Regexpression - how to find subgroups in strings

Question

I have

[1] "000010004" "011120000" "002030000" "000300020" "003000020" "001000040" "000030020" "000010112"

[9] "050000000" "000000041" "001020020" "001030001" "001000130" "000000050" "000120020" "000500000"

using grep I want to find all groups (string inside "" is a group) that contain

a. subgroup 2,3 (means: ...2...3... and ...3...2...)

b. subgroup 1, 1, 1, 2 (means: ...1...1...1...2 and 1...1...2...1... etc etc)

Order doesnt matter, but frequency does. Meaning for a) 2 and 3 each should just appear once.

thanks for help

Answer 1

This can be done with a regular expression using lookahead but isn't really pretty:

For example to match a quoted number that contains exactly one 2 and one 3 you could do this (verbose regex used for readability):

"         # quote
(?=       # Assert that the following can be matched:
 [^\D2]*  # zero or more numbers except 2
 2        # 2
 [^\D2]*  # zero or more numbers except 2
 "        # quote
)         # End of lookahead
(?=[^\D3]*3[^\D3]*") # same for the number 3
(\d+)     # one or more digits, capture the result
"         # quote

To match exactly three 1s and one 2:

"         # quote
(?=       # Assert that the following can be matched:
 (?:      # Match the following group:
  [^\D1]* # zero or more numbers except 1
  1       # 1
 ){3}     # exactly three times.
 [^\D1]*  # Match zero or more numbers except 1
 "        # quote
)         # End of lookahead
(?=[^\D2]*2[^\D2]*") # as above
(\d+)     # one or more digits, capture the result
"         # quote

I don't know if this will work with standard grep.

Answer 2

I assume with a. numbers 2,3 you want to match following entries of the input array

[3] "002030000"
[4] "000300020"
[5] "003000020"
[7] "000030020"

and with b. numbers 1, 1, 1,2 you want to match following entries

[2] "011120000"
[8] "000010112"

to check for frequency you'd probably need some regex with lookaround. This is rather complicated if possible at all.

Answer 3

First of all it's not possible with grep alone.

But you may do the following:

1. Find all groups (quoted things)
2. Make sets out of them
3. Compare your input against these sets.

It's trivial in awk.