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I am struggling to find a name for the the series that file permissions in unix are represented by.

The numbers which can add up to a unique sum and no other combination of numbers from that set can add up to that unique sum.

The numbers in series are 1,2,4,.....?

Mohd Abdul Mujib
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    Bitset, bitmask ("permissions bitset"). Each number in this series is represented with binary number which has only one bit set, other bits are zeroes. – gudok Dec 07 '16 at 07:34
  • @gudok, Thanks, just after writing this question, I did actually remember the term 'bitmask', but again the series of the numbers have to be present there in the first place to be able to use the bits that represent them, or am I missing something? – Mohd Abdul Mujib Dec 07 '16 at 07:36
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    Those numbers are consecutive powers of two, i.e. 2^0, 2^1, 2^2, 2^3... – el.pescado - нет войне Dec 07 '16 at 07:50
  • Ohh, I see, so the next following numbers would be ..8,16,32....Hmm sounds fair enough. Thanks guyz, for your efforts. – Mohd Abdul Mujib Dec 07 '16 at 08:42

1 Answers1

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So, Just to have an answer to my question, the CHMOD numbers are called Bitmask and they are basically binary numbers starting from 2 and proceeding with the power of 2 each time.

One thing useful about this series is that no two numbers from this series add up to any other number from this series.

Mohd Abdul Mujib
  • 13,071
  • 8
  • 64
  • 88