Markdown Mode for Emacs version 2.3 was released on August 31, 2017.\nThis is a major new stable release and all users are encouraged to\nupgrade. The many new features and bug fixes included are described\nbelow. See the Git repository or the commit-specific links below\nfor a detailed history of changes. Thanks to everyone who submitted\nbug reports, feature suggestions, and especially patches.
\n\nThe major new features are the following (but see the release notes\nbelow for complete details):
\n\n![\"Guide](\"https://jblevins.org/projects/markdown-mode/guide-v2.3.png\")
\nThe Guide to Markdown Mode for Emacs is now also available\nat Leanpub to supplement the existing documentation. It contains\nin-depth discussions of advanced movement and editing commands,\nconfiguration examples, tips and tricks, and a survey of other\npackages that work with Markdown Mode.
Breaking changes:
\n\nmarkdown-mode now requires Emacs 24.3 or later.markdown-insert-link, bound to C-c C-l.\nAs such, the previous separate link insertion keybindings have\nbeen removed: C-c C-a l, C-c C-a L,\nC-c C-a r, and C-c C-a u.markdown-insert-image, bound to C-c C-i.\nAs such, the previous separate image insertion keybindings have\nbeen removed: C-c C-i i and C-c C-i I.markdown-jump, previously bound to C-c C-l, has\nbeen moved to C-c C-d and rebranded as\nmarkdown-do, which attempts to do something sensible with\nthe object at the point.markdown-link-link to markdown-link-url\nfor clarity.markdown-blockquote-face is now applied to the entire\nblockquote, including the leading >, so it can be used to\napply a background if desired.markdown-regex-header, groups 4 and 6 now include\nwhitespace surrounding hash marks in atx headings.~~strikethrough~~ is now supported in\nmarkdown-mode in addition to gfm-mode.markdown-hr-face.\nPreviously, markdown-header-delimiter-face was used.markdown-fill-forward-paragraph-function to\nmarkdown-fill-forward-paragraph.markdown-footnote-face to markdown-footnote-marker-face.markdown-insert-inline-link-dwim and\nmarkdown-insert-reference-link-dwim have been combined and\nreplaced with markdown-insert-link.markdown-exdent-region and markdown-exdent-or-delete\nare now named markdown-outdent-region and\nmarkdown-outdent-or-delete, respectively.markdown-insert-image (for inline images) has\nbeen renamed markdown-insert-inline-image and it now takes\nthree arguments (previously one optional argument).\nmarkdown-insert-reference-image now takes four arguments\n(previously none).New features:
\n\nmarkdown-hide-markup,\nwhich determines whether to hide or otherwise beautify\nMarkdown markup. For example, for inline links the brackets,\nURL, and title will be hidden and only the (clickable) link\ntext will remain. The URL can be seen by hovering with the\nmouse pointer and edited by deleting one of the invisible\nbrackets or parentheses. This can be toggled interactively\nusing C-c C-x C-m (markdown-toggle-markup-hiding).\nThis setting supersedes URL hiding (below). (GH–130)markdown-list-item-bullets.\n(GH–130)markdown-blockquote-display-char,\nmarkdown-hr-display-char, and\nmarkdown-definition-display-char.markdown-hide-urls. URLs will appear as\n[link](∞) instead of\n[link](http://perhaps.a/very/long/url/). To change the\nplaceholder character used, set markdown-url-compose-char.\nThis feature can be toggled using C-c C-x C-l\n(markdown-toggle-url-hiding). If full markup hiding (above)\nis enabled, then URL hiding has no additional effect.markdown-fontify-code-blocks-natively, which determines\nwhether to fontify code in code blocks using the native major\nmode. This only works for fenced code blocks where the\nlanguage is specified where we can automatically determine the\nappropriate mode to use. The language to mode mapping may be\ncustomized by setting the variable markdown-code-lang-modes.