc(r, nl + 1); | |
77 | if (!a) | |
78 | goto oom; | |
79 | ||
80 | l = nl; | |
81 | r = a; | |
82 | t = r + d; | |
83 | ||
84 | t = stpcpy(t, n); | |
85 | f += skip; | |
86 | } | |
87 | ||
88 | *t = 0; | |
89 | return r; | |
90 | ||
91 | oom: | |
6b430fdb | 92 | return mfree(r); |
6e6fb527 | 93 | } |