[R] grep

[Steven Yen]

Below, the first command simply creates a list of 16 names (labels) 
which can be ignore.

In the 2nd and 3rd commands, I am able to identify names containing "black".

In line 4, I am trying to identify names containing "black" or "conserv" 
but obviously it does not work. Can someone help? Thanks.

 > names<-names(tp.nohs$estimate)[c(1:8,58:65)]; names
  [1] "x1.one"      "x1.black"    "x1.othrrace" "x1.moddkna" 
"x1.conserv"  "x1.nstrprty"
  [7] "x1.strrep"   "x1.sevngprt" "x2.one"      "x2.black" "x2.othrrace" 
"x2.moddkna"
[13] "x2.conserv"  "x2.nstrprty" "x2.strrep"   "x2.sevngprt"
 > grep("black",names,value=TRUE)
[1] "x1.black" "x2.black"
 > grep("black",names,value=FALSE)
[1]  2 10
 > grep(c("black","conserv"),names,value=TRUE)
[1] "x1.black" "x2.black"
Warning message:
In grep(c("black", "conserv"), names, value = TRUE) :
   argument 'pattern' has length > 1 and only the first element will be used