\n(GH–123, GH–185)edit-indirect\npackage is installed, C-c ’ (markdown-edit-code-block)\ncan be used to edit a code block in an indirect buffer in the native\nmajor mode. Press C-c C-c to commit changes and return\nor C-c C-k to cancel.markdown-toggle-fontify-code-blocks-natively).markdown-forward-page (C-x ]),\nmarkdown-backward-page (C-x [),\nmarkdown-mark-page (C-x C-p), and\nmarkdown-narrow-to-page (C-x n p). (GH–191)markdown-mark-subtree (C-c C-M-h) and\nmarkdown-narrow-to-subtree (C-x n s).\n(GH–191)markdown-backward-paragraph) and\nM-} (markdown-forward-paragraph). To mark a\nparagraph, use M-h (markdown-mark-paragraph).\nThese move at a more granular level than the block movement\ncommands. (GH–191)subtree as a possible value for\nmarkdown-reference-location and\nmarkdown-footnote-location.H~2~0)\nand superscripts (e.g., 334^10^). Thanks to Syohei Yoshida\nfor a patch on which this is based. (GH–134)<<(file), <<[title](file), <<[file], and <<{file}.markdown-insert-link. (GH–199)markdown-do, which is a\nreplacement for C-c C-l, markdown-jump. In\naddition to jumping between reference/footnote labels and\ndefinitions, it also toggles GFM checkboxes.markdown-spaces-after-code-fence to\ncontrol the number of spaces inserted after a code fence (```).\nThanks to Philipp Stephani for a patch.markdown-gfm-uppercase-checkbox which,\nwhen non-nil, uses [X] to complete task list items instead of\n[x]. Thanks to Paul Rankin for a patch. (GH–236)C-c C-s) and toggles\n(C-c C-x). These may be disabled if desired by setting\nmarkdown-enable-prefix-prompts to nil.Improvements:
\n\n:package-version tags.-p shouldn’t modify match data.{forward,backward,mark}-paragraph bindings.markdown-toggle-inline-images now displays the status in the\nminibuffer.markdown-gfm-recognized-languages.fill-region now leaves code blocks unmodified.\n(GH–192)comment-use-syntax. (GH–213)electric-quote-inhibit-functions for inhibiting\nelectric quoting in code spans and blocks. Thanks to Philipp\nStephani for patches to both Emacs and Markdown Mode.\n(GH–220)Bug fixes:
\n\nmarkdown-font-lock-extend-region-function. Thanks to\nPhilipp Stephani for a patch. (GH–221)![\"Dot](\"https://jblevins.org/log/dot-grid-paper.png\")
\nI use GoodNotes (iOS, macOS) for taking hand-written notes\non my iPad. It has a variety of paper templates built-in—ruled,\ngrid, Cornell, and so on—but I wanted to give dot grid paper a try.\nRather than go out and buy a ream of it, I created several PDFs\nfor 1/4" (quarter inch) dot grid paper that I can load into GoodNotes\nas templates (U.S. Letter size).
\n\nThe result is on GitHub. The repository also contains the\nPython script and LaTeX package (.sty file) I used to generate them.\nThe script generates individual LaTeX files (which in turn use the\nLaTeX package) for each of several specifications:
\n\nSee the dot-grid-paper repository on GitHub for more details.
\n" }, { "title": "Using Custom CSS in Markdown Mode", "date_published": "2017-08-11T23:11:00Z", "date_modified": "2017-08-11T23:11:00Z", "summary": "How to link to an external CSS stylesheet or include an inline style block in HTML output from Markdown Mode.", "id": "tag:jblevins.org,2017:/log/custom-css", "url": "https://jblevins.org/log/custom-css", "author" : { "name" : "Jason Blevins", "url": "https://jblevins.org/" }, "content_html": "The default stylesheet for HTML in most browsers is rather\nunattractive, so you may want to use a custom stylesheet by either\nlinking to an external stylesheet or including a <style> block in\nthe exported HTML itself.
