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I have saved many documents as txt. I want to print them together so first I want them together in a single file. The order doesn't matter in this case.

I want a solution that does not involve typing the names of the files to be merged, but one that would just merge all txt files within the folder.

Can I do it with a command or some GUI?


I looked here. Don't know how to use join.

8 Answers 8

43

Use cat with output redirection. Syntax: cat file [file] [[file] ...] > joined-file.

Example with just two files (you can have many more):

$ echo "some text in a file" > file1
$ echo "another file with some text" > file2
$ cat file1 file2 > mergedfiles
$ cat mergedfiles
some text in a file
another file with some text

In case you have "many documents", make use of shell globbing (patterns):

cat input-files-dir/* > joined-file

This will join all files in that directory to the current directory (preventing it to match the output file itself). It is totally independent to the use of cat and output redirection - it's just Bash providing all the files as arguments to cat.


File types

It will just glue (join) files together as you would do with paper and tape. It does not care about the actual file format being capable of handling this. It will work for text files, but not for PDFs, ODTs, etc. Well, it will glue them together, but it's not a valid PDF/ODT anymore.


Order of joining

As phoibos pointed out the shell globbing will result in alphabetical order of file names. This is how Bash and shell globbing works.


Addendum about input file is output file error

When the pattern of the input files matches the very same file as being output, this will cause an error. It's a safety feature. Example: cat *.txt > out.txt run the second time will cause this.

What you can do about it:

  • Choose a more specific pattern to match the actual input files, not matching the output name. Example: input files pattern *.txt with output file output.out will not collide.
  • Work in different directories. In the example above I've used a separate input-files-dir directory to place all files in, and output to the current working directory. This makes it impossible to get this error.
14
  • @cipricus Yes, but that's very basic shell globbing (patterns). Try out your patterns using ls to just list the matches. E.g. ls *.txt to see what is being matched.
    – gertvdijk
    Feb 2, 2013 at 13:23
  • 2
    @cipricus How about cat *.txt > JoinedFile.txt ?
    – Sadi
    Feb 2, 2013 at 13:34
  • 1
    This is more common sense actually, cat first catches all .txt files and second it joins them and third it creates a new .txt file which cannot be caught at the first step ;-)
    – Sadi
    Feb 2, 2013 at 13:42
  • 1
    @cipricus It just joins files. Like you would by using pieces of paper with glue and tape! Most "documents" file formats like PDF, which are compressed do not allow this. Use a PDF editor. But anyway, your question was about text files.
    – gertvdijk
    Feb 2, 2013 at 14:25
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    I fully understand that the method you suggest (creating a subdir, moving files and then joining) might be a better way in some cases. But if we just want to join all the text files (all having .txt extension) in the current directory cat *.txt > JoinedFile.txt does the job perfectly. I just tested it out of curiosity and it works, and it seems cipricus has also found the same result. ( And the system has begun complaining that we shouldn't be chatting here, otherwise I would ask if you can teach this novice how you can use formatting in these comments without a toolbar ;-)
    – Sadi
    Feb 2, 2013 at 17:29
12

A simple way to do that is by using cat:

cat file1 file2 > joined_file

If you just issue cat file1 file2 you'll see both files on the standard output. By using >, you're just redirecting the standard output to a file. That will work also with another commands.

4
  • Please read the question. You are telling to specify individual file names, which the OP specifically didn't want to do!
    – Sri
    Feb 6, 2013 at 3:48
  • 2
    That was not in the original question. I've not updated my answer since more complete answers appeared. Feb 6, 2013 at 8:37
  • @JorgeSuárezdeLis While this answer doesn't directly help OP with his/her question, please do note that this answer probably will help someone else who just has a few files they'd like to merge. (oh hey, like me! thank you! ^-^) +1
    – Souta
    Feb 7, 2013 at 22:54
  • @JorgeSuárezdeLis Indeed. You've answered revision 2 of the question perfectly fine. A few minutes later, revision 3, changed the requirements about answers.
    – gertvdijk
    Feb 8, 2013 at 0:04
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Do it with a simple loop:

for i in *.txt; do cat "$i" >> complete.txt; done

>> appends to the file.

