Move strnatcmp.{h,c} from epan into wsutil: there's nothing epan-specific

there and moving it avoids having to recompile the file for use in editcap
and mergecap (which don't link against libwireshark).

svn path=/trunk/; revision=50650

1 files changed, 202 insertions, 0 deletions

diff --git a/wsutil/strnatcmp.c b/wsutil/strnatcmp.c
new file mode 100644
index 0000000000..ee4d14e8cc
--- /dev/null
+++ b/wsutil/strnatcmp.c
@@ -0,0 +1,202 @@
+/* strnatcmp.c
+ *
+ * $Id$
+ *
+ * Original code downloaded from: http://sourcefrog.net/projects/natsort/
+
+  strnatcmp.c -- Perform 'natural order' comparisons of strings in C.
+  Copyright (C) 2000, 2004 by Martin Pool <mbp sourcefrog net>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+
+
+/* partial change history:
+ *
+ * 2004-10-10 mbp: Lift out character type dependencies into macros.
+ *
+ * Eric Sosman pointed out that ctype functions take a parameter whose
+ * value must be that of an unsigned int, even on platforms that have
+ * negative chars in their default char type.
+ */
+
+#include <ctype.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "strnatcmp.h"
+
+
+/* These are defined as macros to make it easier to adapt this code to
+ * different characters types or comparison functions. */
+static int
+nat_isdigit(nat_char a)
+{
+    return isdigit((unsigned char) a);
+}
+
+
+static int
+nat_isspace(nat_char a)
+{
+    return isspace((unsigned char) a);
+}
+
+
+static nat_char
+nat_toupper(nat_char a)
+{
+    return toupper((unsigned char) a);
+}
+
+
+static int
+compare_right(nat_char const *a, nat_char const *b)
+{
+    int bias = 0;
+
+    /* The longest run of digits wins.  That aside, the greatest
+       value wins, but we can't know that it will until we've scanned
+       both numbers to know that they have the same magnitude, so we
+       remember it in BIAS. */
+    for (;; a++, b++) {
+        if (!nat_isdigit(*a)  &&  !nat_isdigit(*b))
+            return bias;
+        else if (!nat_isdigit(*a))
+            return -1;
+        else if (!nat_isdigit(*b))
+            return +1;
+        else if (*a < *b) {
+            if (!bias)
+                bias = -1;
+        } else if (*a > *b) {
+            if (!bias)
+                bias = +1;
+        } else if (!*a  &&  !*b)
+            return bias;
+    }
+
+    return 0;
+}
+
+
+static int
+compare_left(nat_char const *a, nat_char const *b)
+{
+    /* Compare two left-aligned numbers: the first to have a
+       different value wins. */
+    for (;; a++, b++) {
+        if (!nat_isdigit(*a)  &&  !nat_isdigit(*b))
+            return 0;
+        else if (!nat_isdigit(*a))
+            return -1;
+        else if (!nat_isdigit(*b))
+            return +1;
+        else if (*a < *b)
+            return -1;
+        else if (*a > *b)
+            return +1;
+    }
+
+    return 0;
+}
+
+
+static int strnatcmp0(nat_char const *a, nat_char const *b, int fold_case)
+{
+    int ai, bi;
+    nat_char ca, cb;
+    int fractional, result;
+
+    if (!a || !b) {
+        if (!a && !b)
+            return 0;
+        if (!a)
+            return -1;
+        return +1;
+    }
+    ai = bi = 0;
+    while (1) {
+        ca = a[ai]; cb = b[bi];
+
+        /* skip over leading spaces or zeros */
+        while (nat_isspace(ca))
+            ca = a[++ai];
+
+        while (nat_isspace(cb))
+            cb = b[++bi];
+
+        /* process run of digits */
+        if (nat_isdigit(ca)  &&  nat_isdigit(cb)) {
+            fractional = (ca == '0' || cb == '0');
+
+            if (fractional) {
+                if ((result = compare_left(a+ai, b+bi)) != 0)
+                    return result;
+            } else {
+                if ((result = compare_right(a+ai, b+bi)) != 0)
+                    return result;
+            }
+        }
+
+        if (!ca && !cb) {
+            /* The strings compare the same.  Perhaps the caller
+               will want to call strcmp to break the tie. */
+            return 0;
+        }
+
+        if (fold_case) {
+            ca = nat_toupper(ca);
+            cb = nat_toupper(cb);
+        }
+
+        if (ca < cb)
+            return -1;
+        else if (ca > cb)
+            return +1;
+
+        ++ai; ++bi;
+    }
+}
+
+
+int strnatcmp(nat_char const *a, nat_char const *b)
+{
+    return strnatcmp0(a, b, 0);
+}
+
+
+/* Compare, recognizing numeric string and ignoring case. */
+int strnatcasecmp(nat_char const *a, nat_char const *b)
+{
+    return strnatcmp0(a, b, 1);
+}
+
+
+/*
+ * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * vi: set shiftwidth=4 tabstop=4 expandtab:
+ * :indentSize=4:tabSize=4:noTabs=true:
+ */
+