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Sat, 30 Jan 2021 11:00:26 -0800 (PST) MIME-Version: 1.0 References: <1b788ada-9c70-78e5-cc2c-1943000f2994@eastlink.ca> <20210128100858.GA578422@zira.vinc17.org> <20210128102816.GB578422@zira.vinc17.org> <560cef52-aee7-352a-2ba3-25826fe54136@eastlink.ca> <14ce37b2-35ca-6002-474a-7de5d6626a66@eastlink.ca> <05c3d2ba-6a00-9480-e2a8-685432e2442c@eastlink.ca> In-Reply-To: From: Bart Schaefer Date: Sat, 30 Jan 2021 11:00:15 -0800 Message-ID: Subject: Re: detect pipe To: Ray Andrews Cc: Zsh Users Content-Type: text/plain; charset="UTF-8" X-Seq: 26445 Archived-At: X-Loop: zsh-users@zsh.org Errors-To: zsh-users-owner@zsh.org Precedence: list Precedence: bulk Sender: zsh-users-request@zsh.org X-no-archive: yes List-Id: List-Help: List-Subscribe: List-Unsubscribe: List-Post: List-Owner: List-Archive: Archived-At: On Sat, Jan 30, 2021 at 6:27 AM Ray Andrews wrote: > > Cool stuff Bart. Would you please elaborate on 'Close stdin'? ubuntu% ls /dev/fd/0 /dev/fd/0 ubuntu% ls /dev/fd/0 <&- ls: cannot access '/dev/fd/0': No such file or directory File descriptor zero, the standard input, has been closed; it literally does not exist for "ls" (in this example). If it's closed, it's not possible to read from it: ubuntu% cat <&- cat: -: Bad file descriptor cat: closing standard input: Bad file descriptor Most commands will ignore a closed stdin and behave similarly to reading from /dev/null.