Note: If for some reason you have to run the command again, you have to remove complete.txt, otherwise you'd write the file to itself, which doesn't work.

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  • 5
    This will work as well, but I don't see the need for a for-loop if you can use arguments to cat.
    – gertvdijk
    Feb 2, 2013 at 13:37
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    Yes, you're right of course. I'm just not sure about the sord order using cat *.txt. The for loop should be sorted.
    – phoibos
    Feb 2, 2013 at 13:47
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    Turns out, * is guaranteed to be in alphabetical order.
    – phoibos
    Feb 2, 2013 at 13:54
  • Yes, it's the exact same shell globbing. It doesn't matter whether you use it in for or anywhere else in Bash.
    – gertvdijk
    Feb 2, 2013 at 13:56
4

If the files you want to combine all end in .txt, keep it simple:

cat *.txt > combined.txt

If the directory only contains text files, it's also simple:

cat * > combined.txt

(Note that once you create combined.txt, doing it again would include it in the expansion of *, leading to odd behavior).

If you want to select some files in the directory and not others, it's best if the filenames allow you to distinguish which ones you want. If not, you can get fancy with find. But I doubt you need to go that far.

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  • thnx. if you look at the comments to the accepted answer, Sadi suggested exactly that in a comment. if your answer had been the first yours would have been what i need. take a look at mine too: added that in custom menu
    – user47206
    Feb 2, 2013 at 22:04
  • Thanks for the feedback. Yeah, I see it now, it was a bit obscured...
    – alexis
    Feb 3, 2013 at 0:18
4

Thunar custom action script written by cipricus also inspired me to write a similar Nautilus script and I thought it might be useful for others who look at this Q&A for reference on this subject. So here it is:

#!/bin/sh
#Nautilus Script to join selected text files in a single file and open the joined file with default text editor
#
IFS=$'\n'
FILENAME="JoinedFile_$(date +%Y-%m-%d-%H-%M-%S).txt"
cat "$@" > "$FILENAME"
xdg-open "$FILENAME"
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  • @David Foerster Thanks for the edit. I didn't have any problems with the old version (with my limited test cases) and I don't see any problem with this improved version either. Sorry if I caused any inconvenience due to a flaw in the previous version.
    – Sadi
    Aug 21, 2015 at 12:27
  • It wasn't flawed, but it contained an unnecessary loop, which made the code more difficult to understand, imho. Aug 21, 2015 at 22:56
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This is a complement and a variation to the other answers, related to putting these solutions to work in Thunar's custom's actions.

Not all of them are usable in this way, but some are.

I thought that most interesting would be to be able to merge selected files from Thunar's context menu.

This is a variation from what was suggested by Sadi in a comment to gertvdijk's answer :

   cat %N > JoinedFile

Only selected files will be joined. Restrict appearance conditions to text files.

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Special thanks to Sadi whose comment provided me with the most clear and up-to-point solution to my problem.

I accepted gertvdijk's answer as definitive. Not only it was the occasion to Sadi's comment, but is seems to be of further value to others, providing a well argued and complete solution (albeit somewhat above my CLI reading skills).

2

You could try find command also,

find . -name "*.txt" -type f -exec cat {} + > file

It finds .txt files inside the current directory and execute cat command on each founded file. Finally the whole output was redirected to the filename file(created within the current directly itself).

Explanation:

.                  # current directory

-name              # helps to find only .txt files.

-type f            # Only files

-exec cat {} +     # helps to run cat command on the founded .txt files.

>                  # Output redirection operator

file               # to store final output.
-2

You could also just use an online utility such as merge-files-online.com

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