--- title: Zsh: manipulate filenames with modifiers like :r (root)... description: Zsh offers built-in filename modifiers as suffixes on parameter expansions to slice up paths without calling external commands like dirname or basename. The... canonical: https://daily.dev/posts/zsh-manipulate-filenames-with-modifiers-like-r-root-and-e-extension--0bvafqoyh twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Zsh: manipulate filenames with modifiers like :r (root) and :e (extension) | daily.dev og:description: Zsh offers built-in filename modifiers as suffixes on parameter expansions to slice up paths without calling external commands like dirname or basename. The... og:url: https://daily.dev/posts/zsh-manipulate-filenames-with-modifiers-like-r-root-and-e-extension--0bvafqoyh og:image: https://api.daily.dev/og/posts/0BVafqOyH.png og:image:alt: Zsh: manipulate filenames with modifiers like :r (root) and :e (extension) og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Zsh: manipulate filenames with modifiers like :r (root) and :e (extension) **[Adam Johnson](https://daily.dev/sources/adamj)** · 2 min read · 1 upvotes · 0 comments ## Summary Zsh offers built-in filename modifiers as suffixes on parameter expansions to slice up paths without calling external commands like dirname or basename. The four core modifiers are :h (head, directory part), :t (tail, filename part), :r (root, strips extension), and :e (extension, keeps only extension), and they can be chained left to right, e.g. :t:r reduces a full path to a bare filename. A practical example shows using :r in a loop to batch-convert PNG images to WebP with ImageMagick's magick command, building output filenames like robot.webp from robot.png. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### How do I strip the file extension from a filename in a zsh script? Use the :r modifier on a parameter expansion, which drops the extension and returns the root of the path. For example, if f=talks/robot.png, then ${f:r} returns talks/robot. Combine it with :t (tail) as ${f:t:r} to get just the bare filename without directory or extension, e.g. robot. _Developers scripting file conversions in zsh can find more shell parameter tricks on daily.dev._ ### How can I batch convert PNG images to WebP using a zsh loop and ImageMagick? Loop over the files with for i in *.png; do magick $i ${i:r}.webp; done. The magick command from ImageMagick infers input and output formats from file extensions, and the :r modifier strips .png from the filename before appending .webp to build the output name. Zsh does not word-split unquoted variables, so filenames with spaces stay safe without quoting. _Anyone automating image format conversions can browse more shell and tooling tips on daily.dev._ ## Similar posts on daily.dev - [Zsh: select generated files with \(om\[1\]\) glob qualifiers](https://daily.dev/posts/zsh-select-generated-files-with-om-1-glob-qualifiers-fbfmj2ts0) · Adam Johnson · 0 upvotes · 0 comments - [A shell exclamation mark is not for yelling. Be lazy](https://daily.dev/posts/a-shell-exclamation-mark-is-not-for-yelling-be-lazy-ota4wgej1) · Lobsters · 0 upvotes · 0 comments - [Zsh: tab complete glob qualifiers](https://daily.dev/posts/zsh-tab-complete-glob-qualifiers-trzdr8umc) · Adam Johnson · 1 upvotes · 0 comments --- Tags: [#cli](https://daily.dev/tags/cli), [#shell](https://daily.dev/tags/shell), [#bash](https://daily.dev/tags/bash) [View this post on daily.dev](https://daily.dev/posts/zsh-manipulate-filenames-with-modifiers-like-r-root-and-e-extension--0bvafqoyh) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Zsh: manipulate filenames with modifiers like :r (root) and :e (extension)","url":"https://daily.dev/posts/zsh-manipulate-filenames-with-modifiers-like-r-root-and-e-extension--0bvafqoyh","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/zsh-manipulate-filenames-with-modifiers-like-r-root-and-e-extension--0bvafqoyh"},"datePublished":"2026-08-24T23:20:42.821Z","dateModified":"2026-09-14T06:43:03.262Z","description":"Zsh offers built-in filename modifiers as suffixes on parameter expansions to slice up paths without calling external commands like dirname or basename. 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For example, if f=talks/robot.png, then ${f:r} returns talks/robot. Combine it with :t (tail) as ${f:t:r} to get just the bare filename without directory or extension, e.g. robot. Developers scripting file conversions in zsh can find more shell parameter tricks on daily.dev."}},{"@type":"Question","name":"How can I batch convert PNG images to WebP using a zsh loop and ImageMagick?","acceptedAnswer":{"@type":"Answer","text":"Loop over the files with for i in *.png; do magick $i ${i:r}.webp; done. The magick command from ImageMagick infers input and output formats from file extensions, and the :r modifier strips .png from the filename before appending .webp to build the output name. Zsh does not word-split unquoted variables, so filenames with spaces stay safe without quoting. Anyone automating image format conversions can browse more shell and tooling tips on daily.dev."}}]} ```