23

Is there a command to show the directory or file name when using cat to display the contents of files?

For example: assume two files f1.txt and f2.txt are in ./tmp

./tmp/f1.txt
./tmp/f2.txt

Then when I do cat ./tmp/*.txt, only the content of the files will be shown. But how to first show the file name, then the content? e.g.:

 (The needed command):
 ./tmp/f1.txt:  
 This is from f1.txt
 and so on
 ./tmp/f2.txt:
 This is from f2.txt ...

Is there a command to do it? (There seems to be no option for cat to show the file names.)

Kusalananda
  • 333,661

9 Answers9

36

Just as another idea, try tail -n +1 ./tmp/*.txt

==> ./tmp/file1.txt <==
<contents of file1.txt>

==> ./tmp/file2.txt <==
<contents of file2.txt>


==> ./tmp/file3.txt <==
<contents of file3.txt>
Stéphane Chazelas
  • 544,893
Random832
  • 10,666
11
$ for file in ./tmp/*.txt; do printf '%s\n' "$file";  cat "$file"; done

-or-

$ find ./tmp -maxdepth 1 -name "*.txt" -print -exec cat "{}" \;
Stéphane Chazelas
  • 544,893
kbulgrien
  • 830
5

Not exactly what you asked for, but you can prefix each line with the filename:

$ grep '^' ./tmp/*.txt
./tmp/f1.txt: this is from f1.txt
./tmp/f1.txt: blaa, blaa, blaa...
./tmp/f1.txt: blaa, blaa, blaa...
./tmp/f2.txt: this is from f2.txt
./tmp/f2.txt: blaa, blaa, blaa...
./tmp/f2.txt: blaa, blaa, blaa...

It will be tough to do much better than this without resorting to a little scripting.

Stéphane Chazelas
  • 544,893
Paul R
  • 181
4

Not enough reputation point to add a comment to second answer

tail -v -n +1 /tmp/*.txt

will display filename even if there is only one file.

Pierre-Damien
  • 159
2
grep . *.txt

Matches all lines and also shows file names

Michael Mrozek
  • 93,103
  • 40
  • 240
  • 233
sathiq
  • 39
2

You could easily write a tiny script doing just that,

for f in "$@" do; echo "This is from $f"; cat -- "$f"; done
Gilles 'SO- stop being evil'
  • 829,060
jpmuc
  • 245
  • Thanks, but is there a way to avoid using script - by using a command? –  Aug 28 '12 at 15:49
  • To my knowledge, there is not such a command –  Aug 28 '12 at 15:52
  • 2
    What is the practical difference between a script and a command, or, why does it matter that multiple commands are entered on a single command-line to solve the problem? The command doesn't have to be in a file. You can run the "script" by just typing in the text given. –  Aug 28 '12 at 15:59
  • That is true - but i want to use something existed, please see the answer from "ire_and_curses" and "kbulgrien" –  Aug 28 '12 at 16:14
  • Hello, i typed the given text in the command line of my terminal and it says: "syntax error near unexpected token echo". why does it happen? –  Aug 28 '12 at 16:18
  • @lukmac: Try something more like this: for f in *; do echo "This is from ${f}"; cat $f; done – ire_and_curses Aug 28 '12 at 16:30
  • 3
    Please use "$@" instead of $*, as the former will handle filenames with spaces (this is part of POSIX shell, it's not a bash-ism). Also, cat "$f". – derobert Aug 28 '12 at 16:37
1
find . -name '*' -execdir cat '{}' \;

When a directory is passed to cat, you'll see something like:

cat: ./chapter_01: Is a directory

Immediately following, the find will cat the contents of that directory.

ire_and_curses
  • 12,362
0

cat is (intentionally) an extremely simple command that just reads one file stream and dumps it to another (with a few basic formatting options). It'd be fairly easy to create a utility based on cat that did provide the filename, but standard versions won't do this -- probably because it's easy to replicate with other commands.

If you want to examine the pages manually you could use 'less'. This will give you the filename at the end of every file, in the format: 'foo.txt (file 1 of 100) (END) - Next: bar.txt).

teppic
  • 4,611
0

More gives nice headings, poor cat though:

$ more *.txt | cat
::::::::::::::
file1.txt
::::::::::::::
line1
line2

::::::::::::::
file2.txt
::::::::::::::
line1
line2
line3

...and so on.

kilves76
  • 101