Concatenate multiple files but include filename as section headers - unix

Question

I would like to concatenate a number of text files into one large file in terminal. I know I can do this using the cat command. However, I would like the filename of each file to precede the "data dump" for that file. Anyone know how to do this?
what I currently have:
file1.txt = bluemoongoodbeer
file2.txt = awesomepossum
file3.txt = hownowbrowncow
cat file1.txt file2.txt file3.txt
desired output:
file1
bluemoongoodbeer
file2
awesomepossum
file3
hownowbrowncow

Answer 1

Was looking for the same thing, and found this to suggest:
tail -n +1 file1.txt file2.txt file3.txt
Output:
==> file1.txt <==
<contents of file1.txt>
==> file2.txt <==
<contents of file2.txt>
==> file3.txt <==
<contents of file3.txt>
If there is only a single file then the header will not be printed. If using GNU utils, you can use -v to always print a header.

Answer 2

I used grep for something similar:
grep "" *.txt
It does not give you a 'header', but prefixes every line with the filename.

Answer 3

This should do the trick as well:
$ find . -type f -print -exec cat {} \;
./file1.txt
Content of file1.txt
./file2.txt
Content of file2.txt
Here is the explanation for the command-line arguments:
find = linux `find` command finds filenames, see `man find` for more info
. = in current directory
-type f = only files, not directories
-print = show found file
-exec = additionally execute another linux command
cat = linux `cat` command, see `man cat`, displays file contents
{} = placeholder for the currently found filename
\; = tell `find` command that it ends now here
You further can combine searches trough boolean operators like -and or -or. find -ls is nice, too.

Answer 4

When there is more than one input file, the more command concatenates them and also includes each filename as a header.
To concatenate to a file:
more *.txt > out.txt
To concatenate to the terminal:
more *.txt | cat
Example output:
::::::::::::::
file1.txt
::::::::::::::
This is
my first file.
::::::::::::::
file2.txt
::::::::::::::
And this is my
second file.

Answer 5

This should do the trick:
for filename in file1.txt file2.txt file3.txt; do
echo "$filename"
cat "$filename"
done > output.txt
or to do this for all text files recursively:
find . -type f -name '*.txt' -print | while read filename; do
echo "$filename"
cat "$filename"
done > output.txt

Answer 6

find . -type f -print0 | xargs -0 -I % sh -c 'echo %; cat %'
This will print the full filename (including path), then the contents of the file. It is also very flexible, as you can use -name "expr" for the find command, and run as many commands as you like on the files.

Answer 7

And the missing awk solution is:
$ awk '(FNR==1){print ">> " FILENAME " <<"}1' *

Answer 8

This is how I normally handle formatting like that:
for i in *; do echo "$i"; echo ; cat "$i"; echo ; done ;
I generally pipe the cat into a grep for specific information.

Answer 9

I like this option
for x in $(ls ./*.php); do echo $x; cat $x | grep -i 'menuItem'; done
Output looks like this:
./debug-things.php
./Facebook.Pixel.Code.php
./footer.trusted.seller.items.php
./GoogleAnalytics.php
./JivositeCode.php
./Live-Messenger.php
./mPopex.php
./NOTIFICATIONS-box.php
./reviewPopUp_Frame.php
$('#top-nav-scroller-pos-<?=$active**MenuItem**;?>').addClass('active');
gotTo**MenuItem**();
./Reviews-Frames-PopUps.php
./social.media.login.btns.php
./social-side-bar.php
./staticWalletsAlerst.php
./tmp-fix.php
./top-nav-scroller.php
$active**MenuItem** = '0';
$active**MenuItem** = '1';
$active**MenuItem** = '2';
$active**MenuItem** = '3';
./Waiting-Overlay.php
./Yandex.Metrika.php

Answer 10

you can use this simple command instead of using a for loop,
ls -ltr | awk '{print $9}' | xargs head

Answer 11

If the files all have the same name or can be matched by find, you can do (e.g.):
find . -name create.sh | xargs tail -n +1
to find, show the path of and cat each file.

Answer 12

If you like colors, try this:
for i in *; do echo; echo $'\e[33;1m'$i$'\e[0m'; cat $i; done | less -R
or:
tail -n +1 * | grep -e $ -e '==.*'
or: (with package 'multitail' installed)
multitail *

Answer 13

Here is a really simple way. You said you want to cat, which implies you want to view the entire file. But you also need the filename printed.
Try this
head -n99999999 * or head -n99999999 file1.txt file2.txt file3.txt
Hope that helps

Answer 14

If you want to replace those ugly ==> <== with something else
tail -n +1 *.txt | sed -e 's/==>/\n###/g' -e 's/<==/###/g' >> "files.txt"
explanation:
tail -n +1 *.txt - output all files in folder with header
sed -e 's/==>/\n###/g' -e 's/<==/###/g' - replace ==> with new line + ### and <== with just ###
>> "files.txt" - output all to a file

Answer 15

find . -type f -exec cat {} \; -print

Answer 16

AIX 7.1 ksh
... glomming onto those who've already mentioned head works for some of us:
$ r head
head file*.txt
==> file1.txt <==
xxx
111
==> file2.txt <==
yyy
222
nyuk nyuk nyuk
==> file3.txt <==
zzz
$
My need is to read the first line; as noted, if you want more than 10 lines, you'll have to add options (head -9999, etc).
Sorry for posting a derivative comment; I don't have sufficient street cred to comment/add to someone's comment.

Answer 17

I made a combination of:
cat /sharedpath/{unique1,unique2,unique3}/filename > newfile
and
tail -n +1 file1 file2
into this:
tail -n +1 /sharedpath/{folder1,folder2,...,folder_n}/file.extension | cat > /sharedpath/newfile
The result is a newfile that contains the content from each subfolder (unique1,unique2..) in the {} brackets, separated by subfolder name.
note unique1=folder1
In my case the file.extension has the same name in all subfolders.

Answer 18

If you want the result in the same format as your desired output you can try:
for file in `ls file{1..3}.txt`; \
do echo $file | cut -d '.' -f 1; \
cat $file ; done;
Result:
file1
bluemoongoodbeer
file2
awesomepossum
file3
hownowbrowncow
You can put echo -e before and after the cut so you have the spacing between the lines as well:
$ for file in `ls file{1..3}.txt`; do echo $file | cut -d '.' -f 1; echo -e; cat $file; echo -e ; done;
Result:
file1
bluemoongoodbeer
file2
awesomepossum
file3
hownowbrowncow

Answer 19

This method will print filename and then file contents:
tail -f file1.txt file2.txt
Output:
==> file1.txt <==
contents of file1.txt ...
contents of file1.txt ...
==> file2.txt <==
contents of file2.txt ...
contents of file2.txt ...

Answer 20

For solving this tasks I usually use the following command:
$ cat file{1..3}.txt >> result.txt
It's a very convenient way to concatenate files if the number of files is quite large.

Answer 21

First I created each file: echo 'information' > file1.txt for each file[123].txt.
Then I printed each file to makes sure information was correct:
tail file?.txt
Then I did this: tail file?.txt >> Mainfile.txt. This created the Mainfile.txt to store the information in each file into a main file.
cat Mainfile.txt confirmed it was okay.
==> file1.txt <==
bluemoongoodbeer
==> file2.txt <==
awesomepossum
==> file3.txt <==
hownowbrowncow