libgo/go/syscall/errstr.go

   1 // errstr.go -- Error strings.
   2
   3 // Copyright 2009 The Go Authors. All rights reserved.
   4 // Use of this source code is governed by a BSD-style
   5 // license that can be found in the LICENSE file.
   6
   7 // +build !hurd
   8 // +build !linux
   9
  10 package syscall
  11
  12 //sysnb strerror_r(errnum int, buf []byte) (err Errno)
  13 //strerror_r(errnum _C_int, buf *byte, buflen Size_t) _C_int
  14
  15 func Errstr(errnum int) string {
  16         for len := 128; ; len *= 2 {
  17                 b := make([]byte, len)
  18                 errno := strerror_r(errnum, b)
  19                 if errno == 0 {
  20                         i := 0
  21                         for b[i] != 0 {
  22                                 i++
  23                         }
  24                         // Lowercase first letter: Bad -> bad, but
  25                         // STREAM -> STREAM.
  26                         if i > 1 && 'A' <= b[0] && b[0] <= 'Z' && 'a' <= b[1] && b[1] <= 'z' {
  27                                 b[0] += 'a' - 'A'
  28                         }
  29                         return string(b[:i])
  30                 }
  31                 if errno != ERANGE {
  32                         return "errstr failure"
  33                 }
  34         }
  35 }