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  1. a <- c("abcxyz", "abcdef", "defxyz", "abcdefxyz", "xyzdefabc")
  2. grep("^(?=.*abc)(?=.*xyz)", a, ignore.case=TRUE, perl=TRUE)
Success #stdin #stdout 0.23s 60752KB
stdin
Standard input is empty
stdout
[1] 1 4 5