Xjyuk

Is a memoized pure function itself considered pure?

Hangman game in Python - need feedback on the quality of code

LINQ for generating all possible permutations

What's the point of fighting monsters in Zelda BoTW?

Why does the `ls` command sort files like this?

3D cryptic featuring Mao, Stalin and Simba's uncle

How many petaflops does it take to land on the moon? What does Artemis need with an Aitken?

Should open strings on guitar be tuned to the key of the song played?

If I said I had $100 when asked, but I actually had $200, would I be lying by omission?

Unlock your Lock

How can I draw lines between cells from two different tabulars to indicate correlation?

Is the internet in Madagascar faster than in UK?

Is there a word or phrase that means "use other people's wifi or Internet service without consent"?

Joining lists with same elements

Why is the UK so keen to remove the "backstop" when their leadership seems to think that no border will be needed in Northern Ireland?

Retroactively modifying humans for Earth?

Changing JPEG to RAW to use on Lightroom?

74S vs 74LS ICs

Open subspaces of CW complexes

Do you pay one or two mana to bounce a transformed Delver of Secrets with Repeal?

Why did my folder names end up like this, and how can I fix this using a script?

Weighted smooth histogram

How to prevent a hosting company from accessing a VM's encryption keys?

Why does matter stays collapsed following the supernova explosion?

Why does the `ls` command sort files like this?

Why does 'sort' ignore special characters, like the asterisk?Can I sort files A-Z and at the same time Z-A?Lotus notes 8.5 Inbox return to default sort and select next unread emailUnix shell: Multi-level sort in opposite directionsWhy does here-string argument to echo omit first word?What does “>> file command” do, and how does it differ from “command >> file”?Why does plink or bash not recognize command on first line of remote commands file?

.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty margin-bottom:0;

6

2

As I was trying to reverse engineer the ls command, I came upon an interesting behavior. When I make 3 files, foo.png, foopa.png, and fooqa.png, ls sorts them as foopa.png, foo.png, and fooqa.png. I also tried it using the .gif extension and it seems to be that it happens when p and q are replaced by the first letter of the extension and the next letter in the alphabet; so in the case of .gif it would be g and h. (fooga.gif, then foo.gif, then fooha.gif)

Why does it order the output this way?

linux command-line sorting ls coreutils

share|improve this question

edited 8 hours ago

mooncat39

asked 9 hours ago

mooncat39mooncat39

3144 bronze badges

New contributor

mooncat39 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  Don't post links to images of text.
  
  – RalfFriedl
  8 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @RalfFriedl Oh sorry about that, I'll fix it
  
  – mooncat39
  8 hours ago
  

  
  
  
  

add a comment | 

6

2

As I was trying to reverse engineer the ls command, I came upon an interesting behavior. When I make 3 files, foo.png, foopa.png, and fooqa.png, ls sorts them as foopa.png, foo.png, and fooqa.png. I also tried it using the .gif extension and it seems to be that it happens when p and q are replaced by the first letter of the extension and the next letter in the alphabet; so in the case of .gif it would be g and h. (fooga.gif, then foo.gif, then fooha.gif)

Why does it order the output this way?

linux command-line sorting ls coreutils

share|improve this question

edited 8 hours ago

mooncat39

asked 9 hours ago

mooncat39mooncat39

3144 bronze badges

New contributor

mooncat39 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  Don't post links to images of text.
  
  – RalfFriedl
  8 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @RalfFriedl Oh sorry about that, I'll fix it
  
  – mooncat39
  8 hours ago
  

  
  
  
  

add a comment | 

As I was trying to reverse engineer the ls command, I came upon an interesting behavior. When I make 3 files, foo.png, foopa.png, and fooqa.png, ls sorts them as foopa.png, foo.png, and fooqa.png. I also tried it using the .gif extension and it seems to be that it happens when p and q are replaced by the first letter of the extension and the next letter in the alphabet; so in the case of .gif it would be g and h. (fooga.gif, then foo.gif, then fooha.gif)

Why does it order the output this way?

