the items to write to stdout
In case of an I/O error, throws an StdioException.
Reads stdin and writes it to stdout with an argument counter.
import std.stdio; void main() { string line; for (size_t count = 0; (line = readln) !is null; count++) { writeln("Input ", count, ": ", line); } }
Equivalent to write(args, '\n'). Calling writeln without arguments is valid and just prints a newline to the standard output.