CODEWITHSUNDEEP
unixawkaixcut
Matias Araya
Matias Araya

Reputation: 111

How to cut ranges from end to start?

I need to change the order of a string in AIX, but with the command cut I can't do it

Ex: echo FT0215202301.xml | cut -b 7-10,5-6,3-4

Result: 02152023

Expected: 20230215

Upvotes: 6

Views: 158

Answers (4)

Daweo
Daweo

Reputation: 36725

Ex: echo FT0215202301.xml | cut -b 7-10,5-6,3-4

Result: 02152023

Expected: 20230215

Observe that your command preserved order, which is logical considering cut does

remove sections from each line of files

Therefore your task is beyond what cut can do, as this would require to rearrange elements. If you wish to use awk to work with characters you might set field separator (FS) to empty string and access 1st character using $1, 2nd character using $2, 3rd character using $3 and so on. In this case you might do

echo FT0215202301.xml | awk 'BEGIN{FS=""}{print $7$8$9$10$3$4$5$6}'

gives output

20230215

(tested in GNU Awk 5.1.0, I am unable to test in aixawk so please try it yourself and write if it does work)

Upvotes: 0

RavinderSingh13
RavinderSingh13

Reputation: 133730

With GNU awk match function and its capability of using capturing groups into an array, one could try following code. Using regex ^.{2}(.{4})(.{4}).{2}\.xml$ which creates 2 capturing groups and save values into array named arr. which we are using to print the values as per requirement.

echo FT0215202301.xml | 
awk '
match($0,/^.{2}(.{4})(.{4}).{2}\.xml$/,arr){
  print arr[2] arr[1]
}
'

Upvotes: 3

markp-fuso
markp-fuso

Reputation: 35256

A couple ideas using awk or sed:

$ echo FT0215202301.xml | awk '{print substr($1,7,4) substr($1,3,4)}'
20230215

$ echo FT0215202301.xml | sed -E 's/^..(....)(....).*/\2\1/'
20230215

Same solutions but using a here string to eliminate the subshell:

$ awk '{print substr($1,7,4) substr($1,3,4)}' <<< 'FT0215202301.xml'
20230215

$ sed -E 's/^..(....)(....).*/\2\1/' <<< 'FT0215202301.xml'
20230215

If the filename is stored in a variable then you can use bash's substring capability (${var:start:length}) and eliminate the need for other binaries (eg, awk, sed), eg:

$ fname=FT0215202301.xml
$ echo "${fname:6:4}${fname:2:4}"
20230215

NOTE: bash string indexing starts at position 0

While the above solutions generate OP's expected output of 20230215, OP's cut -b 7-10,5-6,3-4 would seem to indicate OP may want 20231502 as the expected output. If this is the case the modified commands would be:

$ awk '{print substr($1,7,4) substr($1,5,2) substr($1,3,2)}' <<< 'FT0215202301.xml'
20231502

$ sed -E 's/^..(..)(..)(....).*/\3\2\1/' <<< 'FT0215202301.xml'
20231502

$ fname=FT0215202301.xml
$ echo "${fname:6:4}${fname:4:2}${fname:2:2}"
20231502

Upvotes: 5

pmf
pmf

Reputation: 36391

I'd use Bash's substring expansion:

f=FT0215202301.xml; echo "${f:6:4}${f:2:2}${f:4:2}"

20230215

Upvotes: 4

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