Remove all text between two brackets

With this:

gsub("\\[[^\\]]*\\]", "", subject, perl=TRUE);

What the regex means:

  \[                       # '['
  [^\]]*                   # any character except: '\]' (0 or more
                           # times (matching the most amount possible))
  \]                       # ']'

The following should do the trick. The ? forces a lazy match, which matches as few . as possible before the subsequent ].

gsub('\\[.*?\\]', '', text)

Here'a another approach:

library(qdap)
bracketX(text, "square")