How to read lines from stdin (*in*) in clojure

Question

I am writing my first clojure program, and want to read lines from stdin.

When I try this:

(doall (map #(println %) (line-seq *in*)))

I get this exception:

Exception in thread "main" java.lang.ClassCastException: clojure.lang.LineNumberingPushbackReader cannot be cast to java.io.BufferedReader (test.clj:0)

I get the same results in version 1.0 and 1.1

So how do I convert *in* into a seq I can iterate over? I would have thought that this is common enough that *in* itself would be iterable, but that does not work either - if I try to use it directly I get:

java.lang.IllegalArgumentException: Don't know how to create ISeq from: clojure.lang.LineNumberingPushbackReader (NO_SOURCE_FILE:0)

Also, are there any examples of doing general file handling in clojure?

Answer 1

Try wrapping *in* in a java.io.BufferedReader:

(doall (map println
            (line-seq (java.io.BufferedReader. *in*))))

Note that line-seq is documented to require a BufferedReader as its source.