Add a "fork" of musl as //fusl.

fusl/src/stdio/fgets.c

Index: fusl/src/stdio/fgets.c
diff --git a/fusl/src/stdio/fgets.c b/fusl/src/stdio/fgets.c
new file mode 100644
index 0000000000000000000000000000000000000000..d3f9819e82eec3a5707805d5ae5b661a78adec30
--- /dev/null
+++ b/fusl/src/stdio/fgets.c
@@ -0,0 +1,46 @@
+#include "stdio_impl.h"
+#include <string.h>
+
+#define MIN(a,b) ((a)<(b) ? (a) : (b))
+
+char *fgets(char *restrict s, int n, FILE *restrict f)
+{
+	char *p = s;
+	unsigned char *z;
+	size_t k;
+	int c;
+
+	FLOCK(f);
+
+	if (n--<=1) {
+		f->mode |= f->mode-1;
+		FUNLOCK(f);
+		if (n) return 0;
+		*s = 0;
+		return s;
+	}
+
+	while (n) {
+		z = memchr(f->rpos, '\n', f->rend - f->rpos);
+		k = z ? z - f->rpos + 1 : f->rend - f->rpos;
+		k = MIN(k, n);
+		memcpy(p, f->rpos, k);
+		f->rpos += k;
+		p += k;
+		n -= k;
+		if (z || !n) break;
+		if ((c = getc_unlocked(f)) < 0) {
+			if (p==s || !feof(f)) s = 0;
+			break;
+		}
+		n--;
+		if ((*p++ = c) == '\n') break;
+	}
+	if (s) *p = 0;
+
+	FUNLOCK(f);
+
+	return s;
+}
+
+weak_alias(fgets, fgets_unlocked);