[{"_1":2,"_192":-5,"_193":-5},"loaderData",{"_3":4,"_17":18,"_25":26,"_167":168},"root",{"_5":-5,"_6":-7,"_7":8,"_9":-7,"_10":11,"_12":-7,"_13":14,"_15":16},"currentUser","primaryEmail","siteVerification","6LeIxAcTAAAAAJcZVRqyHh71UMIEGNQ_MXjiZKhI","toast","enableDev",false,"incidentStatus","theme","system","contrast","normal","routes/_layout",{"_19":-5,"_20":21,"_22":21,"_23":11,"_24":21},"username","isAskGordonEnabled",true,"isUsingNewTemplate","showMinimalLanding","showHoneypotTrap","routes/_layout.r.$namespace.$reponame",{"_27":28,"_29":-5,"_30":11,"_31":11,"_32":33,"_34":35,"_36":-5,"_37":11,"_38":39,"_88":89,"_108":109,"_156":-5,"_157":11,"_158":21,"_159":11,"_160":-5,"_161":11,"_162":-5,"_163":164,"_165":110,"_166":-7},"canonicalUrl","https://hub.docker.com/r/rootnroll/demo-fish-shell/tags","mcpServer","canSeeDockerfile","canSeeAutobuilds","namespace","rootnroll","reponame","demo-fish-shell","cloudBuildSource","isAutobuildsAvailable","repo",{"_40":41,"_42":43,"_45":46,"_47":48,"_49":11,"_50":51,"_52":53,"_54":55,"_57":35,"_32":33,"_58":59,"_60":44,"_61":62,"_63":64,"_65":66,"_67":-5,"_68":62,"_69":70,"_71":11,"_72":33,"_73":74,"_79":21,"_80":81,"_85":33,"_86":87},"categories",[],"content_types",[44],"image","date_registered","2018-03-11T20:05:56.680628Z","description","Image for fish shell demo https://rootnroll.com/d/fish-shell","is_private","last_updated","2019-05-29T11:40:43.867484Z","last_modified","2024-10-16T13:48:34.145251Z","media_types",[56],"application/vnd.docker.container.image.v1+json","name","pull_count",214,"repository_type","star_count",0,"status",1,"status_description","active","source","collaborator_count","full_description","\n\n[fish](https://fishshell.com/) is a fully-equipped command line shell (like bash or zsh) that is smart and user-friendly. `fish` supports powerful features like syntax highlighting, autosuggestions, and tab completions that just work, with nothing to learn or configure.\n\n# Running Commands\n\n`fish` runs commands like other shells: you type a command, followed by its arguments. Spaces are separators:\n\n

> echo hello world\nhello world\n

\n\nYou can include a literal space in an argument with a backslash, or by using single or double quotes:\n\n

> mkdir My\\ Files\n> cp ~/Some\\ File 'My Files'\n> ls \"My Files\"\nSome File\n

\n\nCommands can be chained with semicolons.\n\n# Getting Help\n\n`fish` has excellent help and man pages. Run `help` to open help in a web browser, and `man` to open it in a man page. You can also ask for help with a specific command, for example, `help set` to open in a web browser, or `man set` to see it in the terminal.\n\n

> man set\nset - handle shell variables\n  Synopsis...\n

\n\n# Syntax Highlighting\n\nYou'll quickly notice that `fish` performs syntax highlighting as you type. Invalid commands are colored red by default:\n\n

> /bin/mkd\n

\n\nA command may be invalid because it does not exist, or refers to a file that you cannot execute. When the command becomes valid, it is shown in a different color:\n\n

> /bin/mkdir\n

\n\n`fish` will underline valid file paths as you type them:\n\n

> cat ~/somefi \n

\n\nThis tells you that there exists a file that starts with `somefi`, which is useful feedback as you type.\n\nThese colors, and many more, can be changed by running `fish_config`, or by modifying variables directly.\n\n# Wildcards\n\n`fish` supports the familiar wildcard `*`. To list all JPEG files:\n\n

> ls *.jpg\nlena.jpg\nmeena.jpg\nsanta maria.jpg\n

\n\nYou can include multiple wildcards:\n\n

> ls l*.p*\nlena.png\nlesson.pdf\n

\n\nEspecially powerful is the recursive wildcard `**` which searches directories recursively:\n\n

> ls /var/**.log\n/var/log/system.log\n/var/run/sntp.log\n

\n\nIf that directory traversal is taking a long time, you can Control-C out of it.\n\n# Pipes and Redirections\n\nYou can pipe between commands with the usual vertical bar:\n\n

