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/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include "nulstr-util.h"
#include "string-util.h"
#include "strv.h"
char** strv_parse_nulstr_full(const char *s, size_t l, bool drop_trailing_nuls) {
/* l is the length of the input data, which will be split at NULs into elements of the resulting
* strv. Hence, the number of items in the resulting strv will be equal to one plus the number of NUL
* bytes in the l bytes starting at s, unless s[l-1] is NUL, in which case the final empty string is
* not stored in the resulting strv, and length is equal to the number of NUL bytes.
*
* Note that contrary to a normal nulstr which cannot contain empty strings, because the input data
* is terminated by any two consequent NUL bytes, this parser accepts empty strings in s. */
_cleanup_strv_free_ char **v = NULL;
size_t c = 0, i = 0;
assert(s || l <= 0);
if (drop_trailing_nuls)
while (l > 0 && s[l-1] == '\0')
l--;
if (l <= 0)
return new0(char*, 1);
for (const char *p = s; p < s + l; p++)
if (*p == 0)
c++;
if (s[l-1] != 0)
c++;
v = new0(char*, c+1);
if (!v)
return NULL;
for (const char *p = s; p < s + l; ) {
const char *e;
e = memchr(p, 0, s + l - p);
v[i] = memdup_suffix0(p, e ? e - p : s + l - p);
if (!v[i])
return NULL;
i++;
if (!e)
break;
p = e + 1;
}
assert(i == c);
return TAKE_PTR(v);
}
char** strv_split_nulstr(const char *s) {
_cleanup_strv_free_ char **l = NULL;
/* This parses a nulstr, without specification of size, and stops at an empty string. This cannot
* parse nulstrs with embedded empty strings hence, as an empty string is an end marker. Use
* strv_parse_nulstr() above to parse a nulstr with embedded empty strings (which however requires a
* size to be specified) */
NULSTR_FOREACH(i, s)
if (strv_extend(&l, i) < 0)
return NULL;
return l ? TAKE_PTR(l) : strv_new(NULL);
}
int strv_make_nulstr(char * const *l, char **ret, size_t *ret_size) {
/* Builds a nulstr and returns it together with the size. An extra NUL byte will be appended (⚠️ but
* not included in the size! ⚠️). This is done so that the nulstr can be used both in
* strv_parse_nulstr() and in NULSTR_FOREACH()/strv_split_nulstr() contexts, i.e. with and without a
* size parameter. In the former case we can include empty strings, in the latter case we cannot (as
* that is the end marker).
*
* When NULSTR_FOREACH()/strv_split_nulstr() is used it is often assumed that the nulstr ends in two
* NUL bytes (which it will, if not empty). To ensure that this assumption *always* holds, we'll
* return a buffer with two NUL bytes in that case, but return a size of zero. */
_cleanup_free_ char *m = NULL;
size_t n = 0;
assert(ret);
STRV_FOREACH(i, l) {
size_t z;
z = strlen(*i);
if (!GREEDY_REALLOC(m, n + z + 2))
return -ENOMEM;
memcpy(m + n, *i, z + 1);
n += z + 1;
}
if (!m) {
/* return a buffer with an extra NUL, so that the assumption that we always have two trailing NULs holds */
m = new0(char, 2);
if (!m)
return -ENOMEM;
n = 0;
} else
/* Make sure there is a second extra NUL at the end of resulting nulstr (not counted in return size) */
m[n] = '\0';
*ret = TAKE_PTR(m);
if (ret_size)
*ret_size = n;
return 0;
}
int set_make_nulstr(Set *s, char **ret, size_t *ret_size) {
/* Use _cleanup_free_ instead of _cleanup_strv_free_ because we need to clean the strv only, not
* the strings owned by the set. */
_cleanup_free_ char **strv = NULL;
assert(ret);
strv = set_get_strv(s);
if (!strv)
return -ENOMEM;
return strv_make_nulstr(strv, ret, ret_size);
}
const char* nulstr_get(const char *nulstr, const char *needle) {
if (!nulstr)
return NULL;
NULSTR_FOREACH(i, nulstr)
if (streq(i, needle))
return i;
return NULL;
}
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