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@rockpapergoat
Created April 12, 2012 04:01
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comparing version numbers is lame
#!/usr/bin/env ruby
# from puppet's package util
def versioncmp(version_a, version_b)
vre = /[-.]|\d+|[^-.\d]+/
ax = version_a.scan(vre)
bx = version_b.scan(vre)
while (ax.length>0 && bx.length>0)
a = ax.shift
b = bx.shift
if( a == b ) then next
elsif (a == '-' && b == '-') then next
elsif (a == '-') then return -1
elsif (b == '-') then return 1
elsif (a == '.' && b == '.') then next
elsif (a == '.' ) then return -1
elsif (b == '.' ) then return 1
elsif (a =~ /^\d+$/ && b =~ /^\d+$/) then
if( a =~ /^0/ or b =~ /^0/ ) then
return a.to_s.upcase <=> b.to_s.upcase
end
return a.to_i <=> b.to_i
else
return a.upcase <=> b.upcase
end
end
version_a <=> version_b;
end
p versioncmp("3.2.46","3.2.45")
@rockpapergoat
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i was going to approach this by turning the version strings into hashes with the array indices as keys, then comparing the two hashes, key by key. then i dug this from puppet's innards. it appears to work fine, though i don't know if the hash method is any better.

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