regex - Find regular expression string and replace it in R -

the purpose tidy dataset cleaning variable names replications. typical example:

var.name <- "blue cat"  #"true" variable name 

is found in dataset following entries/replications:

char <- c("blue cat","blue cat blueing","blue cats",           "blue cat dog", "blue catts cat","blue cat cat") 

the ideal result of above replications renamed var.name, ie "blue cat". following grep(..) that:

char[grep(paste("blue cat", collapse="|"), char, value=f)] <- var.name 

the drawback of method 1 has manually search & enter char occurrences. ideal solution parse "blue cat" regular expression , replace string matched.

any ideas? much.

if need parse regular expression, suffice.

sub('.*blue cat.*', var.name, char) # [1] "blue cat" "blue cat" "blue cat" "blue cat" "blue cat" "blue cat"