![\"Custom](\"https://jblevins.org/log/custom-css.png\")
\nThe easiest way to customize the style of previewed and exported HTML\noutput is to link to an existing CSS stylesheet. Markdown Mode has a\ncustomizable variable markdown-css-paths, which is a list of\nstylesheets to link to. For each path or URL in markdown-css-paths,\na line like the following will be included in the HTML output:
<link rel=\"stylesheet\" type=\"text/css\" media=\"all\" href=\"URL\" />\nThe most obvious way to use this is to link to an existing stylesheet.\nNoting that the variable is a list, one can specify a single CSS path\non the local filesystem like so:
\n\n\n(setq markdown-css-paths '(\"/path/to/custom.css\"))\nOn the other hand, to use an existing URL use the following form:
\n\n\n(setq markdown-css-paths '(\"http://mydomain.com/style.css\"))\nAs another example, the Marked 2 previewer contains several\nbuilt-in stylesheets that users can choose between. Conveniently,\nthese stylesheets are stored on the filesystem as CSS files inside the\napplication package and you can link to them locally. To use the\n“Lopash” style when previewing from markdown-mode, you can set the\nmarkdown-css-paths list as follows:
(setq markdown-css-paths\n '(\"/Applications/Marked 2.app/Contents/Resources/Lopash.css\"))\nIf you don’t have a stylesheet already, there are many popular\nMarkdown stylesheets available online. For example, here are three\nsuch repositories on GitHub:
\n\nAs an alternative (or in addition to) linking to an external\nstylesheet, you can also include inline style information in output\nfiles by using the markdown-xhtml-header-content variable. This\nvariable specifies a string to add to the <head> block of the\nresulting HTML output.
For example, to remove the underline from links, but underline links\nwhen hovering, you can add the following <style> block to\nmarkdown-xhtml-header-content:
(setq markdown-xhtml-header-content\n \"<style type='text/css'>\na { text-decoration: none; }\na:hover { text-decoration: underline; }\n</style>\")\nMarkdown Mode for Emacs includes support for imenu, an\ninterface for quickly navigating to different sections within a\nbuffer. To try imenu with Markdown Mode, simply run M-x\nimenu-add-menubar-index. An “Index” menu will appear in the menubar.\nClicking a heading moves the point to that heading. Alternatively,\nwhen invoking M-x imenu using the keyboard Emacs will present you\nwith a list of headings in the minibuffer.
![\"imenu](\"https://jblevins.org/log/markdown-imenu-index.png\" "\\"Emacs")
\nimenu Index in Markdown ModeMarkdown Mode adds a “.” to the top of each sub-menu. Clicking this\ndot takes you to the parent section. Otherwise, there is no way to\njump directly to headings that are not “leaf nodes.”
\n\nTo automatically load imenu when markdown-mode is loaded, you can\nadd the following to your .emacs or init.el file:
(add-hook 'markdown-mode-hook 'imenu-add-menubar-index)\n(setq imenu-auto-rescan t)\nThe first line asks Emacs to run the imenu-add-menubar-index\nfunction each time markdown-mode is loaded. The second line asks\nimenu to keep the index up to date when files are modified, as\nsections may be added or removed.
Another useful imenu-based tool is imenu-list, a third-party\npackage which shows the current buffer’s imenu entries in a popup\nbuffer. You can install it from MELPA. I use use-package\nfor loading packages in my init file, so I configure it like this:
(use-package imenu-list\n :ensure t\n :bind ((\"C-'\" . imenu-list-smart-toggle))\n :config\n (setq imenu-list-focus-after-activation t\n imenu-list-auto-resize nil))\nThen, when pressing C-‘, a window appears on the right side\nshowing the heading hierarchy in the *Ilist* buffer. Pressing\nC-’ again hides the window.
![\"imenu-list](\"https://jblevins.org/log/markdown-imenu-list.png\" "\\"Emacs")
\nimenu-list with Markdown ModeOf course, there are several keybindings in the *Ilist* buffer for\nnavigating between sections:
imenu-list-minor-modeUnlike the imenu Index menu, the *Ilist* buffer is updated\nautomatically when Emacs is idle.
