strerror.c 1.4 KB

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  1. /* Copyright (C) 1991, 1993, 1994 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. The GNU C Library is free software; you can redistribute it and/or
  4. modify it under the terms of the GNU Library General Public License as
  5. published by the Free Software Foundation; either version 2 of the
  6. License, or (at your option) any later version.
  7. The GNU C Library is distributed in the hope that it will be useful,
  8. but WITHOUT ANY WARRANTY; without even the implied warranty of
  9. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10. Library General Public License for more details.
  11. You should have received a copy of the GNU Library General Public
  12. License along with the GNU C Library; see the file COPYING.LIB. If
  13. not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  14. Cambridge, MA 02139, USA. */
  15. #include <stdio.h>
  16. #include <string.h>
  17. #include <errno.h>
  18. extern char *itoa(int);
  19. /* Return a string descibing the errno code in ERRNUM.
  20. The storage is good only until the next call to strerror.
  21. Writing to the storage causes undefined behavior. */
  22. char *strerror(int err)
  23. {
  24. static char retbuf[80];
  25. if (sys_nerr) {
  26. if (err < 0 || err >= sys_nerr)
  27. goto unknown;
  28. strcpy(retbuf, sys_errlist[err]);
  29. return retbuf;
  30. }
  31. if (err <= 0)
  32. goto unknown;
  33. unknown:
  34. strcpy(retbuf, "Unknown Error: errno=");
  35. strcat(retbuf, (char *) itoa(err));
  36. return retbuf;
  37. }