1 extern crate memmap2; 2 3 use std::env; 4 use std::fs::File; 5 use std::io::{self, Write}; 6 7 use memmap2::Mmap; 8 9 /// Output a file's contents to stdout. The file path must be provided as the first process 10 /// argument. main()11fn main() { 12 let path = env::args() 13 .nth(1) 14 .expect("supply a single path as the program argument"); 15 16 let file = File::open(path).expect("failed to open the file"); 17 18 let mmap = unsafe { Mmap::map(&file).expect("failed to map the file") }; 19 20 io::stdout() 21 .write_all(&mmap[..]) 22 .expect("failed to output the file contents"); 23 } 24