tty(1)tty(1)NAMEtty - Returns pathname of terminal device
SYNOPSIStty [-s]
The tty command writes the full pathname of your terminal device to
standard output. The tty command may also be used to determine if
standard input is a terminal.
STANDARDS
Interfaces documented on this reference page conform to industry stan‐
dards as follows:
tty: XCU5.0
Refer to the standards(5) reference page for more information about
industry standards and associated tags.
OPTIONS
Suppresses reporting the pathname.
The XCU specification states that -s option is obsolete and recommends
the portable applications use test -t 0 instead of tty-s.
OPERANDS
None
DESCRIPTION
The command tty-s evaluates as TRUE if standard input is a display and
FALSE if it is not.
[Tru64 UNIX] The file /dev/tty is a special file always refers to your
controlling terminal, although it also may have another name like
/dev/console or /dev/tty2. To avoid writing undesirable output to an
output file--for example, to write a prompt in a shell script to the
screen, while writing the response to the prompt to an output file--re‐
direct standard output to /dev/tty.
NOTES
While the -s option is useful if only the exit code is wanted, it does
not rely on any ability to form a valid pathname. For a portable appli‐
cation you should use the command test -t 0.
EXIT STATUS
The following exit values are returned: Successful completion. Stan‐
dard input is not a display. [Tru64 UNIX] Invalid options specified.
[Tru64 UNIX] An error occurred.
DIAGNOSTICS
[Tru64 UNIX] Your standard input is not a display and you did not
specify the -s option.
EXAMPLES
To display full pathname of your terminal device, enter: tty To test
whether or not the standard input is a terminal device, create a shell
script containing the following: if tty-s then echo 'Output is a
display' else echo 'Output is not a display' fi
If the standard input is a terminal device, this displays the
Output is a display message. If the standard input is not a ter‐
minal device, it displays the Output is not a display message.
ENVIRONMENT VARIABLES
The following environment variables affect the execution of tty: Pro‐
vides a default value for the internationalization variables that are
unset or null. If LANG is unset or null, the corresponding value from
the default locale is used. If any of the internationalization vari‐
ables contain an invalid setting, the utility behaves as if none of the
variables had been defined. If set to a non-empty string value, over‐
rides the values of all the other internationalization variables.
Determines the locale for the interpretation of sequences of bytes of
text data as characters (for example, single-byte as opposed to multi‐
byte characters in arguments). Determines the locale for the format
and contents of diagnostic messages written to standard error. Deter‐
mines the location of message catalogues for the processing of LC_MES‐
SAGES.
FILES
Pseudodevice representing the user's controlling terminal.
SEE ALSO
Commands: stty(1), test(1)
Routines: ttyname(3)
Files: tty(7)
Standards: standards(5)tty(1)
