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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 16:11:47 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 16:11:47 +0000
commit758f820bcc0f68aeebac1717e537ca13a320b909 (patch)
tree48111ece75cf4f98316848b37a7e26356e00669e /lib/filevercmp.h
parentInitial commit. (diff)
downloadcoreutils-upstream.tar.xz
coreutils-upstream.zip
Adding upstream version 9.1.upstream/9.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+/* Compare file names containing version numbers.
+
+ Copyright (C) 1995 Ian Jackson <iwj10@cus.cam.ac.uk>
+ Copyright (C) 2001 Anthony Towns <aj@azure.humbug.org.au>
+ Copyright (C) 2008-2022 Free Software Foundation, Inc.
+
+ This file 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 3 of the
+ License, or (at your option) any later version.
+
+ This file 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 this program. If not, see <https://www.gnu.org/licenses/>. */
+
+#ifndef FILEVERCMP_H
+#define FILEVERCMP_H
+
+#include <stddef.h>
+
+/* Compare strings A and B as file names containing version numbers,
+ and return an integer that is negative, zero, or positive depending
+ on whether A compares less than, equal to, or greater than B.
+
+ Use the following version sort algorithm:
+
+ 1. Compare the strings' maximal-length non-digit prefixes lexically.
+ If there is a difference return that difference.
+ Otherwise discard the prefixes and continue with the next step.
+
+ 2. Compare the strings' maximal-length digit prefixes, using
+ numeric comparison of the numbers represented by each prefix.
+ (Treat an empty prefix as zero; this can happen only at string end.)
+ If there is a difference, return that difference.
+ Otherwise discard the prefixes and continue with the next step.
+
+ 3. If both strings are empty, return 0. Otherwise continue with step 1.
+
+ In version sort, lexical comparison is left to right, byte by byte,
+ using the byte's numeric value (0-255), except that:
+
+ 1. ASCII letters sort before other bytes.
+ 2. A tilde sorts before anything, even an empty string.
+
+ In addition to the version sort rules, the following strings have
+ special priority and sort before all other strings (listed in order):
+
+ 1. The empty string.
+ 2. ".".
+ 3. "..".
+ 4. Strings starting with "." sort before other strings.
+
+ Before comparing two strings where both begin with non-".",
+ or where both begin with "." but neither is "." or "..",
+ suffixes matching the C-locale extended regular expression
+ (\.[A-Za-z~][A-Za-z0-9~]*)*$ are removed and the strings compared
+ without them, using version sort without special priority;
+ if they do not compare equal, this comparison result is used and
+ the suffixes are effectively ignored. Otherwise, the entire
+ strings are compared using version sort.
+
+ This function is intended to be a replacement for strverscmp. */
+int filevercmp (char const *a, char const *b) _GL_ATTRIBUTE_PURE;
+
+/* Like filevercmp, except compare the byte arrays A (of length ALEN)
+ and B (of length BLEN) so that A and B can contain '\0', which
+ sorts just before '\1'. But if ALEN is -1 treat A as a string
+ terminated by '\0', and similarly for BLEN. */
+int filenvercmp (char const *a, ptrdiff_t alen, char const *b, ptrdiff_t blen)
+ _GL_ATTRIBUTE_PURE;
+
+#endif /* FILEVERCMP_H */