How to append contents of multiple files into one file

I want to copy the contents of five files to one file as is. I tried doing it using cp for each file. But that overwrites the contents copied from the previous file. I also tried

paste -d "\n" 1.txt 0.txt 

and it did not work.

I want my script to add the newline at the end of each text file.

eg. Files 1.txt, 2.txt, 3.txt. Put contents of 1,2,3 in 0.txt

How do I do it ?

12 Answers

You need the cat (short for concatenate) command, with shell redirection (>) into your output file

cat 1.txt 2.txt 3.txt > 0.txt 

Another option, for those of you who still stumble upon this post like I did, is to use find -exec:

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

In my case, I needed a more robust option that would look through multiple subdirectories so I chose to use find. Breaking it down:

find . 

Look within the current working directory.

-type f 

Only interested in files, not directories, etc.

-name '*.txt' 

Whittle down the result set by name

-exec cat {} + 

Execute the cat command for each result. "+" means only 1 instance of cat is spawned (thx @gniourf_gniourf)

 >> output.file 

As explained in other answers, append the cat-ed contents to the end of an output file.

if you have a certain output type then do something like this

cat /path/to/files/*.txt >> finalout.txt 

If all your files are named similarly you could simply do:

cat *.log >> output.log 

If all your files are in single directory you can simply do

cat * > 0.txt

Files 1.txt,2.txt, .. will go into 0.txt

for i in {1..3}; do cat "$i.txt" >> 0.txt; done 

I found this page because I needed to join 952 files together into one. I found this to work much better if you have many files. This will do a loop for however many numbers you need and cat each one using >> to append onto the end of 0.txt.

Edit:

as brought up in the comments:

cat {1..3}.txt >> 0.txt 

or

cat {0..3}.txt >> all.txt 

Another option is sed:

sed r 1.txt 2.txt 3.txt > merge.txt 

Or...

sed h 1.txt 2.txt 3.txt > merge.txt 

Or...

sed -n p 1.txt 2.txt 3.txt > merge.txt # -n is mandatory here 

Or without redirection ...

sed wmerge.txt 1.txt 2.txt 3.txt 

Note that last line write also merge.txt (not wmerge.txt!). You can use w"merge.txt" to avoid confusion with the file name, and -n for silent output.

Of course, you can also shorten the file list with wildcards. For instance, in case of numbered files as in the above examples, you can specify the range with braces in this way:

sed -n w"merge.txt" {1..3}.txt 

if your files contain headers and you want remove them in the output file, you can use:

for f in `ls *.txt`; do sed '2,$!d' $f >> 0.out; done 

All of the (text-) files into one

find . | xargs cat > outfile 

xargs makes the output-lines of find . the arguments of cat.

find has many options, like -name '*.txt' or -type.

you should check them out if you want to use it in your pipeline

If the original file contains non-printable characters, they will be lost when using the cat command. Using 'cat -v', the non-printables will be converted to visible character strings, but the output file would still not contain the actual non-printables characters in the original file. With a small number of files, an alternative might be to open the first file in an editor (e.g. vim) that handles non-printing characters. Then maneuver to the bottom of the file and enter ":r second_file_name". That will pull in the second file, including non-printing characters. The same could be done for additional files. When all files have been read in, enter ":w". The end result is that the first file will now contain what it did originally, plus the content of the files that were read in.

If you want to append contents of 3 files into one file, then the following command will be a good choice:

cat file1 file2 file3 | tee -a file4 > /dev/null 

It will combine the contents of all files into file4, throwing console output to /dev/null.

Send multi file to a file(textall.txt):

cat *.txt > textall.txt