# cat in Go


After spending every free minute to `Go` I'm starting to get a feel
for the language. Every one has to start somewhere, so I decided to 
"port" Unix utils to Go. I'm starting with `cat`, and thanks to 
the Go tutorial this is the result.

    package main

    // An implementation of Unix cat in Go

    import (
	    "os";
	    "fmt";
	    "flag";
    )

    func cat(filename string) bool {
	    const NBUF = 512;
	    var buf [NBUF]byte;
	    if f, e := os.Open(filename, os.O_RDONLY, 0); e != nil {
		    fmt.Fprintf(os.Stderr, "cat: error reading from %s: %s\n",
			    filename, e.String());
		    return true;
	    } else {
		    for {
			    switch nr, _ := f.Read(&buf); true {
			    case nr < 0:
				    os.Exit(1)
			    case nr == 0:	// EOF
				    return true
			    case nr > 0:
				    if nw, ew := os.Stdout.Write(buf[0:nr]); nw != nr {
					    fmt.Fprintf(os.Stderr,
						    "cat: error writing from %s: %s\n",
						    filename, ew.String());
					    return false;
				    }
			    }
		    }
	    }
	    return true;
    }

    func main() {
	    flag.Parse();	// implement -n TODO
	    if flag.NArg() == 0 {
		    cat("/dev/stdin")
	    }
	    for i := 0; i < flag.NArg(); i++ {
		    if !cat(flag.Arg(i)) {
			    os.Exit(1)
		    }
	    }
    }

In something like 50 lines you have a `cat` program. I'm really starting 
to like Go. Next up: extra features and a `grep` command.