Tell me more ×
Unix & Linux Stack Exchange is a question and answer site for users of Linux, FreeBSD and other Un*x-like operating systems.. It's 100% free, no registration required.
up vote 3 down vote favorite

And with the oldest file on bottom?

Also, if I do this, is it also possible to strip out the redundant headers contained within each HTML file? I'm seeing myself concatenate a lot of HTML files up, and it would be nice to reduce the file size of the ultimate file a bit.

share|improve this question

2 Answers

up vote 8 down vote accepted

To concatenate files you use

cat file1 file2 file3 ...

To get a list of quoted filenames sorted by time, newest first, you use

ls -t

Putting it all together,

cat $(ls -t) > outputfile

You might want to give some arguments to ls (eg, *.html).

But if you have filenames with spaces in them, this will not work. My file.html will be assumed to be two filenames: My and file.html. You can make ls quote the filenames, and then use xargs, who understands the quoting, to pass the arguments to cat.

ls -tQ | xargs cat

As for your second question, filtering out parts of files isn't difficult, but it depends on what exactly you want to strip out. What are the “redundant headers”?

share|improve this answer
This isn't working on my debian system... I have to use cat $(ls -t) > outputfile, otherwise cat rejects the quoted file names – Mike Pennington Jun 16 '12 at 9:50
My mistake. I always get caught on these things. See updated answer. – angus Jun 16 '12 at 11:19
Oh - by redundant headers I mean things that are normally put in some header.php/footer.php file, but which are saved separately when saved to HTML (and can really increase the file size when you mass-download PHP pages). – InquilineKea Jun 16 '12 at 15:03
up vote 0 down vote

The easiest way of listing files in an order other than lexicographic is with zsh glob qualifiers. Without zsh, you can use ls, but parsing the output of ls is fraught with dangers.

cat *(om)

If you want to strip some lines, use sed or awk or perl. For example, to take the <head> from the first file and combine the <body> parts from the other files, assuming that the <body> and </body> tags are alone on a line in every file:

{
  sed -e '/<\/body>/ q' *.html(om[2])
  sed -e '1,/<body>/ d' -e '/<\/body>/,$ d' *.html(om[3,-1])
  echo '</body>'
  echo '</html>'
} >concatenated.html

Explanation:

  • First, concatenated.html is created. It is therefore the youngest *.html file (assuming no file has a date in the future.
  • Then copy from the second-youngest *.html file, but quit at the </body> line.
  • Then copy from the other files, but skip everything down to the <body> line and starting with the </body> line.
  • Finally produce the last closing tags.
share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.