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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.
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”?
cat $(ls -t) > outputfile, otherwise cat rejects the quoted file names
– Mike Pennington
Jun 16 '12 at 9:50
cat $(ls -t) is also vulnerable to filename expansion. If there's a filename with an *, or ?, or a bracket expression (e.g. file-[old].html); and if the filename interpreted as a pattern matches other filenames; the approach will produce an incorrect list. set -f would address this deficiency.
– Barefoot IO
Feb 20 '16 at 19:42
ls -Q may produce output which is not suitable for xargs. For example, "foo" becomes "\"foo\"", but xargs does not understand escaped double quotes within double quoted strings.
– Barefoot IO
Feb 20 '16 at 20:04
The easiest way of listing files in an order other than lexicographic is with zsh glob qualifiers. Without zsh, you can use ls, but parsing the output of ls is fraught with dangers.
cat *(om)
If you want to strip some lines, use sed or awk or perl. For example, to take the <head> from the first file and combine the <body> parts from the other files, assuming that the <body> and </body> tags are alone on a line in every file:
{
sed -e '/<\/body>/ q' *.html(om[2])
sed -e '1,/<body>/ d' -e '/<\/body>/,$ d' *.html(om[3,-1])
echo '</body>'
echo '</html>'
} >concatenated.html
Explanation:
concatenated.html is created. It is therefore the youngest *.html file (assuming no file has a date in the future.*.html file, but quit at the </body> line.<body> line and starting with the </body> line.
Solution given by @angus is good but will have issues if there are directories in the folder this will fix it.
cat $(ls -tpa | grep -v / )