![\"Markdown](\"https://jblevins.org/log/blink-shell-emacs-markdown.png\" "\\"Blink")
\nBlink Shell is a unique and powerful shell app for iOS for connecting to remote hosts. Although it is perhaps not quite as polished as Prompt, my other favorite iOS SSH client, it has several features that Prompt does not.
\n\nWhen you first start Blink, there are no buttons or menus, as one expects from an iOS app. Instead, you are greeted with a cryptic blink> prompt in a black terminal with tiny white text.
This might be a bit disconcerting, but after a brief moment of panic, you will probably start to experiment with some commands. If you type an invalid command, Blink will inform you that you can type “help” to see a list of commands:
\n\nBlink: v7.0.1. Jul 11 2017\n\nAvailable commands:\n mosh: mosh client.\n ssh: ssh client.\n ssh-copy-id: Copy an identity to the server.\n config: Configure Blink. Add keys, hosts, themes, etc...\n help: Prints this.\n exit: Close this shell.\n\nAvailable gestures and keyboard shortcuts:\n two fingers tap or cmd+t: New shell.\n two fingers swipe down or cmd+w: Close shell.\n one finger swipe left/right or cmd+shift+[/]: Switch between shells.\n cmd+alt+N: Switch to shell number N.\n cmd+o: Switch to other screen (Airplay mode).\n cmd+shift+o: Move current shell to other screen (Airplay mode).\n cmd+,: Open config.\n pinch: Change font size.\nIf you have a Smart or Bluetooth keyboard attached—and you probably should to get the most out of Blink—then instead of typing a command you might try holding ⌘ to see a list of keyboard shortcuts.
\n\n![\"Blink](\"https://jblevins.org/log/blink-shell-keyboard-shortcuts.png\" "\\"Blink")
\nYou can see that pressing ⌘, is an alternative to typing config to enter the app settings. Note that this is the same keyboard shortcut for opening the preferences window in most macOS applications. You can also do normal shell things like Control+L to clear, Control+D to log out, and so on.
Blink works with both SSH and Mosh, but before connecting to a remote host you should first import your SSH login keys and set the default username for SSH connections.
\n\n![\"Configuring](\"https://jblevins.org/log/blink-shell-new-host.png\" "\\"Blink")
\nYou can issue the ssh command with the usual flags, such as ssh -l <username> <hostname>, but you’ll want to configure frequently-accessed hosts for convenience. Each host is given an alias, say <host> instead of <hostname>, so that once configured you can simply type ssh <host> or mosh <host> to connect with the pre-configured hostname, username, port, etc.
![\"SSH](\"https://jblevins.org/log/blink-shell-host-alias.png\" "\\"Blink")
\nFor basic SSH access to a host, you’ll need provide the following:
\n\nssh <name>) and it is case sensitive.Most readers probably use SSH already but may not have heard of Mosh, which is much newer. Mosh is designed to provide robust remote connections with roaming when your IP changes (e.g., switching from WiFi to cellular) and intermittent connectivity. Mosh piggy-backs on top of SSH, so if you already have remote SSH access you only need to install a user-level mosh-server binary to enable Mosh access.
If you have installed Mosh on the remote host, then you may also need to provide the following:
\n\nmosh-server binary (e.g., /usr/local/bin/mosh-server).1screen -d -R or tmux attach -t default).If you use Homebrew on macOS, installing Mosh is as simple as this:
\n\nbrew install mobile-shell\nOne of Blink’s most powerful features is the ability to customize the keyboard modifier keys. In fact, the reason I found Blink to begin with is it’s ability to use Caps Lock as a Control key (although there is an important caveat, discussed below).
\n\n![\"Customizable](\"https://jblevins.org/log/blink-shell-modifier-keys.png\" "\\"Blink")
\nIf you set Caps Lock to be a Control key, there is a very important caveat: Caps Lock may be in an unexpected state when you leave and re-enter blink. This is due to the limitations of iOS development. There is a GitHub issue devoted to this problem if you’d like to read more about the technical details.
