[SOLVED] Delete all text after a specific occurrence in a string using bash

Issue

I have a sequence:

MALYYDHQIEAPDAAGSPSFISWHPVHPFLAVAYISTTSTGSVDIYLEQGECVPDTHVERPFRVASLCWHPTRLVLAVGWETGEVTVFNKQDKEQHTMPLTHTADITVLRWSPSGNCLLSGDRLGVLLLWRLDQRGRVQGTPLLKHEYGKHLTHCIFRLPPPGEDLVQLAKAAVSGDEKALDMFNWKKSSSGSLLKMGSHEGLLFFVSLMDGTVHYVDEKGKTTQVVSADSTIQMLFYMEKREALVVVTENLRLSLYTVPPEGKAEEVMKVKLSGKTGRRADIALIEGSLLVMAVGEAALRFWDIERGENYILSPDEKFGFEKGENMNCVCYCKVKGLLAAGTDRGRVAMWRKVPDFLGSPGAEGKDRWALQTPTELQGNITQIQWGSRKNLLAVNSVISVAILSERAMSSHFHQQVAAMQVSPSLLNVCFLSTGVAHSLRTDMHISGVFATKDAVAVWNGRQVAIFELSGAAIRSAGTFLCETPVLAMHEENVYTVESNRVQVRTWQGTVKQLLLFSETEGNPCFLDICGNFLVVGTDLAHFKSFDLSRREAKAHCSCRSLAELVPGVGGIASLRCSSSGSTISILPSKADNSPDSKICFYDVEMDTVTVFDFKTGQIDRRETLSFNEQETNKSHLFVDEGLKNYVPVNHFWDQSEPRLFVCEAVQETPRSQPQSANGQPQDGRAGPAADVLILSFFISEEHGFLLHESFPRPATSHSLLGMEVPYYYFTRKPEEADREDEVEPGCHHIPQMVSRRPLRDFVGLEDCDKATRDAMLHFSFFVTIGDMDEAFKSIKLIKSEAVWENMARMCVKTQRLDVAKVCLGNMGHARGARALREAEQEPELEARVAVLATQLGMLEDAEQLYRKCKRHDLLNKFYQAAGRWQEALQVAEHHDRVHLRSTYHRYAGHLEASADCSRALSYYEKSDTHRFEVPRMLSEDLPSLELYVNKMKDKTLWRWWAQYLESQGEMDAALHYYELARDHFSLVRIHCFQGNVQKAAQIANETGNLAASYHLARQYESQEEVGQAVHFYTRAQAFKNAIRLCKENGLDDQLMNLALLSSPEDMIEAARYYEEKGVQMDRAVMLYHKAGHFSKALELAFATQQFVALQLIAEDLDETSDPALLARCSDFFIEHSQYERAVELLLAARKYQEALQLCLGQNMSITEEMAEKMTVAKDSSDLPEESRRELLEQIADCCMRQGSYHLATKKYTQAGNKLKAMRALLKSGDTEKITFFASVSRQKEIYIMAANYLQSLDWRKEPEIMKNIIGFYTKGRALDLLAGFYDACAQVEIDEYQNYDKAHGALTEAYKCLAKAKAKSPLDQETRLAQLQSRMALVKRFIQARRTYTEDPKESIKQCELLLEEPDLDSTIRIGDVYGFLVEHYVRKEEYQTAYRFLEEMRRRLPLANMSYYVSPQAVDAVHRGLGLPLPRTVPEQVRHNSMEDARELDEEVVEEADDDP

I would like to replace index position 383 (Q) with nothing after it, so the desired outcome would be:

MALYYDHQIEAPDAAGSPSFISWHPVHPFLAVAYISTTSTGSVDIYLEQGECVPDTHVERPFRVASLCWHPTRLVLAVGWETGEVTVFNKQDKEQHTMPLTHTADITVLRWSPSGNCLLSGDRLGVLLLWRLDQRGRVQGTPLLKHEYGKHLTHCIFRLPPPGEDLVQLAKAAVSGDEKALDMFNWKKSSSGSLLKMGSHEGLLFFVSLMDGTVHYVDEKGKTTQVVSADSTIQMLFYMEKREALVVVTENLRLSLYTVPPEGKAEEVMKVKLSGKTGRRADIALIEGSLLVMAVGEAALRFWDIERGENYILSPDEKFGFEKGENMNCVCYCKVKGLLAAGTDRGRVAMWRKVPDFLGSPGAEGKDRWALQTPTELQGNITQ

I have tried:

sed 's/"Q"//383' text.file
sed 's/Q//383' text.file

But that does not do anything.

In the long term I need to do with with a few other positions so a method that is flexible would be much appreciated.

All the best

Solution

This might work for you (GNU sed):

sed -zEi 's/(.{383}).*/\1/' file

Store the first 383 characters as a back reference and remove the rest.

N.B. the -z option slurps the entire file into memory.

Answered By - potong