> echo hello world | wc\n       1       2      12\n

\n\nstdin and stdout can be redirected via the familiar < and >. Unlike other shells, stderr is redirected with a caret ^\n\n

> grep fish < /etc/shells > ~/output.txt ^ ~/errors.txt\n

\n\n# Autosuggestions\n\n`fish` suggests commands as you type, and shows the suggestion to the right of the cursor, in gray. For example:\n\n

> /bin/hostname\n

\n\nIt knows about paths and options:\n\n

> grep --ignore-case\n

\n\nAnd history too. Type a command once, and you can re-summon it by just typing a few letters:\n\n

> r<\\@args{ync} \\ ssh . myname@somelonghost.com:/some/long/path/doo/dee/doo/dee/doo}\n

\n\nTo accept the autosuggestion, hit → or Control-F. To accept a single word of the autosuggestion, Alt-→ (right arrow). If the autosuggestion is not what you want, just ignore it.\n\n# Tab Completions\n\n`fish` comes with a rich set of tab completions, that work \"out of the box.\"\n\nPress Tab, and `fish` will attempt to complete the command, argument, or path:\n\n

> /pri @key{Tab} → /private/\n

\n\nIf there's more than one possibility, it will list them:\n\n

> ~/stuff/s @key{Tab}\n~/stuff/script.sh  (Executable, 4.8kB)  ~/stuff/sources/  (Directory)\n

\n\nHit tab again to cycle through the possibilities.\n\n`fish` can also complete many commands, like git branches:\n\n

> git merge pr @key{Tab} → git merge prompt_designer\n> git checkout b @key{Tab}\nbuiltin_list_io_merge (Branch) builtin_set_color (Branch) busted_events (Tag)\n

\n\nTry hitting tab and see what `fish` can do!\n\n# Variables\n\nLike other shells, a dollar sign performs variable substitution:\n\n

> echo My home directory is $HOME\nMy home directory is /home/tutorial\n

\n\nVariable substitution also occurs in double quotes, but not single quotes:\n\n

> echo \"My current directory is $PWD\"\nMy current directory is /home/tutorial\n> echo 'My current directory is $PWD'\nMy current directory is $PWD\n

\n\nUnlike other shells, `fish` has no dedicated syntax for setting variables. Instead it has an ordinary command: `set`, which takes a variable name, and then its value.\n\n

> set name 'Mister Noodle'\n> echo $name\nMister Noodle\n

\n\n(Notice the quotes: without them, `Mister` and `Noodle` would have been separate arguments, and `$name` would have been made into a list of two elements.)\n\nUnlike other shells, variables are not further split after substitution:\n\n

> mkdir $name\n> ls\nMister Noodle\n

\n\nIn bash, this would have created two directories \"Mister\" and \"Noodle\". In `fish`, it created only one: the variable had the value \"Mister Noodle\", so that is the argument that was passed to `mkdir`, spaces and all. Other shells use the term \"arrays\", rather than lists.\n\n# Exit Status\n\nUnlike other shells, `fish` stores the exit status of the last command in `$status` instead of `$?`.\n\n

> false\n> echo $status\n1\n

\n\nZero is considered success, and non-zero is failure.\n\n# Exports (Shell Variables)\n\nUnlike other shells, `fish` does not have an export command. Instead, a variable is exported via an option to `set`, either `--export` or just `-x`.\n\n

> set -x MyVariable SomeValue\n> env | grep MyVariable\nMyVariable=SomeValue\n

\n\nYou can erase a variable with `-e` or `--erase`\n\n

> set -e MyVariable\n> env | grep MyVariable\n(no output)\n

\n\n# Lists\n\nThe `set` command above used quotes to ensure that `Mister Noodle` was one argument. If it had been two arguments, then `name` would have been a list of length 2. In fact, all variables in `fish` are really lists, that can contain any number of values, or none at all.\n\nSome variables, like `$PWD`, only have one value. By convention, we talk about that variable's value, but we really mean its first (and only) value.\n\nOther variables, like `$PATH`, really do have multiple values. During variable expansion, the variable expands to become multiple arguments:\n\n

> echo $PATH\n/usr/bin /bin /usr/sbin /sbin /usr/local/bin\n

\n\nNote that there are three environment variables that are automatically split on colons to become lists when fish starts running: `PATH`, `CDPATH`, `MANPATH`. Conversely, they are joined on colons when exported to subcommands. All other environment variables (e.g., `LD_LIBRARY_PATH`) which have similar semantics are treated as simple strings.\n\nLists cannot contain other lists: there is no recursion. A variable is a list of strings, full stop.\n\nGet the length of a list with `count`:\n\n

