X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Funistd%2Fisatty.c;h=75a9c186a941896f90dd0985fe4b1fe86d351f54;hb=a60b9e06861e56c0810bae0249b421e1758d281a;hp=c8badaf55edd7d6c4e692e5d238e093848cc7290;hpb=2de85a985654d2c944931267645d9a0686242dfe;p=musl

diff --git a/src/unistd/isatty.c b/src/unistd/isatty.c
index c8badaf5..75a9c186 100644
--- a/src/unistd/isatty.c
+++ b/src/unistd/isatty.c
@@ -1,9 +1,13 @@
 #include <unistd.h>
+#include <errno.h>
 #include <sys/ioctl.h>
 #include "syscall.h"
 
 int isatty(int fd)
 {
 	struct winsize wsz;
-	return !__syscall(SYS_ioctl, fd, TIOCGWINSZ, &wsz);
+	unsigned long r = syscall(SYS_ioctl, fd, TIOCGWINSZ, &wsz);
+	if (r == 0) return 1;
+	if (errno != EBADF) errno = ENOTTY;
+	return 0;
 }