How to loop over files in natural order in Bash?

bash natural-sort
Perlnika picture Perlnika · Nov 3, 2011 · Viewed 68.3k times · Source

I am looping over all the files in a directory with the following command:

for i in *.fas; do some_code; done;

However, I get them in this order

vvchr1.fas  
vvchr10.fas  
vvchr11.fas
vvchr2.fas
...

instead of

vvchr1.fas
vvchr2.fas
vvchr3.fas
...

what is natural order.

I have tried sort command, but to no avail.

Answer

catalin.costache picture catalin.costache · Nov 3, 2011 
readarray -d '' entries < <(printf '%s\0' *.fas | sort -zV)
for entry in "${entries[@]}"; do
  # do something with $entry
done

where printf '%s\0' *.fas yields a NUL separated list of directory entries with the extension .fas, and sort -zV sorts them in natural order.

Note that you need GNU sort installed in order for this to work.

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