1 files changed, 10 insertions, 0 deletions
diff --git a/run.c b/run.c
index 136e20a..2bef988 100644
--- a/run.c
+++ b/run.c
@@ -1983,6 +1983,13 @@ void backsub(char **pb_ptr, const char **sptr_ptr)	/* handle \\& variations */
 {						/* sptr[0] == '\\' */
 	char *pb = *pb_ptr;
 	const char *sptr = *sptr_ptr;
+	static bool first = true;
+	static bool do_posix = false;
+
+	if (first) {
+		first = false;
+		do_posix = (getenv("POSIXLY_CORRECT") != NULL);
+	}
 
 	if (sptr[1] == '\\') {
 		if (sptr[2] == '\\' && sptr[3] == '&') { /* \\\& -> \& */
@@ -1992,6 +1999,9 @@ void backsub(char **pb_ptr, const char **sptr_ptr)	/* handle \\& variations */
 		} else if (sptr[2] == '&') {	/* \\& -> \ + matched */
 			*pb++ = '\\';
 			sptr += 2;
+		} else if (do_posix) {		/* \\x -> \x */
+			sptr++;
+			*pb++ = *sptr++;
 		} else {			/* \\x -> \\x */
 			*pb++ = *sptr++;
 			*pb++ = *sptr++;