How to delete everything after matching string in R?

Question

I have a vector of strings like this

test <- c("Dcl2_SsHV2L_2_CAAAAG_L003_R1_001", "Dcl2_SsHV2L_2_CAAAAG_L003_R1_001", 
"Dcl2_SsHV2L_2_CAAAAG_L003_R1_001", "Dcl1_SsHV2L_2_GGTAGC_L003_R1_001")

I need to delete everything after "SsHV2L" and get only

Dcl2_SsHV2L
Dcl2_SsHV2L
Dcl2_SsHV2L
Dcl1_SsHV2L

I tried: gsub("SsHV2L.*","",test)

what is the proper way of doing it?

@nicola `Error in gsub("(?<=SsHV2L).*", "", test) : invalid regular expression '(?<=SsHV2L).*', reason 'Invalid regexp'` — MAPK, Nov 27 '18 at 15:49

score 3 · Accepted Answer · answered Nov 27 '18 at 15:51

3

You can just do

gsub("SsHV2L.+$", "SsHV2L", test)

Here you grab the "SsHV2L" where there is something after it and then just replace all of that with only "SsHV2L"

answered Nov 27 '18 at 15:51

MrFlick

195,160
17
277
295

score 1 · Answer 2 · answered Nov 27 '18 at 15:56

1

gsub("(^.+SsHV2L)(.+$)","\\1", test)
[1] "Dcl2_SsHV2L" "Dcl2_SsHV2L" "Dcl2_SsHV2L" "Dcl1_SsHV2L"

This uses a pattern that has two capture classes, the first on end in hte target string and then only that capture class is kept.

answered Nov 27 '18 at 15:56

IRTFM

258,963
21
364
487

How to delete everything after matching string in R?

2 Answers2

Linked