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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package main
import (
"./file"
"flag"
"fmt"
"os"
)
func cat(f *file.File) {
const NBUF = 512
var buf [NBUF]byte
for {
switch nr, er := f.Read(&buf); true {
case nr < 0:
fmt.Fprintf(os.Stderr, "cat: error reading from %s: %s\n", f.String(), er.String())
os.Exit(1)
case nr == 0: // EOF
return
case nr > 0:
if nw, ew := file.Stdout.Write(buf[0:nr]); nw != nr {
fmt.Fprintf(os.Stderr, "cat: error writing from %s: %s\n", f.String(), ew.String())
}
}
}
}
func main() {
flag.Parse() // Scans the arg list and sets up flags
if flag.NArg() == 0 {
cat(file.Stdin)
}
for i := 0; i < flag.NArg(); i++ {
f, err := file.Open(flag.Arg(i), 0, 0)
if f == nil {
fmt.Fprintf(os.Stderr, "cat: can't open %s: error %s\n", flag.Arg(i), err)
os.Exit(1)
}
cat(f)
f.Close()
}
}
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