linux command-line sorting ls coreutils

share|improve this question

edited 8 hours ago

mooncat39

asked 9 hours ago

mooncat39mooncat39

3144 bronze badges

New contributor

mooncat39 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

share|improve this question

edited 8 hours ago

mooncat39

asked 9 hours ago

mooncat39mooncat39

3144 bronze badges

New contributor

mooncat39 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

share|improve this question

edited 8 hours ago

mooncat39

asked 9 hours ago

mooncat39mooncat39

3144 bronze badges

New contributor

mooncat39 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

asked 9 hours ago

mooncat39mooncat39

3144 bronze badges

New contributor

mooncat39 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

asked 9 hours ago

mooncat39mooncat39

3144 bronze badges

2 Answers
2

active

oldest

votes

2

It depends on the collation order of your locale:

>LANG=en_IE.UTF-8 ls -1 foo*
foopa.png
foo.png
fooqa.png

>LANG=C ls -1 foo*
foo.png
foopa.png
fooqa.png

C collation order is purely alphabetical (ASCII order). Other collation orders (such as English) may consider spaces and special characters such as dots as separators and either handle "words" separately or just ignore these separators (which appears to be the case here).

Note that the non-UTF-8 locale sorts using alphabetic ASCII, too:

>LANG=en_IE ls -1 foo*
foo.png
foopa.png
fooqa.png

share|improve this answer

edited 6 hours ago

answered 7 hours ago

xenoidxenoid

5,32833 gold badges1010 silver badges2121 bronze badges

add a comment | 

1

ls sorts alphabetically according to strcoll() unless you tell it otherwise. It doesn't treat the period specially, so it won't sort by the "filename extension" after any periods that are there.

It is perplexing that period comes between p and q in the sort order, though! In the default C locale, period comes before any letters (man ascii).

Here's a concise puzzle for other answerers, which I confirmed with ltrace -e strcoll /bin/ls on Ubuntu 14.04:

Why does f.g come before fga.g,

but f.gif comes after fga.gif?

share|improve this answer

edited 7 hours ago

answered 8 hours ago

Camille GoudeseuneCamille Goudeseune

87211 gold badge1515 silver badges3131 bronze badges

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  This can be explained if the collation order for english just ignores the dots. You get the same order for fg fgag fgif fgagif.
  
  – xenoid
  7 hours ago
  

  
  
  
  

add a comment | 

Your Answer

StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "3"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);

else
createEditor();

);

function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);



);

mooncat39 is a new contributor. Be nice, and check out our Code of Conduct.

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Post as a guest

Name

Email

Required, but never shown

StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fsuperuser.com%2fquestions%2f1475533%2fwhy-does-the-ls-command-sort-files-like-this%23new-answer', 'question_page');

);

Post as a guest

Name

Email

Required, but never shown

2

It depends on the collation order of your locale:

>LANG=en_IE.UTF-8 ls -1 foo*
foopa.png
foo.png
fooqa.png

>LANG=C ls -1 foo*
foo.png
foopa.png
fooqa.png

C collation order is purely alphabetical (ASCII order). Other collation orders (such as English) may consider spaces and special characters such as dots as separators and either handle "words" separately or just ignore these separators (which appears to be the case here).

Note that the non-UTF-8 locale sorts using alphabetic ASCII, too:

>LANG=en_IE ls -1 foo*
foo.png
foopa.png
fooqa.png

share|improve this answer

edited 6 hours ago

answered 7 hours ago

xenoidxenoid

5,32833 gold badges1010 silver badges2121 bronze badges

add a comment | 

2

It depends on the collation order of your locale:

>LANG=en_IE.UTF-8 ls -1 foo*
foopa.png
foo.png
fooqa.png

>LANG=C ls -1 foo*
foo.png
foopa.png
fooqa.png

C collation order is purely alphabetical (ASCII order). Other collation orders (such as English) may consider spaces and special characters such as dots as separators and either handle "words" separately or just ignore these separators (which appears to be the case here).