\n\nTo summarize the issue, you can think in terms of two distinct Caps Lock states: one global in scope and one local. There is the iOS system-wide Caps Lock state and then the local state within the Blink app. If you are using Caps Lock as the control key, each time you press Caps Lock the system state is toggled but the Blink Caps Lock state remains off. The issue is that when you leave the Blink app, other apps honor the system state, which could be either on or off depending on whether you’ve pressed Caps Lock an even or odd number of times during your Blink session.
\n\nIf you have an Apple wireless keyboard with a Caps Lock light, the light follows the system state every time you use Caps Lock in Blink, so this can at least help you track the state. Overall, I’ve found that the annoyance of this issue is small in comparison to the convenience of using Caps Lock as Control in Emacs and for other shell commands.
\n\nAnother caveat is the small delay between when Caps Lock is pressed and when it is registered. When I quickly type control sequences as fast as I typically do—expecting no delay—the Control key part is not recognized. For example, to send ^C you’ll need to press Caps Lock and hold it for a fraction of a second longer than you typically might before pressing C. I don’t mean to overstate this issue, but I find that I do have to be more deliberate about entering control sequences.
There is a Blink Shell Theme Gallery with a huge selection of themes which you can access in Settings > Appearance > Add a new theme.
\n\n![\"Appearance](\"https://jblevins.org/log/blink-shell-themes.png\" "\\"Blink")
\nIn the screenshot, I’m enjoying the Fira Code font—the same font I use in Emacs, yes, a monospaced font with programming ligatures—with the Arthur theme for Blink.
\n\n\nThe keyboard shortcuts are also customizable. This includes the keys for switching to the previous and next shells, creating a new shell, closing a shell, and configuring Blink.
\n\nYou can purchase the Blink Shell app on the App Store. Blink is also open source, so you can take a look at the source code on GitHub.2
\n\nThis is the “Server” setting, which I found to be confusing at first. This field is not asking for a hostname (again), it is provided in case your mosh-server binary is not in your default PATH. ↩
If you’re looking at the source, you probably also want to see Nicolas Holzschuch’s branch, where he has added several common Unix commands for file management (ls, cp, rm, mkdir, etc.), text processing (cat, grep, wc), file transfer (curl, scp, sftp), and so on. ↩
Ten years ago, I added an Atom feed to this website. Before\nthat, there was an RSS feed—version 1—and for a while I had an RSS 2\nfeed. But in more recent years I disabled RSS and have used the Atom\nfeed exclusively.
\n\nThe reality for Atom is that, not only is it difficult to write valid\nXML by hand, but people also have trouble writing programs to generate\nvalid XML. Once a feed is available, it needs to be parsed. Even\nparsing valid Atom feeds is no simple task, but the implementation\nchallenges mean that there are also a bunch of broken Atom feeds in\nthe wild that feed reader writers have to deal with.
\n\nEnter JSON Feed, written by two individuals with a lot of\ncollective feed-processing experience, with the stated goal of being\n“simpler to read and write” and “less prone to bugs.” It has been\nadopted widely already, both by publishers and feed readers.
\n\nThis is all a long way of announcing that there is now\na JSON Feed for this site and you can validate it here.
\n" }, { "title": "File Local Variables in Emacs and Markdown Mode", "date_published": "2017-08-02T19:48:00Z", "date_modified": "2017-08-02T19:48:00Z", "summary": "How to use file local variables in Emacs generally, and specifically in Markdown Mode.", "id": "tag:jblevins.org,2017:/log/file-local-variables", "url": "https://jblevins.org/log/file-local-variables", "author" : { "name" : "Jason Blevins", "url": "https://jblevins.org/" }, "content_html": "Emacs allows one to specify values for variables inside files\nthemselves. For example, you can specify which mode Emacs should\nuse to edit a particular file by setting a special mode variable.\nYou can specify such file local variables at either the beginning or\nend of a file.
