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-rw-r--r--src/fundamental/string-util-fundamental.c230
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diff --git a/src/fundamental/string-util-fundamental.c b/src/fundamental/string-util-fundamental.c
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+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#ifndef 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;
+}
+
+#ifndef SD_BOOT
+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;
+}
+#endif
+
+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;
+ }
+}