> count $PATH\n5\n

\n\nYou can append (or prepend) to a list by setting the list to itself, with some additional arguments. Here we append /usr/local/bin to $PATH:\n\n

> set PATH $PATH /usr/local/bin\n

\n\nYou can access individual elements with square brackets. Indexing starts at 1 from the beginning, and -1 from the end:\n\n

> echo $PATH\n/usr/bin /bin /usr/sbin /sbin /usr/local/bin\n> echo $PATH[1]\n/usr/bin\n> echo $PATH[-1]\n/usr/local/bin\n

\n\nYou can also access ranges of elements, known as \"slices:\"\n\n

> echo $PATH[1..2]\n/usr/bin /bin\n> echo $PATH[-1..2]\n/usr/local/bin /sbin /usr/sbin /bin\n

\n\nYou can iterate over a list (or a slice) with a for loop:\n\n

> for val in $PATH\n    echo \"entry: $val\"\n  end\nentry: /usr/bin/\nentry: /bin\nentry: /usr/sbin\nentry: /sbin\nentry: /usr/local/bin\n

\n\nLists adjacent to other lists or strings are expanded as [cartesian products](https://fishshell.com/docs/current/index.html#cartesian-product) unless quoted (see [Variable expansion](https://fishshell.com/docs/current/index.html#expand-variable)):\n\n

> set -l a 1 2 3\n> set -l 1 a b c\n> echo $a$1\n1a 2a 3a 1b 2b 3b 1c 2c 3c\n> echo $a\" banana\"\n1 banana 2 banana 3 banana\n> echo \"$a banana\"\n1 2 3 banana\n

\n\nThis is similar to [Brace expansion](https://fishshell.com/docs/current/index.html#expand-brace).\n\n# Command Substitutions\n\nCommand substitutions use the output of one command as an argument to another. Unlike other shells, `fish` does not use backticks ` for command substitutions. Instead, it uses parentheses:\n\n

> echo In (pwd), running (uname)\nIn /home/tutorial, running FreeBSD\n

\n\nA common idiom is to capture the output of a command in a variable:\n\n

> set os (uname)\n> echo $os\nLinux\n

\n\nCommand substitutions are not expanded within quotes. Instead, you can temporarily close the quotes, add the command substitution, and reopen them, all in the same argument:\n\n

> touch \"testing_\"(date +%s)\".txt\"\n> ls *.txt\ntesting_1360099791.txt\n

\n\nUnlike other shells, fish does not split command substitutions on any whitespace (like spaces or tabs), only newlines. This can be an issue with commands like `pkg-config` that print what is meant to be multiple arguments on a single line. To split it on spaces too, use `string split`.\n\n

> printf '%s\\n' (pkg-config --libs gio-2.0)\n-lgio-2.0 -lgobject-2.0 -lglib-2.0\n> printf '%s\\n' (pkg-config --libs gio-2.0 | string split \" \")\n-lgio-2.0\n-lgobject-2.0\n-lglib-2.0\n

\n\n# Separating Commands (Semicolon)\n\nLike other shells, fish allows multiple commands either on separate lines or the same line.\n\nTo write them on the same line, use the semicolon (\";\"). That means the following two examples are equivalent:\n\n

echo fish; echo chips\n\n# or\necho fish\necho chips\n

\n\n# Combiners (And, Or, Not)\n\nUnlike other shells, `fish` does not have special syntax like && or || to combine commands. Instead it has commands `and`, `or`, and `not`.\n\n

> cp file1.txt file1_bak.txt; and echo \"Backup successful\"; or echo \"Backup failed\"\nBackup failed\n

\n\nAs mentioned in [the section on the semicolon](#tut_semicolon), this can also be written in multiple lines, like so:\n\n

cp file1.txt file1_bak.txt\nand echo \"Backup successful\"\nor echo \"Backup failed\"\n

\n\n# Conditionals (If, Else, Switch)\n\nUse `if`, `else if`, and `else` to conditionally execute code, based on the exit status of a command.\n\n

if grep fish /etc/shells\n    echo Found fish\nelse if grep bash /etc/shells\n    echo Found bash\nelse\n    echo Got nothing\nend\n

\n\n[Combiners](#tut_combiners) can also be used to make more complex conditions, like\n\n

if grep fish /etc/shells; and command -sq fish\n    echo fish is installed and configured\nend\n