Perhaps you have seen lines like the following at the beginning of\nscripts. This particular line tells Emacs that you’d like to open\nthis file using cperl-mode:
#!/usr/bin/perl -*- mode: cperl -*-\nThe mode variable is special; it’s not an actual variable name in\nEmacs. Another special variable is coding, which specifies the\ncharacter coding system for this file (e.g., utf-8 or latin-1). A\nthird special variable is eval, which specifies a Lisp expression to\nevaluate. Multiple eval declarations can be given in the same file.
Among the special variables, mode is the most special of all and so\nthe mode: declaration can even be omitted:
#!/usr/bin/perl -*-cperl-*-\nFile variable definitions should appear in a comment, and the comment\nsyntax used by Markdown Mode is the same as for HTML comments:\n<!-- comment -->. So, to specify a local variable at the beginning\nof a file you could add the following to the first line (which would\nresult in Emacs loading the file in gfm-mode instead of, say,\nmarkdown-mode):
<!-- -*- mode: gfm -*- -->\nTo specify multiple variables, separate them by semicolons:
\n\n\n<!-- -*- mode: markdown; coding: utf-8 -*- -->\nAlternatively, you can insert a local variable block at the end of a\nfile. Such a block opens with a Local Variables: declaration and\ncloses with End:, like so:
<!-- Local Variables: -->\n<!-- markdown-enable-math: t -->\n<!-- End: -->\nIt’s not necessary that each line is a self-contained comment, so the\nfollowing also works and it is a personal preference which form you\nuse:
\n\n\n<!--\nLocal Variables:\nmarkdown-enable-math: t\nEnd:\n-->\nOne useful scenario for using file local variables with Markdown files\ninclude toggling special modes, like setting markdown-enable-math in\nthe previous example. If you mostly have math mode disabled (so that\n$ is not a special character), but sometimes want to enable it,\nusing a file-local variable as above is a great way to handle this\ncase.
Other example uses are setting the fill-column in a particular file,\nor declaring that spaces should be used for indentation instead of\ntabs:
<!--\nLocal Variables:\nfill-column: 70\nindent-tabs-mode: nil\nEnd:\n-->\nMarkdown Mode for Emacs version 2.2 was released on May 26,\n2017. This is a major new stable release and all users are\nencouraged to upgrade. The many new features and bug fixes included\nare described below. See the Git repository or the\ncommit-specific links below for a detailed history of changes. Thanks\nto everyone who submitted bug reports, feature suggestions, and\nespecially patches.
\n\n![\"Guide](\"https://jblevins.org/projects/markdown-mode/guide-v2.2.png\")
\nAdditionally, to celebrate Markdown Mode’s 10th birthday I am writing\na Guide to Markdown Mode for Emacs. This ebook will\nsupplement the existing documentation with in-depth discussion of\nadvanced movement and editing commands, configuration examples, tips\nand tricks, and a survey of other packages that work with Markdown\nMode. It will be published at Leanpub and possibly available\nthrough other channels. Please visit the book homepage to\nsign up to be notified when it is ready and to help determine the\nprice.
