From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 25147 invoked by alias); 18 Nov 2014 16:39:39 -0000 Mailing-List: contact zsh-users-help@zsh.org; run by ezmlm Precedence: bulk X-No-Archive: yes List-Id: Zsh Users List List-Post: List-Help: X-Seq: 19402 Received: (qmail 10954 invoked from network); 18 Nov 2014 16:39:34 -0000 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on f.primenet.com.au X-Spam-Level: X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_HI, SPF_HELO_PASS autolearn=ham version=3.3.2 X-AuditID: cbfec7f4-b7f6c6d00000120b-bf-546b7642dd9f Date: Tue, 18 Nov 2014 16:39:29 +0000 From: Peter Stephenson To: Zsh-Users List Subject: Re: 'login' vs 'interactive' ? Message-id: <20141118163929.71afd221@pwslap01u.europe.root.pri> In-reply-to: References: Organization: Samsung Cambridge Solution Centre X-Mailer: Claws Mail 3.7.9 (GTK+ 2.22.0; i386-redhat-linux-gnu) MIME-version: 1.0 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFuphluLIzCtJLcpLzFFi42I5/e/4ZV2nsuwQg5tr9C12nFzJ6MDoserg B6YAxigum5TUnMyy1CJ9uwSujG+LN7EX9OlW9LZtZm9gXKLcxcjJISFgIvH91zomCFtM4sK9 9WxdjFwcQgJLGSUm793DDpIAcpgk1u8KBrFZBFQlvr18zwJiswkYSkzdNJsRxBYRUJO4/Gg5 WFxYQF1i7rN1YL28AvYSV87sBlvAKRAscWP5NhaImQESe1YsArP5BfQlrv79BHWEvcTMK2cY IXoFJX5MvgdWwyygJbF5WxMrhC0vsXnNW+YJjAKzkJTNQlI2C0nZAkbmVYyiqaXJBcVJ6bmG esWJucWleel6yfm5mxghIfhlB+PiY1aHGAU4GJV4eBs2ZoUIsSaWFVfmHmKU4GBWEuE91w0U 4k1JrKxKLcqPLyrNSS0+xMjEwSnVwDg36Q6XA1ul9eQHzg2zBI5bNy6NE1sXxbnzTYLouwVP dn85NVFVWOSDwGKPq8pFc5Q31i3c+Pu9foPAf6dbU/t8N06YYbYx+91y9osTGV70Z69m/imj IVX7r0sxvz3v/4++HNt9Vb2iEpulmxQ+d6wX5f82Qfvlhc+Tg6PXX/z49Ud/dOFE8TdKLMUZ iYZazEXFiQDlZnT3HwIAAA== On Tue, 18 Nov 2014 11:11:46 -0500 TJ Luoma wrote: > 1) Can someone explain the difference between 'login' and > 'interactive' in these two examples: > > if [[ -o login ]]; then > echo "I'm a login shell" > fi > > if [[ -o interactive ]]; then > echo "I'm interactive" > fi Overall, the differences are two-fold (i) how you got there (ii) what the consequences are. You might like to read zsh.sourceforge.net/Guide/zshguide02.html which I wrote some years ago but makes attempts in the right direction. How you got there --- what makeas a shell a login shell --- is described on page 108 of "From Bash to Z Shell". Basically, it's done by executive decision of whatever it is that's starting your shell. That's not very easy to summarise nowadays when there are so many ways of starting the shell. What makes a shell interactive is very roughly that the shell itself thought it had an environment that looked like a terminal and couldn't think of any reason why the user might not want it to use that terminal (e.g. being passed a script is such a reason). What the consequences are has got a lot to do with startup files, so I've appended the bit from the FAQ (this is pretty much the only use of being a login shell, apart from an explicit test like the one you've got above). However, the shell bases a number of internal decisions on whether or not it's interactive. These are intended to be common sense, e.g. if it's interactive you want the line editor and if it's not interactive you don't. Needless to say, it's not always that simple. > 2) is 'login' vs 'interactive' similar to "every square is a rectangle > but a rectangle is not necessarily a square"? > > As in "Every login shell is interactive, but an interactive shell is > not necessarily a login shell"? Not necessarily, in fact, because neither of the two points above is a subset of the other. For example, something managing the way your window system starts may decide to launch the shell that sets up the environment as a login shell, but without a terminal. > 3) Imagine an alternate universe where zsh _automatically_ reads > ~/.zshenv but NOT ~/.zshrc so you had to tell zsh to read ~/.zshrc as > part of ~/.zshenv. > > Would the answer be: > > if [[ -o login ]]; then > source .zshrc > fi > > or > > if [[ -o interactive ]]; then > source .zshrc > fi The second. This actually is well-defined and even documented. See below. > 4) Anything else I should understand about these two? Your counterfactual ~/.zshenv would also contain (being somewhat more, but not necessarily completely, pedantic about associated tests): if [[ -o login && -f ${ZDOTDIR:-$HOME}/.zlogin ]]; then source ${ZDOTDIR:-$HOME}/.zlogin fi and there's likewise pseudo-code for .zlogout (but nowhere to put it other than an EXIT trap). FAQ excerpt follows. 3.2: In which startup file do I put...? When zsh starts up, there are four files you can change which it will run under various circumstances: .zshenv, .zprofile, .zshrc and .zlogin. They are usually in your home directory, but the variable $ZDOTDIR may be set to alter that. Here are a few simple hints about how to use them. There are also files which the system administrator can set for all shells; you can avoid running all except /etc/zshenv by starting zsh with the -f option --- for this reason it is important for administrators to make sure /etc/zshenv is as brief as possible. The order in which the four files are searched (none of them _need_ to exist) is the one just given. However, .zprofile and .zlogin are only run when the shell is a login shell --- when you first login, of course, and whenever you start zsh with the -l option. All login shells are interactive. The order is the only difference between those; you should decide whether you need things set before or after .zshrc. These files are a good place to set environment variables (i.e. `export' commands), since they are passed on to all shells without you having to set them again, and also to check that your terminal is set up properly (except that if you want to change settings for terminal emulator windows like xterm you will need to put those in .zshrc, since usually you do not get a login shell here). The only file you can alter which is started with every zsh (unless you use the -f option) is .zshenv, so this is a good place to put things you want even if the shell is non-interactive: options for changing the syntax, like EXTENDED_GLOB, any changes to set with `limit', any more variables you want to make sure are set as for example $fpath to find functions. You almost certainly do not want .zshenv to produce any output. Some people prefer not to use .zshenv for setting options, as this affects scripts; but making zsh scripts portable usually requires special handling anyway. Finally, .zshrc is run for every interactive shell; that includes login shells, but also any other time you start up a shell, such as simply by typing `zsh' or opening a new terminal emulator window. This file is the place to change the editing behaviour via options or `bindkey', control how your history is saved, set aliases unless you want to use them in scripts too, and for any other clutter which can't be exported but you only use when interacting directly with the shell. You probably don't want .zshrc to produce output, either, since there are occasions when this can be a problem, such as when using `rsh' from another host. See 3.21 for what to put in .zshrc to save your history. pws