Imported Upstream version 93u+upstream

1 files changed, 226 insertions, 0 deletions

diff --git a/src/lib/libast/string/fmtre.c b/src/lib/libast/string/fmtre.c
new file mode 100644
index 0000000..a4a887b
--- /dev/null
+++ b/src/lib/libast/string/fmtre.c
@@ -0,0 +1,226 @@
+/***********************************************************************
+*                                                                      *
+*               This software is part of the ast package               *
+*          Copyright (c) 1985-2011 AT&T Intellectual Property          *
+*                      and is licensed under the                       *
+*                 Eclipse Public License, Version 1.0                  *
+*                    by AT&T Intellectual Property                     *
+*                                                                      *
+*                A copy of the License is available at                 *
+*          http://www.eclipse.org/org/documents/epl-v10.html           *
+*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
+*                                                                      *
+*              Information and Software Systems Research               *
+*                            AT&T Research                             *
+*                           Florham Park NJ                            *
+*                                                                      *
+*                 Glenn Fowler <gsf@research.att.com>                  *
+*                  David Korn <dgk@research.att.com>                   *
+*                   Phong Vo <kpv@research.att.com>                    *
+*                                                                      *
+***********************************************************************/
+#pragma prototyped
+
+/*
+ * Glenn Fowler
+ * AT&T Research
+ *
+ * return RE expression given strmatch() pattern
+ * 0 returned for invalid RE
+ */
+
+#include <ast.h>
+
+typedef struct Stack_s
+{
+	char*		beg;
+	short		len;
+	short		min;
+} Stack_t;
+
+char*
+fmtre(const char* as)
+{
+	register char*		s = (char*)as;
+	register int		c;
+	register char*		t;
+	register Stack_t*	p;
+	char*			x;
+	int			n;
+	int			end;
+	char*			buf;
+	Stack_t			stack[32];
+
+	end = 1;
+	c = 2 * strlen(s) + 1;
+	t = buf = fmtbuf(c);
+	p = stack;
+	if (*s != '*' || *(s + 1) == '(' || *(s + 1) == '-' && *(s + 2) == '(')
+		*t++ = '^';
+	else
+		s++;
+	for (;;)
+	{
+		switch (c = *s++)
+		{
+		case 0:
+			break;
+		case '\\':
+			if (!(c = *s++) || c == '{' || c == '}')
+				return 0;
+			*t++ = '\\';
+			if ((*t++ = c) == '(' && *s == '|')
+			{
+				*t++ = *s++;
+				goto logical;
+			}
+			continue;
+		case '[':
+			*t++ = c;
+			n = 0;
+			if ((c = *s++) == '!')
+			{
+				*t++ = '^';
+				c = *s++;
+			}
+			else if (c == '^')
+			{
+				if ((c = *s++) == ']')
+				{
+					*(t - 1) = '\\';
+					*t++ = '^';
+					continue;
+				}
+				n = '^';
+			}
+			for (;;)
+			{
+				if (!(*t++ = c))
+					return 0;
+				if ((c = *s++) == ']')
+				{
+					if (n)
+						*t++ = n;
+					*t++ = c;
+					break;
+				}
+			}
+			continue;
+		case '{':
+			for (x = s; *x && *x != '}'; x++);
+			if (*x++ && (*x == '(' || *x == '-' && *(x + 1) == '('))
+			{
+				if (p >= &stack[elementsof(stack)])
+					return 0;
+				p->beg = s - 1;
+				s = x;
+				p->len = s - p->beg;
+				if (p->min = *s == '-')
+					s++;
+				p++;
+				*t++ = *s++;
+			}
+			else
+				*t++ = c;
+			continue;
+		case '*':
+			if (!*s)
+			{
+				end = 0;
+				break;
+			}
+			/*FALLTHROUGH*/
+		case '?':
+		case '+':
+		case '@':
+		case '!':
+		case '~':
+			if (*s == '(' || c != '~' && *s == '-' && *(s + 1) == '(')
+			{
+				if (p >= &stack[elementsof(stack)])
+					return 0;
+				p->beg = s - 1;
+				if (c == '~')
+				{
+					if (*(s + 1) == 'E' && *(s + 2) == ')')
+					{
+						for (s += 3; *t = *s; t++, s++);
+						continue;
+					}
+					p->len = 0;
+					p->min = 0;
+					*t++ = *s++;
+					*t++ = '?';
+				}
+				else
+				{
+					p->len = c != '@';
+					if (p->min = *s == '-')
+						s++;
+					*t++ = *s++;
+				}
+				p++;
+			}
+			else
+			{
+				switch (c)
+				{
+				case '*':
+					*t++ = '.';
+					break;
+				case '?':
+					c = '.';
+					break;
+				case '+':
+				case '!':
+					*t++ = '\\';
+					break;
+				}
+				*t++ = c;
+			}
+			continue;
+		case '(':
+			if (p >= &stack[elementsof(stack)])
+				return 0;
+			p->beg = s - 1;
+			p->len = 0;
+			p->min = 0;
+			p++;
+			*t++ = c;
+			continue;
+		case ')':
+			if (p == stack)
+				return 0;
+			*t++ = c;
+			p--;
+			for (c = 0; c < p->len; c++)
+				*t++ = p->beg[c];
+			if (p->min)
+				*t++ = '?';
+			continue;
+		case '^':
+		case '.':
+		case '$':
+			*t++ = '\\';
+			*t++ = c;
+			continue;
+		case '|':
+			if (t == buf || *(t - 1) == '(')
+				return 0;
+		logical:
+			if (!*s || *s == ')')
+				return 0;
+			/*FALLTHROUGH*/
+		default:
+			*t++ = c;
+			continue;
+		}
+		break;
+	}
+	if (p != stack)
+		return 0;
+	if (end)
+		*t++ = '$';
+	*t = 0;
+	return buf;
+}