问题
This is my folder structure.
/home/files/encounters 9-22-11-0.jpg .. /home/files/encounters 9-22-11-[n].jpg
puts Dir.glob("/home/files/*.jpg")[0]
When i execute the above code, it displayed the sixth file (index 5 => /home/files/encounters 9-22-11-5.jpg), but actually i need the output as first file(index 0 => /home/files/encounters 9-22-11-0.jpg)
How can i sort the files as user defined sorting order?. like
When i tried..
..[0] => /home/files/encounters 9-22-11-5.jpg
..[1] => /home/files/encounters 9-22-11-21.jpg
..[2] => /home/files/encounters 9-22-11-39.jpg
But, I need
..[0] => /home/files/encounters 9-22-11-0.jpg
..[1] => /home/files/encounters 9-22-11-1.jpg
..[2] => /home/files/encounters 9-22-11-2.jpg
Additional information, sorting is also not working.
f = Dir.glob("/home/files/*.jpg").sort
f[0] => /home/files/encounters 9-22-11-0.jpg
f[0] => /home/files/encounters 9-22-11-1.jpg
f[0] => /home/files/encounters 9-22-11-10.jpg
f[0] => /home/files/encounters 9-22-11-11.jpg
回答1:
puts Dir.glob("/home/files/*.jpg").sort
Would work if you had a format like 11-09-22-05.jpg instead of 9-22-11-5.jpg. You could try to sort them as a number instead.
Dir.glob("/home/files/*.jpg").sort_by {|s| s.gsub("-","").to_i }
But as it seems you have month-day-year-number I guess that the correct way to sort is a bit more complicated than that.
arr=%w[9-22-12-33.jpg 9-22-11-5.jpg 9-22-10-99.jpg 12-24-11-1.jpg]
arr.sort_by do |s|
t = s.split("-").map(&:to_i)
[t[2], t[0], t[1], t[3]]
end
It works by reformatting 9-22-11-5.jpg to an array containing [11, 9, 22, 5] and then sorts by that instead.
回答2:
If possible, I'd create the files with a fixed width numeric format instead:
encounters 9-22-11-05.jpg
encounters 9-22-11-11.jpg
encounters 9-22-11-99.jpg
If that's impossible, you can extract the last numeric part and use that in a custom sort criterion:
a = Dir.glob("*.jpg")
r = Regexp.new(".*-([0-9]+).jpg")
b = a.sort do |f1, f2|
n1 = r.match(f1)[1].to_i
n2 = r.match(f2)[1].to_i
n1 <=> n2
end
puts b
This extracts the last numeric part from each filename (using a regular expression) and sorts by this.
If you have files belonging to different dates, you'll have to modify this so it sorts by their "base" names plus the numeric part.
来源：https://stackoverflow.com/questions/7819911/sort-and-list-the-files-from-a-directory-in-numeric-order