How to sort files in a folder using bash?

Question

I have these files in a folder:

chap11-solutions.pdf
chap12-solutions.pdf
chap13-solutions.pdf
chap14-solutions.pdf
chap15-solutions.pdf
chap16-solutions.pdf
chap17-solutions.pdf
chap21-solutions.pdf
chap22-solutions.pdf
chap23-solutions.pdf
chap24-solutions.pdf
chap25-solutions.pdf
chap26-solutions.pdf
chap2-solutions.pdf
chap3-solutions.pdf
chap4-solutions.pdf
chap5-solutions.pdf
chap6-solutions.pdf
chap7-solutions.pdf
chap8-solutions.pdf
chap9-solutions.pdf

how do I sort them in this way: chap1..., chap...2, ...., chap11..., chap12,... using Ubuntu bash shell? Thanks.

Solution 1

ls|sort -V

The -V parameter ensures that chap10 is considered upper that chap9.

Solution 2

GNU ls has a version sort built-in:

ls -lv

Solution 3

If you have ruby(1.9.1+)

ruby -e 'puts Dir["chap*pdf"].sort_by{|x|x[/\d+/].to_i}'

Solution 4

Assuming that you want to rename the files so you don't have to keep sorting them later:

for f in chap*-solutions.pdf; do num=`echo $f | grep -o "[0123456789]\+"`; two_num=`printf "%02d" $num`; mv $f chap$two_num-solutions.pdf; done

• grep -o "[0123456789]+" outputs the chapter number (one or two digits)
• printf returns a string that contains the zero-padded number

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Comments

[Tomasz Elendt]

Just be aware that the -V option works only for relatively new GNU coreutils - it doesn't work for 5.93 (the one that's shipped by default with Mac OS 10.6).

[Arnaud Le Blanc]

OP uses Ubuntu, so he likely have a recent GNU coreutils :)

[wakandan]

thanks for this new very useful info, I never know this old tool got that handful switch. :D

[wakandan]

And this is what they call "thoughtful". It touched my intention of renaming some files. Thanks a lot :D

[wakandan]

One more nice thing about Ruby. Thanks for the info. Good luck in so.com. :D