diff options
Diffstat (limited to 'src/shared')
| -rw-r--r-- | src/shared/replace-var.c | 110 | ||||
| -rw-r--r-- | src/shared/replace-var.h | 24 |
2 files changed, 134 insertions, 0 deletions
diff --git a/src/shared/replace-var.c b/src/shared/replace-var.c new file mode 100644 index 0000000000..e11c57a43d --- /dev/null +++ b/src/shared/replace-var.c @@ -0,0 +1,110 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2012 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <string.h> + +#include "macro.h" +#include "util.h" +#include "replace-var.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, "ABCDEFGHIJKLMNOPQRSTUVWXYZ_"); + 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: + free(r); + return NULL; +} diff --git a/src/shared/replace-var.h b/src/shared/replace-var.h new file mode 100644 index 0000000000..7eaee93a3e --- /dev/null +++ b/src/shared/replace-var.h @@ -0,0 +1,24 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +#pragma once + +/*** + This file is part of systemd. + + Copyright 2012 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +char *replace_var(const char *text, char *(*lookup)(const char *variable, void*userdata), void *userdata); |