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wall (an abbreviation of ''write to all'') is a Unix command-line utility that displays the contents of a file or standard input to all logged-in users. It is typically used by root to send out shutting down message to all users just before poweroff. == Invocation == wall reads the message from standard input by default when the filename is omitted, that can be done by piping it with the echo command: alice@sleipnir:~$ # `tty` to show the current terminal name alice@sleipnir:~$ tty /dev/pts/7 alice@sleipnir:~$ echo Remember to brush your teeth! | wall The message may also be typed in much the same way cat is used; invoking wall by typing wall and pressing followed by a message, pressing and : alice@sleipnir:~$ wall Remember to brush your teeth! ^D Using a here-string: alice@sleipnir:~$ wall <<< 'Remember to brush your teeth!' Reading from a file is also supported: alice@sleipnir:~$ cat .important_announcement Remember to brush your teeth! alice@sleipnir:~$ wall .important_announcement # same as `wall !$` All the commands above should display the following output on terminals that users allow write access to (see mesg(1)): Broadcast Message from alice@sleipnir (/dev/pts/7) at 16:15 ... Remember to brush your teeth! 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Wall (Unix)」の詳細全文を読む スポンサード リンク
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