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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:35:18 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:35:18 +0000 |
commit | b750101eb236130cf056c675997decbac904cc49 (patch) | |
tree | a5df1a06754bdd014cb975c051c83b01c9a97532 /src/basic/replace-var.c | |
parent | Initial commit. (diff) | |
download | systemd-upstream.tar.xz systemd-upstream.zip |
Adding upstream version 252.22.upstream/252.22upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/basic/replace-var.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/src/basic/replace-var.c b/src/basic/replace-var.c new file mode 100644 index 0000000..01c26ce --- /dev/null +++ b/src/basic/replace-var.c @@ -0,0 +1,93 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <stddef.h> +#include <stdlib.h> + +#include "alloc-util.h" +#include "macro.h" +#include "replace-var.h" +#include "string-util.h" + +/* + * Generic infrastructure for replacing @FOO@ style variables in + * strings. Will call a callback for each replacement. + */ + +static int get_variable(const char *b, char **r) { + size_t k; + char *t; + + assert(b); + assert(r); + + if (*b != '@') + return 0; + + k = strspn(b + 1, UPPERCASE_LETTERS "_"); + if (k <= 0 || b[k+1] != '@') + return 0; + + t = strndup(b + 1, k); + if (!t) + return -ENOMEM; + + *r = t; + return 1; +} + +char *replace_var(const char *text, char *(*lookup)(const char *variable, void *userdata), void *userdata) { + char *r, *t; + const char *f; + size_t l; + + assert(text); + assert(lookup); + + l = strlen(text); + r = new(char, l+1); + if (!r) + return NULL; + + f = text; + t = r; + while (*f) { + _cleanup_free_ char *v = NULL, *n = NULL; + char *a; + int k; + size_t skip, d, nl; + + k = get_variable(f, &v); + if (k < 0) + goto oom; + if (k == 0) { + *(t++) = *(f++); + continue; + } + + n = lookup(v, userdata); + if (!n) + goto oom; + + skip = strlen(v) + 2; + + d = t - r; + nl = l - skip + strlen(n); + a = realloc(r, nl + 1); + if (!a) + goto oom; + + l = nl; + r = a; + t = r + d; + + t = stpcpy(t, n); + f += skip; + } + + *t = 0; + return r; + +oom: + return mfree(r); +} |