musl - musl - an implementation of the standard library for Linux-based systems

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;

}

diff --git a/src/unistd/ttyname_r.c b/src/unistd/ttyname_r.c
index cb364c29..82acb75e 100644
--- a/src/unistd/ttyname_r.c
+++ b/src/unistd/ttyname_r.c

@@ -9,7 +9,7 @@ int ttyname_r(int fd, char *name, size_t size)

char procname[sizeof "/proc/self/fd/" + 3*sizeof(int) + 2];

ssize_t l;

- if (!isatty(fd)) return ENOTTY;

+ if (!isatty(fd)) return errno;

__procfdname(procname, fd);

l = readlink(procname, name, size);