[R] utilize the R to write something on txt file

[Abelian]

i have to utilize the R to report the simulation result by txt file.
However, i have to write some introduction and explanination before
the result.
For example, In the first part. the introduction is like below

      ===================
       === Data description ===
       ===================
       Input directory name:
       Output directory name:
       The number of study groups:
       Data format: (e.g., user-specified SNP panel or Affy
100K, ....)

how can i output those characteristic on txt file?
by the way,, there are variables follow with "Input directory name:"
"Output directory name:", "The number of study groups:" etc
Thanks a lot~~~