Add tee utility

cat.nim

@@ -3,6 +3,11 @@ import common
 
 proc main(files:seq[string]) =
     for file in files:
+        if file == "-":
+            var line = ""
+            while stdin.readLine(line):
+                echo line
+        else:
             var s = newFileStream(file, fmRead)
             while not s.atEnd:
                 write(stdout, s.readChar)

nimbase.nimble

@@ -8,6 +8,6 @@ requires      "nim >= 0.19.0"
 requires      "cligen >= 0.9.19"
 requires      "stint >= 0.0.1"
 
-bin           = @["add", "cat", "cp", "div", "echo", "factor", "false", "head", "mkdir", "mul", "seq", "sleep", "sub", "true", "yes"]
+bin           = @["add", "cat", "cp", "div", "echo", "factor", "false", "head", "mkdir", "mul", "seq", "sleep", "sub", "tee", "true", "yes"]
 
 binDir        = "bin"

tee.nim

@@ -0,0 +1,15 @@
+import cligen, os, streams
+import common
+
+proc main(files:seq[string]) =
+    var
+        fileStreams:seq[Stream]
+        line = ""
+    for file in files:
+        fileStreams.add(newFileStream(file, fmWrite))
+    while stdin.readLine(line):
+        echo line
+        for fStream in fileStreams:
+            writeLine(fStream, line)
+
+dispatch(main, version=("version", nimbaseVersion))