Initial revision of "git", the information manager from hell

Re:Initial revision of "git", the information manager from hell by dspillett on Friday August 17, 2012 @09:00AM (#4396112)

> So ls -i should show they all share the same inode number?

It would, yes. Another useful tool here is du which by default will screen out files with duplicate inode numbers. So for an example where I have two 100M files each with multiple hard links:

  me@swann:/tmp/tmp$ ls -lhi
  total 701M
  180277 -rw-r--r-- 3 me us 100M Aug 17 13:44 zero.file
  180278 -rw-r--r-- 4 me us 100M Aug 17 13:45 zero.file.2
  180278 -rw-r--r-- 4 me us 100M Aug 17 13:45 zero.file.2.link1
  180278 -rw-r--r-- 4 me us 100M Aug 17 13:45 zero.file.2.link2
  180278 -rw-r--r-- 4 me us 100M Aug 17 13:45 zero.file.2.link3
  180277 -rw-r--r-- 3 me us 100M Aug 17 13:44 zero.file.link
  180277 -rw-r--r-- 3 me us 100M Aug 17 13:44 zero.file.link2
  me@swann:/tmp/tmp$ du -shc *
  101M    zero.file
  101M    zero.file.2
  201M    total

du does this duplicate ignorance trick across whole trees so the links do not have to be in the same directory, and you can have it scan a whole tree and it will show how much space it really taken, not how much is nominally taken. Like so:

  me@swann:/tmp/tmp$ cd ..
  me@swann:/tmp$ du -shc tmp
  201M    tmp
  201M    total

The reason I'm getting 101Mb instead of 100Mb (and 701Mb in total in ls) is that it is counting each link as taking a small amount of space, then "100MByte-plus-a-bit" is being rounded up to 101Mb (and 700-and-a-fraction rounds up to 701).

Also the number in the 3rd column of the ls output above is the number of links to the object, which can be helpful in understanding this sort of situation too.

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Re:Initial revision of "git", the information manager from hell by ggggit on Friday August 17, 2012 @08:32PM (#4399646)

I am no expert with du and all it's options and behaviours, but it's funny you mention the h, c and s ones because I did bother to learn and commit those three to memory long ago and routinely that combination.

I also use routinely use dd to get "exact" file sizes (yes, it's crude, but dd is on almost every UNIX-like system and it works), unless I have access to a good stat utility.

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