multiple

• You can compile the C-code with your compiler.
  
• You can create the (detailed) documentation from the C-code with troff/groff.
  There is no need for additional tools, because the (t|g)roff-code is embedded inside the C-Comments. :)
  
• With groff you can do the following for creating the detailed docs: $ groff -p multiple.c > multiple.ps
• (But there also is a classical manpage.)
  

What it does

It compares files and detects files with the same contents. Invoked without parameters, if you have n equalfiles, it shows you (n-1) of them, because it assumes, that theese all are superflous (one is enough, you don't need extra copies).

It also can delete them immediately, if the -d switch is active. If you want to compare email- or newsgroup-articles, then it would make sense to only compare the bodies of the mails / postings and ignore the headers. You can invoke multiple with the switch -i (i: ignore headers) to acchieve this goal.

When you delete(-d switch), at least one true regular file will be left over. So, if multiple has a true regualar file and a symbolic link on it, it will remove the symbolic, not the true regular file.

All CLI-options/switches of version 0.4 and 0.5.2:

usage: find | multiple [-a] [-i] [-v] [-h] [-0] [-d]

• option a: print ALL filenames instead of superflous.
  
• option i: compare after first empty line (IGNORE headers).
  
• option v: print version.
  
• option h: print this help message.
  
• option 0: don't ignore files with size == 0
  
• option d: delete superflous files and print name of the non-deleted files.
  Attention! This option ignores read-only-permissions of your files!

AUR-Page (Arch-Linux)

Different Variant of the Program