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/* SPDX-License-Identifier: LGPL-2.1-or-later */
#if !SD_BOOT
# include <ctype.h>
#endif
#include "macro-fundamental.h"
#include "string-util-fundamental.h"
sd_char *startswith(const sd_char *s, const sd_char *prefix) {
size_t l;
assert(s);
assert(prefix);
l = strlen(prefix);
if (!strneq(s, prefix, l))
return NULL;
return (sd_char*) s + l;
}
sd_char *startswith_no_case(const sd_char *s, const sd_char *prefix) {
size_t l;
assert(s);
assert(prefix);
l = strlen(prefix);
if (!strncaseeq(s, prefix, l))
return NULL;
return (sd_char*) s + l;
}
sd_char* endswith(const sd_char *s, const sd_char *postfix) {
size_t sl, pl;
assert(s);
assert(postfix);
sl = strlen(s);
pl = strlen(postfix);
if (pl == 0)
return (sd_char*) s + sl;
if (sl < pl)
return NULL;
if (strcmp(s + sl - pl, postfix) != 0)
return NULL;
return (sd_char*) s + sl - pl;
}
sd_char* endswith_no_case(const sd_char *s, const sd_char *postfix) {
size_t sl, pl;
assert(s);
assert(postfix);
sl = strlen(s);
pl = strlen(postfix);
if (pl == 0)
return (sd_char*) s + sl;
if (sl < pl)
return NULL;
if (strcasecmp(s + sl - pl, postfix) != 0)
return NULL;
return (sd_char*) s + sl - pl;
}
static bool is_valid_version_char(sd_char a) {
return ascii_isdigit(a) || ascii_isalpha(a) || IN_SET(a, '~', '-', '^', '.');
}
int strverscmp_improved(const sd_char *a, const sd_char *b) {
/* This function is similar to strverscmp(3), but it treats '-' and '.' as separators.
*
* The logic is based on rpm's rpmvercmp(), but unlike rpmvercmp(), it distiguishes e.g.
* '123a' and '123.a', with '123a' being newer.
*
* It allows direct comparison of strings which contain both a version and a release; e.g.
* '247.2-3.1.fc33.x86_64' or '5.11.0-0.rc5.20210128git76c057c84d28.137.fc34'.
*
* The input string is split into segments. Each segment is numeric or alphabetic, and may be
* prefixed with the following:
* '~' : used for pre-releases, a segment prefixed with this is the oldest,
* '-' : used for the separator between version and release,
* '^' : used for patched releases, a segment with this is newer than one with '-'.
* '.' : used for point releases.
* Note that no prefix segment is the newest. All non-supported characters are dropped, and
* handled as a separator of segments, e.g., '123_a' is equivalent to '123a'.
*
* By using this, version strings can be sorted like following:
* (older) 122.1
* ^ 123~rc1-1
* | 123
* | 123-a
* | 123-a.1
* | 123-1
* | 123-1.1
* | 123^post1
* | 123.a-1
* | 123.1-1
* v 123a-1
* (newer) 124-1
*/
a = strempty(a);
b = strempty(b);
for (;;) {
const sd_char *aa, *bb;
int r;
/* Drop leading invalid characters. */
while (*a != '\0' && !is_valid_version_char(*a))
a++;
while (*b != '\0' && !is_valid_version_char(*b))
b++;
/* Handle '~'. Used for pre-releases, e.g. 123~rc1, or 4.5~alpha1 */
if (*a == '~' || *b == '~') {
/* The string prefixed with '~' is older. */
r = CMP(*a != '~', *b != '~');
if (r != 0)
return r;
/* Now both strings are prefixed with '~'. Compare remaining strings. */
a++;
b++;
}
/* If at least one string reaches the end, then longer is newer.
* Note that except for '~' prefixed segments, a string which has more segments is newer.
* So, this check must be after the '~' check. */
if (*a == '\0' || *b == '\0')
return CMP(*a, *b);
/* Handle '-', which separates version and release, e.g 123.4-3.1.fc33.x86_64 */
if (*a == '-' || *b == '-') {
/* The string prefixed with '-' is older (e.g., 123-9 vs 123.1-1) */
r = CMP(*a != '-', *b != '-');
if (r != 0)
return r;
a++;
b++;
}
/* Handle '^'. Used for patched release. */
if (*a == '^' || *b == '^') {
r = CMP(*a != '^', *b != '^');
if (r != 0)
return r;
a++;
b++;
}
/* Handle '.'. Used for point releases. */
if (*a == '.' || *b == '.') {
r = CMP(*a != '.', *b != '.');
if (r != 0)
return r;
a++;
b++;
}
if (ascii_isdigit(*a) || ascii_isdigit(*b)) {
/* Find the leading numeric segments. One may be an empty string. So,
* numeric segments are always newer than alpha segments. */
for (aa = a; ascii_isdigit(*aa); aa++)
;
for (bb = b; ascii_isdigit(*bb); bb++)
;
/* Check if one of the strings was empty, but the other not. */
r = CMP(a != aa, b != bb);
if (r != 0)
return r;
/* Skip leading '0', to make 00123 equivalent to 123. */
while (*a == '0')
a++;
while (*b == '0')
b++;
/* To compare numeric segments without parsing their values, first compare the
* lengths of the segments. Eg. 12345 vs 123, longer is newer. */
r = CMP(aa - a, bb - b);
if (r != 0)
return r;
/* Then, compare them as strings. */
r = CMP(strncmp(a, b, aa - a), 0);
if (r != 0)
return r;
} else {
/* Find the leading non-numeric segments. */
for (aa = a; ascii_isalpha(*aa); aa++)
;
for (bb = b; ascii_isalpha(*bb); bb++)
;
/* Note that the segments are usually not NUL-terminated. */
r = CMP(strncmp(a, b, MIN(aa - a, bb - b)), 0);
if (r != 0)
return r;
/* Longer is newer, e.g. abc vs abcde. */
r = CMP(aa - a, bb - b);
if (r != 0)
return r;
}
/* The current segments are equivalent. Let's move to the next one. */
a = aa;
b = bb;
}
}
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