sort: add support for sorting version strings

Add an implementation of strverscmp from musl so that the 'sort -V'
option works.

Add '-V' to the trivial usage message.

Costs 248-256 bytes.

(GitHub issue #370)

5 files changed, 69 insertions, 1 deletions

diff --git a/coreutils/sort.c b/coreutils/sort.c
index 2e952f81c..949948203 100644
--- a/coreutils/sort.c
+++ b/coreutils/sort.c
@@ -43,7 +43,12 @@
 
 //usage:#define sort_trivial_usage
 //usage:       "[-nru"
+//usage:        IF_NOT_PLATFORM_MINGW32(
 //usage:        IF_FEATURE_SORT_BIG("ghMcszbdfiokt] [-o FILE] [-k START[.OFS][OPTS][,END[.OFS][OPTS]] [-t CHAR")
+//usage:        )
+//usage:        IF_PLATFORM_MINGW32(
+//usage:        IF_FEATURE_SORT_BIG("ghMVcszbdfiokt] [-o FILE] [-k START[.OFS][OPTS][,END[.OFS][OPTS]] [-t CHAR")
+//usage:        )
 //usage:       "] [FILE]..."
 //usage:#define sort_full_usage "\n\n"
 //usage:       "Sort lines of text\n"
diff --git a/include/mingw.h b/include/mingw.h
index 6ed9bed4a..f6f0bf262 100644
--- a/include/mingw.h
+++ b/include/mingw.h
@@ -228,6 +228,7 @@ int unsetenv(const char *env);
 char *strndup(char const *s, size_t n);
 char *mingw_strerror(int errnum);
 char *strsignal(int sig);
+int strverscmp(const char *s1, const char *s2);
 
 #define strerror mingw_strerror
 
diff --git a/include/platform.h b/include/platform.h
index 8ae5ed4bc..5795a0cf3 100644
--- a/include/platform.h
+++ b/include/platform.h
@@ -476,7 +476,6 @@ typedef unsigned smalluint;
 # undef HAVE_STRCASESTR
 # undef HAVE_STRCHRNUL
 # undef HAVE_STRSEP
-# undef HAVE_STRVERSCMP
 #if !defined(__MINGW64_VERSION_MAJOR)
 # undef HAVE_VASPRINTF
 #endif
diff --git a/win32/Kbuild b/win32/Kbuild
index 3e1f845df..e705dae66 100644
--- a/win32/Kbuild
+++ b/win32/Kbuild
@@ -25,6 +25,7 @@ lib-$(CONFIG_FEATURE_PRNG_SHELL) += sh_random.o
 lib-$(CONFIG_PLATFORM_MINGW32) += statfs.o
 lib-$(CONFIG_PLATFORM_MINGW32) += strndup.o
 lib-$(CONFIG_PLATFORM_MINGW32) += strptime.o
+lib-$(CONFIG_PLATFORM_MINGW32) += strverscmp.o
 lib-$(CONFIG_PLATFORM_MINGW32) += system.o
 lib-$(CONFIG_PLATFORM_MINGW32) += termios.o
 lib-$(CONFIG_PLATFORM_MINGW32) += timegm.o
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];
+}