1 files changed, 62 insertions, 0 deletions

diff --git a/win32/strverscmp.c b/win32/strverscmp.c
new file mode 100644
index 000000000..05dc60c39
--- /dev/null
+++ b/win32/strverscmp.c
@@ -0,0 +1,62 @@
+/*
+        strverscmp from musl (https://www.musl-libc.org/).
+
+        MIT licensed:
+
+----------------------------------------------------------------------
+Copyright © 2005-2020 Rich Felker, et al.
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+----------------------------------------------------------------------
+*/
+#include "libbb.h"
+#include <ctype.h>
+#include <string.h>
+
+int strverscmp(const char *l0, const char *r0)
+{
+        const unsigned char *l = (const void *)l0;
+        const unsigned char *r = (const void *)r0;
+        size_t i, dp, j;
+        int z = 1;
+
+        /* Find maximal matching prefix and track its maximal digit
+         * suffix and whether those digits are all zeros. */
+        for (dp=i=0; l[i]==r[i]; i++) {
+                int c = l[i];
+                if (!c) return 0;
+                if (!isdigit(c)) dp=i+1, z=1;
+                else if (c!='0') z=0;
+        }
+
+        if (l[dp]-'1'<9U && r[dp]-'1'<9U) {
+                /* If we're looking at non-degenerate digit sequences starting
+                 * with nonzero digits, longest digit string is greater. */
+                for (j=i; isdigit(l[j]); j++)
+                        if (!isdigit(r[j])) return 1;
+                if (isdigit(r[j])) return -1;
+        } else if (z && dp<i && (isdigit(l[i]) || isdigit(r[i]))) {
+                /* Otherwise, if common prefix of digit sequence is
+                 * all zeros, digits order less than non-digits. */
+                return (unsigned char)(l[i]-'0') - (unsigned char)(r[i]-'0');
+        }
+
+        return l[i] - r[i];
+}