xref: /aosp_15_r20/external/musl/src/unistd/isatty.c (revision c9945492fdd68bbe62686c5b452b4dc1be3f8453)
1*c9945492SAndroid Build Coastguard Worker #include <unistd.h>
2*c9945492SAndroid Build Coastguard Worker #include <errno.h>
3*c9945492SAndroid Build Coastguard Worker #include <sys/ioctl.h>
4*c9945492SAndroid Build Coastguard Worker #include "syscall.h"
5*c9945492SAndroid Build Coastguard Worker 
isatty(int fd)6*c9945492SAndroid Build Coastguard Worker int isatty(int fd)
7*c9945492SAndroid Build Coastguard Worker {
8*c9945492SAndroid Build Coastguard Worker 	struct winsize wsz;
9*c9945492SAndroid Build Coastguard Worker 	unsigned long r = syscall(SYS_ioctl, fd, TIOCGWINSZ, &wsz);
10*c9945492SAndroid Build Coastguard Worker 	if (r == 0) return 1;
11*c9945492SAndroid Build Coastguard Worker 	if (errno != EBADF) errno = ENOTTY;
12*c9945492SAndroid Build Coastguard Worker 	return 0;
13*c9945492SAndroid Build Coastguard Worker }
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