How can two files in one of my folders have the same name?

Question

I downloaded two files, they were both saved to the same filename and then I transferred them with scp to another computer.

Why didn't they become one when the second was saved?

Better yet, `ls -lb` (or `ls -lab`, if the name begins with `.`). — G-Man Says 'Reinstate Monica', Aug 15 '14 at 21:45
Also, what, exactly, happened? You downloaded `dir1/foo` and `dir2/foo` on machine X, then `scp`'ed them to `dir42` on machine Y, and they came out as separate files with the same name? Or you downloaded two files with the same name into the same directory (on machine X), and they came out as separate files with the same name? — G-Man Says 'Reinstate Monica', Aug 15 '14 at 21:48

score 41 · Accepted Answer · edited Apr 13 '17 at 12:36

41

Maybe they only look like they have the same name.

Try:

$ touch Stéphane Stéphane Stéphane\  Stéphane
$ ls -1
Stéphane
Stéphane
Stéphane
Stéphane

They look pretty much the same.

$ ls -1b
Stéphane
Stéphane
Stéphane
Stéphane\

Slightly better. The space character is flagged as \ (though not all ls implementations do that).

$ LC_ALL=C ls -1b
Ste\314\201phane
St\303\251phane
St\303\251phane\ 
St\342\200\213\303\251phane

Now we're talking (all non-ASCII characters are rendered as the octal value of their byte constituents)

You could also do, and that works for any input:

$ ls | LC_ALL=C sed -n l
Ste\314\201phane$
St\303\251phane$
St\342\200\213\303\251phane$
St\303\251phane $

Here, the end of lines is marked with $ which makes it easier to spot the trailing space. However, that won't help spotting a file called Stéphane<newline>Stéphane

$ ls | perl -Mopen=locale -MUnicode::UCD=charinfo -lpe '
       s/[^\41-\177]/"<".charinfo(ord$&)->{name}.">"/ge'
Ste<COMBINING ACUTE ACCENT>phane
St<LATIN SMALL LETTER E WITH ACUTE>phane
St<ZERO WIDTH SPACE><LATIN SMALL LETTER E WITH ACUTE>phane
St<LATIN SMALL LETTER E WITH ACUTE>phane<SPACE>

Makes it clearer what happened.

See also this other answer for more on the subject.

edited Apr 13 '17 at 12:36

Community

1

answered Aug 15 '14 at 21:57

Stéphane Chazelas

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If you don't mind me asking Stephane, what does the piped command `LC_ALL=C sed -n 1` do? – ryekayo Aug 15 '14 at 21:59
3

`sed`'s `l` command displays the input in visually unambiguous form. With LC_ALL=C, we make sure it uses only ASCII characters for that (though at least with GNU `sed`, it is not necessary). – Stéphane Chazelas Aug 15 '14 at 22:07
2

@StéphaneChazelas You can also use: `LC_ALL=C ls -b` – vinc17 Aug 16 '14 at 00:11
@vinc17, good point, that's also better than sed to spot files with newline characters, but not always to spot trailing space. I've added it to the answer. – Stéphane Chazelas Aug 16 '14 at 07:11
Damn, TIL that you can have spaces at the end of a file name and it looks like there are two identically names files on the filesystem.! Great answer, `ls | LC_ALL=C sed -n l` really was a big time saver just now, thanks! – Elijah Lynn Mar 16 '20 at 01:06
The command `ls | LC_ALL=C sed -n l` helps me find out that my other filename has a space behind! – Ting Yi Shih May 24 '20 at 14:38

How can two files in one of my folders have the same name?

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