toggle menu style for macOS compatibility.auto-mode-alist.markdown-split-window-direction.markdown-jump (for moving between reference link/footnote\n markers and their definitions), it has been changed to C-c\n C-l (think “leap” or “loop” instead of jump). It’s also close\n to C-c C-o (used for opening links).<kbd> tags with C-c C-s k or\n markdown-insert-kbd.markdown-insert-header-dwim is invoked (C-c C-t h).markdown-cycle issue with heading-like strings in code blocks.\n Thanks to Syohei Yoshida.adaptive-fill-regexp so that fill-paragraph works for\n list items. Thanks to Syohei Yoshida for the patch.fill-paragraph. Thanks to Syohei Yoshida.fill-paragraph now respects paragraph boundaries within\n blockquotes.fill-paragraph from filling lines in code blocks.RET is pressed.\n markdown-indent-on-enter now has three settingsmarkdown-up-heading.markdown-header-scaling.font-lock-mode being nil.markdown-match-propertized-text to\n avoid possible infinite loop in font-lock. Thanks to Vitalie Spinu.<!-- > comment --> were not\n correctly identified.markdown-header-face inherit from nil error, e.g., when\n exporting HTML from an Org mode file containing a Markdown source\n block. Thanks to Moogen Tian for a patch.font-lock-refresh-defaults if font-lock-mode is\n non-nil to prevent it from being turned on when disabled by user.\n Thanks to Tom May for the patch.markdown-nested-imenu-heading-index as a customizable\n option. It may be disabled to instead generate a flat imenu index.\n A flat index may be more useful for keyboard navigation and\n auto-completion, while a nested index is probably more useful for\n menus and for use with packages such as imenu-list.markdown-toggle-inline-images\n and C-c C-i C-t. Thanks to Syohei Yoshida.markdown-follow-link-at-point) so that if a link is a complete\n URL, it will open in a browser. Otherwise, open it with find-file\n after stripping anchors and/or query strings.markdown-toggle-gfm-checkbox).markdown-enable-wiki-links. This may be set in a file local\n variable. Also added function markdown-toggle-wiki-links and a\n menu item.markdown-wiki-link-fontify-missing to control this behavior.markdown-wiki-link-search-subdirectories to enable searching\n for wiki link files in subdirectories.markdown-enable-math has been made obsolete and\n renamed to markdown-toggle-math. When called without an argument,\n the result is to toggle this extension rather than enable it. This\n is motivated by the behavior of minor mode functions.markdown-cleanup-list-numbers.\n Thanks to Danny McClanahan.point-max. Thanks to Syohei\n Yoshida.markdown-find-previous-prop. Thanks to\n Vitalie Spinu.Apple’s Swift programming language is most widely used for iOS and macOS development in Xcode, however, it can also be used in a manner more like a traditional Unix shell script or even compiled into an executable using the command line. Below, I give some examples of these alternative uses.
\n\nFor scripting, like other shell scripts, the first line of your script’s .swift file should be a “shebang”, which points to the swift executable. Following that, you can write Swift code as usual:
#!/usr/bin/swift\n\nfunc fibonacci(_ n: Int) -> Int {\n if n <= 2 {\n return 1\n } else {\n return fibonacci(n - 1) + fibonacci(n - 2)\n }\n}\n\nprint(fibonacci(10))\nYou can make the script executable and run it as you would any other shell script:
\n\n% chmod +x fibonacci.swift\n% ./fibonacci.swift\n55\nPrinting the 10th integer in the Fibonacci sequence is hard coded above, but what if you want to print other values? We can modify the script to take a single command line argument, the index of the Fibonacci number you want to print. Replace the last line above with the following:
\n\nlet arg = CommandLine.arguments[1] // Store first argument.\nif let n = Int(arg) { // If it converts to Int,\n print(fibonacci(n)) // print fibonacci(n).\n} else { // Otherwise,\n print("Usage: fibonacci <n>") // print usage and exit.\n}\nThen invoke the script as follows:
\n\n% ./fibonacci.swift 36\n14930352\n% ./fibonacci.swift junk\nUsage: fibonacci <n>\nAs with modern scripting languages such as Python and Ruby, you can also run Swift interactively (with Xcode 6.1 and later). The interactive command-line interface is called the Swift Read Eval Print Loop (REPL):
\n\n% swift\nWelcome to Apple Swift version 3.1 (swiftlang-802.0.48 clang-802.0.48). Type :help for assistance.\n 1> 1 + 2\n$R0: Int = 3\n 2> print("hello, world")\nhello, world\nFinally, you can also compile Swift code and run it as a binary:
\n\n% swiftc -o fibonacci fibonacci.swift\n% ./fibonacci 7\n13\nAs with C and other languages, you can compile multiple Swift files:
\n\n% swiftc first.swift second.swift third.swift -o program\nNote: These instructions are valid on macOS Sierra with Xcode 8.3 and Swift 3.1, but as the Swift language evolves they may change.
\n" } ] }