Index: bin/sh/options.h
===================================================================
--- bin/sh/options.h
+++ bin/sh/options.h
@@ -68,9 +68,10 @@
 #define	nologflag optval[19]
 #define	pipefailflag optval[20]
 #define	verifyflag optval[21]
+#define	braceexpandflag optval[22]
 
 #define NSHORTOPTS	19
-#define NOPTS		22
+#define NOPTS		23
 
 extern char optval[NOPTS];
 extern const char optletter[NSHORTOPTS];
@@ -100,6 +101,7 @@
 	"\005nolog"
 	"\010pipefail"
 	"\006verify"
+	"\013braceexpand"
 ;
 #endif
 
Index: bin/sh/parser.c
===================================================================
--- bin/sh/parser.c
+++ bin/sh/parser.c
@@ -39,7 +39,9 @@
 #endif /* not lint */
 #include <sys/cdefs.h>
 #include <sys/param.h>
+#include <ctype.h>
 #include <pwd.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <stdio.h>
@@ -132,6 +134,7 @@
 static void setprompt(int);
 static int pgetc_linecont(void);
 static void getusername(char *, size_t);
+static bool expandbrace(FILE *, const char *);
 
 
 static void *
@@ -820,6 +823,174 @@
 	return (t);
 }
 
+static bool expandsequence(FILE *stream, const char prefix[static 1], const char *pattern) {
+	char format[] = "%0.*d%.*s";
+	int start, end, step, i;
+	const char *p, *close;
+	char *portal, *endptr;
+	const char *terminator = strchr(pattern, '\0');
+	int prefixlen = (int)(pattern - prefix - 1);
+	int size = prefixlen + 32;
+	int zeroes = 0;
+
+	/* Parse start value (letter or number) */
+	if (isalpha(pattern[0])) {
+		start = pattern[0];
+		p = pattern + 1;
+	} else if (isspace(pattern[0]))
+		/* strtol accepts space here, brace expansion doesn't */
+		return false;
+	else {
+		zeroes = strspn(pattern, "0");
+		start = strtol(pattern + zeroes, &endptr, 10);
+		if (pattern == endptr)
+			return false;
+		p = endptr;
+	}
+
+	/* Verify ".." separator */
+	if (*p++ != '.' || *p++ != '.')
+		return false;
+
+	/* Parse end value (must match type of start) */
+	if (isalpha(p[0])) {
+		if (!isalpha(pattern[0]))
+			return false;
+		end = *p++;
+		format[4] = 'c';
+	} else if (isspace(p[0]))
+		return false;
+	else {
+		int z = strspn(p, "0");
+
+		if (z > zeroes)
+			zeroes = z;
+		close = p + z;
+		end = strtol(close, &endptr, 10);
+		if (close == endptr)
+			return false;
+		p = endptr;
+	}
+
+	/* Parse optional step value */
+	if (*p == '}')
+		step = 1;
+	else if (*p++ == '.' && *p++ == '.') {
+		if (*p == '+' || *p == '-')
+			p++; /* Direction will be determined by testing start > end */
+		if (!isdigit(*p))
+			return false;
+		step = strtol(p, &endptr, 10);
+		if (*endptr != '}')
+			return false;
+		p = endptr;
+	} else
+		return false;
+	close = p;
+
+	/* Each of the generated terms will start from the same prefix */
+	if (!(portal = malloc(size)))
+		return false;
+	snprintf(portal, size, "%.*s", prefixlen, prefix);
+	size -= prefixlen;
+
+	/* Generate sequence */
+	i = start;
+	if (start > end)
+		step = -step;
+	goto first_iteration;
+	while (start > end ? i >= end : i <= end) {
+		if (isalpha(pattern[0]) && !isalpha(i))
+			break;
+		fputc(' ', stream);
+first_iteration:
+		/* Copy the generated term and the suffix */
+		snprintf(portal + prefixlen, size, format,
+			zeroes + 1, i, (int)(terminator - close), close + 1);
+
+		/* The string may be a brace expansion pattern too */
+		expandbrace(stream, portal);
+		i += step;
+	}
+	free(portal);
+
+	return true;
+}
+
+static bool expandbrace(FILE *stream, const char pattern[static 1]) {
+	const char *close, *separator, *last;
+	int prefixlen;
+	char *portal;
+	const char *open = pattern;
+	const char *end = strchr(pattern, '\0');
+	int size = end - pattern;
+
+	/* Unescaped braces and one of the separators are required */
+	if (open && open[0] != '{')
+		while ((open = strchr(open + 1, '{'))) {
+			if (open[-1] == '\\')
+				continue;
+			if (open[-1] != '$')
+				break;
+			/* '${' restarts the search for '{' from the closest '}' */
+			if (!(open = strchr(open + 1, '}')))
+				break;
+		}
+
+	/* When checking for sequence, don't go past the first closing brace */
+	if (open && (separator = strpbrk(open + 1, ".}")))
+		if (separator[0] == '.' && separator[1] == '.')
+			if (expandsequence(stream, pattern, open + 1))
+				return true;
+
+	/* If not a sequence, the comma is required */
+	if ((separator = open))
+		while ((separator = strchr(separator + 1, ',')))
+			if (separator[-1] != '\\')
+				break;
+
+	/* Only look for closing brace once the comma has been found */
+	if ((close = separator))
+		while ((close = strchr(close + 1, '}')))
+			if (close[-1] != '\\')
+				break;
+
+	/* Not a brace expansion pattern, treat literally */
+	if (!close || !(portal = malloc(size))) {
+		fputs(pattern, stream);
+		return false;
+	}
+
+	/* Each of the generated alternatives will start from the same prefix */
+	prefixlen = snprintf(portal, size, "%.*s",
+		(int)(open - pattern), pattern);
+	size -= prefixlen;
+
+	/* Generate alternatives */
+	last = open + 1;
+	goto first_iteration;
+	for (;;) {
+		fputc(' ', stream);
+first_iteration:
+		/* Copy the generated alternative and the suffix */
+		snprintf(portal + prefixlen, size, "%.*s%.*s",
+			(int)((separator ? separator : close) - last), last,
+			(int)(end - close), close + 1);
+
+		/* The string may be a brace expansion pattern too */
+		expandbrace(stream, portal);
+
+		/* Find the next alternative */
+		if (!separator)
+			break;
+		last = separator + 1;
+		separator = memchr(last, ',', close - separator - 1);
+	}
+	free(portal);
+    return true;
+}
+
+
 static int
 readtoken(void)
 {
@@ -863,6 +1034,23 @@
 			pushstring(ap->val, strlen(ap->val), ap);
 			goto top;
 		}
+		if (braceexpandflag && wordtext != NULL) {
+			FILE *memstream;
+			char *buf;
+			size_t len;
+			bool expanded;
+
+			if ((memstream = open_memstream(&buf, &len)) == NULL)
+				goto out;
+
+			expanded = expandbrace(memstream, wordtext);
+			fclose(memstream);
+
+			if (expanded) {
+				pushstring(buf, len, NULL);
+				goto top;
+			}
+		}
 	}
 out:
 	if (t != TNOT)
Index: bin/sh/sh.1
===================================================================
--- bin/sh/sh.1
+++ bin/sh/sh.1
@@ -364,6 +364,8 @@
 when sourcing files or loading profiles.
 .\" See also
 .\" .Xr mac_veriexec 4 . TODO Does not exist; write it.
+.It Li braceexpand
+Enable brace expansion.
 .El
 .Pp
 The