libgo/go/syscall/errstr_linux.go

   1 // errstr_linux.go -- GNU/Linux specific error strings.
   2
   3 // Copyright 2010 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 // We use this rather than errstr.go because on GNU/Linux sterror_r
   8 // returns a pointer to the error message, and may not use buf at all.
   9
  10 package syscall
  11
  12 import "unsafe"
  13
  14 //sysnb strerror_r(errnum int, b []byte) (errstr *byte)
  15 //strerror_r(errnum _C_int, b *byte, len Size_t) *byte
  16
  17 func Errstr(errnum int) string {
  18         a := make([]byte, 128)
  19         p := strerror_r(errnum, a)
  20         b := (*[1000]byte)(unsafe.Pointer(p))
  21         i := 0
  22         for b[i] != 0 {
  23                 i++
  24         }
  25         // Lowercase first letter: Bad -> bad, but STREAM -> STREAM.
  26         if i > 1 && 'A' <= b[0] && b[0] <= 'Z' && 'a' <= b[1] && b[1] <= 'z' {
  27                 c := b[0] + 'a' - 'A'
  28                 return string(c) + string(b[1:i])
  29         }
  30         return string(b[:i])
  31 }