Note that the non-UTF-8 locale sorts using alphabetic ASCII, too:

>LANG=en_IE ls -1 foo*
foo.png
foopa.png
fooqa.png

share|improve this answer

edited 6 hours ago

answered 7 hours ago

xenoidxenoid

5,32833 gold badges1010 silver badges2121 bronze badges

add a comment | 

It depends on the collation order of your locale:

>LANG=en_IE.UTF-8 ls -1 foo*
foopa.png
foo.png
fooqa.png

>LANG=C ls -1 foo*
foo.png
foopa.png
fooqa.png

C collation order is purely alphabetical (ASCII order). Other collation orders (such as English) may consider spaces and special characters such as dots as separators and either handle "words" separately or just ignore these separators (which appears to be the case here).

Note that the non-UTF-8 locale sorts using alphabetic ASCII, too:

>LANG=en_IE ls -1 foo*
foo.png
foopa.png
fooqa.png

share|improve this answer

edited 6 hours ago

answered 7 hours ago

xenoidxenoid

5,32833 gold badges1010 silver badges2121 bronze badges

>LANG=en_IE.UTF-8 ls -1 foo*
foopa.png
foo.png
fooqa.png

>LANG=C ls -1 foo*
foo.png
foopa.png
fooqa.png

>LANG=en_IE ls -1 foo*
foo.png
foopa.png
fooqa.png

share|improve this answer

edited 6 hours ago

answered 7 hours ago

xenoidxenoid

5,32833 gold badges1010 silver badges2121 bronze badges

answered 7 hours ago

xenoidxenoid

5,32833 gold badges1010 silver badges2121 bronze badges

answered 7 hours ago

xenoidxenoid

5,32833 gold badges1010 silver badges2121 bronze badges

1

ls sorts alphabetically according to strcoll() unless you tell it otherwise. It doesn't treat the period specially, so it won't sort by the "filename extension" after any periods that are there.

It is perplexing that period comes between p and q in the sort order, though! In the default C locale, period comes before any letters (man ascii).

Here's a concise puzzle for other answerers, which I confirmed with ltrace -e strcoll /bin/ls on Ubuntu 14.04:

Why does f.g come before fga.g,

but f.gif comes after fga.gif?

share|improve this answer

edited 7 hours ago

answered 8 hours ago

Camille GoudeseuneCamille Goudeseune

87211 gold badge1515 silver badges3131 bronze badges

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  This can be explained if the collation order for english just ignores the dots. You get the same order for fg fgag fgif fgagif.
  
  – xenoid
  7 hours ago
  

  
  
  
  

add a comment | 

1

ls sorts alphabetically according to strcoll() unless you tell it otherwise. It doesn't treat the period specially, so it won't sort by the "filename extension" after any periods that are there.

It is perplexing that period comes between p and q in the sort order, though! In the default C locale, period comes before any letters (man ascii).

Here's a concise puzzle for other answerers, which I confirmed with ltrace -e strcoll /bin/ls on Ubuntu 14.04:

Why does f.g come before fga.g,

but f.gif comes after fga.gif?

share|improve this answer

edited 7 hours ago

answered 8 hours ago

Camille GoudeseuneCamille Goudeseune

87211 gold badge1515 silver badges3131 bronze badges

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  This can be explained if the collation order for english just ignores the dots. You get the same order for fg fgag fgif fgagif.
  
  – xenoid
  7 hours ago
  

  
  
  
  

add a comment | 

ls sorts alphabetically according to strcoll() unless you tell it otherwise. It doesn't treat the period specially, so it won't sort by the "filename extension" after any periods that are there.

It is perplexing that period comes between p and q in the sort order, though! In the default C locale, period comes before any letters (man ascii).

Here's a concise puzzle for other answerers, which I confirmed with ltrace -e strcoll /bin/ls on Ubuntu 14.04:

Why does f.g come before fga.g,

but f.gif comes after fga.gif?

share|improve this answer

edited 7 hours ago

answered 8 hours ago

Camille GoudeseuneCamille Goudeseune

87211 gold badge1515 silver badges3131 bronze badges

share|improve this answer

edited 7 hours ago

answered 8 hours ago

Camille GoudeseuneCamille Goudeseune

87211 gold badge1515 silver badges3131 bronze badges

answered 8 hours ago

Camille GoudeseuneCamille Goudeseune

87211 gold badge1515 silver badges3131 bronze badges

answered 8 hours ago

Camille GoudeseuneCamille Goudeseune

87211 gold badge1515 silver badges3131 bronze badges