str_error_r.c 1.0 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. #undef _GNU_SOURCE
  3. #include <string.h>
  4. #include <stdio.h>
  5. #include <linux/string.h>
  6. /*
  7. * The tools so far have been using the strerror_r() GNU variant, that returns
  8. * a string, be it the buffer passed or something else.
  9. *
  10. * But that, besides being tricky in cases where we expect that the function
  11. * using strerror_r() returns the error formatted in a provided buffer (we have
  12. * to check if it returned something else and copy that instead), breaks the
  13. * build on systems not using glibc, like Alpine Linux, where musl libc is
  14. * used.
  15. *
  16. * So, introduce yet another wrapper, str_error_r(), that has the GNU
  17. * interface, but uses the portable XSI variant of strerror_r(), so that users
  18. * rest asured that the provided buffer is used and it is what is returned.
  19. */
  20. char *str_error_r(int errnum, char *buf, size_t buflen)
  21. {
  22. int err = strerror_r(errnum, buf, buflen);
  23. if (err)
  24. snprintf(buf, buflen, "INTERNAL ERROR: strerror_r(%d, [buf], %zd)=%d", errnum, buflen, err);
  25. return buf;
  26. }