My attempts, but without results !!!
How to join the patterns of the two independent grep, in one, and obtain the results
txt<-c("OAT","HST","OCT","OMT","CTT","CTT_OMT","OOT")
> grep(pattern = "^[OHC].T$", x = txt, value = TRUE)
[1] "OAT" "HST" "OCT" "OMT" "CTT" "OOT"
> #1
> txt2<-grep(pattern = "^[OHC].T$", x = txt, value = TRUE)
> grep(pattern = '[^"OOT"]', x = txt2, value = TRUE)
[1] "OAT" "HST" "OCT" "OMT" "CTT"
> #I would use two grep calls:
> #2
> grep("OOT", grep('^[OHC].T$', txt, value = T),value = T,invert=TRUE)
[1] "OAT" "HST" "OCT" "OMT" "CTT"
> #3
> grep('[^"OOT"]', grep('^[OHC].T$', txt, value = T),value = T)
[1] "OAT" "HST" "OCT" "OMT" "CTT"
> #4
> intersect(grep('^[OHC].T$',txt,value = T),grep("OOT",txt,invert=TRUE,value = T))
[1] "OAT" "HST" "OCT" "OMT" "CTT"
> ###without results !!!
> grep('[^\\bOOT]', txt,value = T)
[1] "OAT" "HST" "OCT" "OMT" "CTT" "CTT_OMT"
> grep('([^"OOT"].$)', txt,value = T)
[1] "OAT" "HST" "OCT" "OMT" "CTT_OMT"
>
> grep('^([?CM]|[^\\b_])*$', txt,value = T)
[1] "OAT" "HST" "OCT" "OMT" "CTT" "OOT"
>