\n\nFor even more complex conditions, use `begin` and `end` to group parts of them.\n\nThere is also a `switch` command:\n\n

switch (uname<","has_starred","hub_user","immutable_tags_settings",{"_75":11,"_76":77},"enabled","rules",[78],".*","is_automated","permissions",{"_82":21,"_83":11,"_84":11},"read","write","admin","user","storage_size",462022285,"orgData",{"_90":91,"_92":93,"_94":95,"_96":33,"_97":98,"_99":98,"_100":98,"_101":98,"_102":103,"_104":98,"_105":98,"_106":98,"_107":21},"id","2d9b20c474c011e4bea40242ac11001b","uuid","2d9b20c4-74c0-11e4-bea4-0242ac11001b","type","organization","orgname","full_name","","location","company","profile_url","date_joined","2013-11-29T18:46:25Z","gravatar_url","gravatar_email","badge","is_active","recentTags",[110,146],{"_111":44,"_112":113,"_114":115,"_90":116,"_117":118,"_50":135,"_136":113,"_137":33,"_138":56,"_57":139,"_140":141,"_142":126,"_143":135,"_144":66,"_145":21},"content_type","creator",6779,"full_size",99702845,57272838,"images",[119],{"_120":121,"_122":123,"_124":98,"_125":126,"_127":128,"_129":130,"_131":98,"_132":-5,"_133":115,"_63":66,"_134":-5},"architecture","amd64","digest","sha256:72767c1c4026b7ca29471490a151caf5468a48e1a1e33daf39fd9298cdca040f","features","last_pulled","2026-09-25T04:24:46.284791822Z","last_pushed","2019-05-29T11:40:44Z","os","linux","os_features","os_version","size","variant","2019-05-29T11:40:43.50087Z","last_updater","last_updater_username","media_type","3.0.2","repository",4665476,"tag_last_pulled","tag_last_pushed","tag_status","v2",{"_111":44,"_112":113,"_114":147,"_90":148,"_117":149,"_50":154,"_136":113,"_137":33,"_138":56,"_57":155,"_140":141,"_142":152,"_143":154,"_144":66,"_145":21},101606533,23660091,[150],{"_120":121,"_122":151,"_124":98,"_125":152,"_127":153,"_129":130,"_131":98,"_132":-5,"_133":147,"_63":66,"_134":-5},"sha256:7e5a71b16a2c8c1e29bbb7b14e3caf2727dcbd58224b3a5f2d43ee407f56edd5","2026-09-25T14:07:00.789255547Z","2018-10-23T16:26:31Z","2018-10-23T16:26:30.66973Z","2.7.1","sbxKitMetadata","isPotentialSpam","isHubSbxKitsEnabled","showSbxLogoOverride","sbxTrademarkText","displaySecurityMetadata","tagAttestations","tagsHaveAttestations",[],"selectedTag","attestationsUrl","routes/_layout.r.$namespace.$reponame.tags",{"_38":169,"_176":177,"_163":190,"_191":11},{"_40":170,"_42":171,"_45":46,"_47":48,"_49":11,"_50":51,"_52":53,"_54":172,"_57":35,"_32":33,"_58":59,"_60":44,"_61":62,"_63":64,"_65":66,"_67":-5,"_68":62,"_69":70,"_71":11,"_72":33,"_73":173,"_79":21,"_80":175,"_85":33,"_86":87},[],[44],[56],{"_75":11,"_76":174},[78],{"_82":21,"_83":11,"_84":11},"tags",{"_178":179,"_180":-5,"_181":-5,"_182":183},"count",2,"next","previous","results",[184,187],{"_111":44,"_112":113,"_114":115,"_90":116,"_117":185,"_50":135,"_136":113,"_137":33,"_138":56,"_57":139,"_140":141,"_142":126,"_143":135,"_144":66,"_145":21},[186],{"_120":121,"_122":123,"_124":98,"_125":126,"_127":128,"_129":130,"_131":98,"_132":-5,"_133":115,"_63":66,"_134":-5},{"_111":44,"_112":113,"_114":147,"_90":148,"_117":188,"_50":154,"_136":113,"_137":33,"_138":56,"_57":155,"_140":141,"_142":152,"_143":154,"_144":66,"_145":21},[189],{"_120":121,"_122":151,"_124":98,"_125":152,"_127":153,"_129":130,"_131":98,"_132":-5,"_133":147,"_63":66,"_134":-5},[],"canDeleteTags","actionData","errors"]

rootnroll/demo-fish-shell

Tags for rootnroll/demo-fish-shell