blob: 383e390577d2e5dd481bdfeb508df02820e17f03 [file] [log] [blame]
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#ifndef SD_BOOT
#include <ctype.h>
#include "macro.h"
#endif
#include "string-util-fundamental.h"
sd_char *startswith(const sd_char *s, const sd_char *prefix) {
sd_size_t l;
assert(s);
assert(prefix);
l = strlen(prefix);
if (!strneq(s, prefix, l))
return NULL;
return (sd_char*) s + l;
}
#ifndef SD_BOOT
sd_char *startswith_no_case(const sd_char *s, const sd_char *prefix) {
sd_size_t l;
assert(s);
assert(prefix);
l = strlen(prefix);
if (!strncaseeq(s, prefix, l))
return NULL;
return (sd_char*) s + l;
}
#endif
sd_char* endswith(const sd_char *s, const sd_char *postfix) {
sd_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) {
sd_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;
}
#ifdef SD_BOOT
static sd_bool isdigit(sd_char a) {
return a >= '0' && a <= '9';
}
#endif
static sd_bool is_alpha(sd_char a) {
/* Locale independent version of isalpha(). */
return (a >= 'a' && a <= 'z') || (a >= 'A' && a <= 'Z');
}
static sd_bool is_valid_version_char(sd_char a) {
return isdigit(a) || is_alpha(a) || IN_SET(a, '~', '-', '^', '.');
}
sd_int strverscmp_improved(const sd_char *a, const sd_char *b) {
/* This is based on RPM's rpmvercmp(). But this explicitly handles '-' and '.', as we usually
* want to directly compare strings which contain both version and release; e.g.
* '247.2-3.1.fc33.x86_64' or '5.11.0-0.rc5.20210128git76c057c84d28.137.fc34'.
* Unlike rpmvercmp(), this distiguishes e.g. 123a and 123.a, and 123a is newer.
*
* This splits the input strings into segments. Each segment is numeric or alpha, 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, 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
*/
if (isempty(a) || isempty(b))
return strcmp_ptr(a, b);
for (;;) {
const sd_char *aa, *bb;
sd_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 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 (isdigit(*a) || isdigit(*b)) {
/* Skip leading '0', to make 00123 equivalent to 123. */
while (*a == '0')
a++;
while (*b == '0')
b++;
/* Find the leading numeric segments. One may be an empty string. So,
* numeric segments are always newer than alpha segments. */
for (aa = a; isdigit(*aa); aa++)
;
for (bb = b; isdigit(*bb); bb++)
;
/* 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 = strncmp(a, b, aa - a);
if (r != 0)
return r;
} else {
/* Find the leading non-numeric segments. */
for (aa = a; is_alpha(*aa); aa++)
;
for (bb = b; is_alpha(*bb); bb++)
;
/* Note that the segments are usually not NUL-terminated. */
r = strncmp(a, b, MIN(aa - a, bb - b));
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 compare the next one. */
a = aa;
b = bb;
}
}