isatty (3)

Test whether a file descriptor refers to a terminal

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  4. isatty: Test whether a file descriptor refers to a terminal
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  4. isatty: Test whether a file descriptor refers to a terminal

SYNOPSIS

#include <unistd.h>

int isatty(int fd);

DESCRIPTION

The isatty() function tests whether fd is an open file descriptor referring to a terminal.

RETURN VALUE

isatty() returns 1 if fd is an open file descriptor referring to a terminal; otherwise 0 is returned, and errno is set to indicate the error.

ERRORS

EBADF

fd is not a valid file descriptor.

EINVAL

fd refers to a file other than a terminal. POSIX.1-2001 specifies the error ENOTTY for this case.

ATTRIBUTES

Multithreading (see pthreads(7))

The isatty() function is thread-safe.

CONFORMING TO

SVr4, 4.3BSD, POSIX.1-2001.

RELATED TO isatty…

fstat(2), ttyname(3)

COLOPHON

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