unix join separator char

Question

Sorry for the maybe trivial question.

I fought a bit with the unix join command, trying to get tabs instead of whitespaces as the default separators. -t is the argument, but these don't work (ubuntu 9.10 64 bit 2.6.31-14, GNU coreutils version 7.4)

join file1 file2 -t"\t"
join file1 file2 -t="\t"
join file1 file2 -t="\\t"
join file1 file2 -t $"\t"

Et cetera. Of course, I can always use some inelegant solution like

join file1 file2 > output
sed "s/ /\t/g" output

But I wanted to look smart :-) Moreover, if there's a -t argument, it must work.

when use -t, as stated in man page, it says "Use character CHAR as the input and output field separator." when both your files have same terminator, then it works. — ghostdog74, Nov 12 '09 at 14:13

score 60 · Accepted Answer · answered Nov 12 '09 at 14:06

60

I think it takes a variable generated on-the-fly

Try

join file1 file12 -t $'\t'

answered Nov 12 '09 at 14:06

Tonio

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Cool. I didn't know the `$'...'` syntax before. – Boldewyn Nov 12 '09 at 14:16
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The `$'...'` syntax is [ANSI-C Quoting](https://www.gnu.org/software/bash/manual/bash.html#ANSI_002dC-Quoting). – sebelk Apr 25 '16 at 18:38

score 6 · Answer 2 · answered Sep 06 '12 at 20:53

6

You can enter tab by pressing CTRL+v Tab

join -t '<CTRL+v><Tab>' file1 file2

answered Sep 06 '12 at 20:53

citrin

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score 3 · Answer 3 · answered May 02 '10 at 13:27

3

join -t "`echo '\t'`" file1 file2

ps: on my machine, Red Hat Enterprise Linux Server release 5.1 (Tikanga), the command join -t $'\t' file1 file2 returns "Illegal variable name".

answered May 02 '10 at 13:27

tflutre

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Thanks for adding a distro-specific solution – Federico Giorgi Mar 01 '12 at 18:28
That it does not work on Fedora 23, it outpus nothing. – sebelk Apr 25 '16 at 18:40

score 3 · Answer 4 · answered Feb 20 '15 at 22:48

An alternate trick that seems to work is to enclose the -t option in quotes with the literal tab character. This looks like:

join '-t    ' ...

with a variable space between the t and the closing quote (since it's a tab).

Typed, it's:

join<Spc>'-t<Ctrl-v><Tab>' ...

Boldewyn · Answer 5 · 2009-11-12T14:16:58.360

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man join says, that the options have to come in front of the filenames. Have you tried

join -t "\t" file1 file2

?

Edit: Reflecting Tonio's answer, the correct line would read

join -t $'\t' file1 file2

edited Nov 12 '09 at 14:16

answered Nov 12 '09 at 13:58

Boldewyn

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Yep, doesn't work. It gives the error: join: multi-character tab `\\t' – Federico Giorgi Nov 12 '09 at 13:59
Remove the quotes? At least the error message disappears on my terminal. – Boldewyn Nov 12 '09 at 14:01
I agree, error disappears, but the output is wrongly empty like this :-/ – Federico Giorgi Nov 12 '09 at 14:04
Worth noting that `$'\t'` is a bashism and won't work in all shells. – David C. Rankin Jul 20 '23 at 03:54

score 1 · Answer 6 · answered Apr 25 '16 at 19:07

1

Other way is:

join -t "`echo -e "\t"`" file1 file2`

or in a more bash-fashion:

join -t "$(echo -e "\t")" file1 file

answered Apr 25 '16 at 19:07

sebelk

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unix join separator char

6 Answers6

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