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scanf_s.c 2.0 kB

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  1. /**
  2. * Copyright 2020 Huawei Technologies Co., Ltd
  3. *
  4. * Licensed under the Apache License, Version 2.0 (the "License");
  5. * you may not use this file except in compliance with the License.
  6. * You may obtain a copy of the License at
  7. *
  8. * http://www.apache.org/licenses/LICENSE-2.0
  9. *
  10. * Unless required by applicable law or agreed to in writing, software
  11. * distributed under the License is distributed on an "AS IS" BASIS,
  12. * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13. * See the License for the specific language governing permissions and
  14. * limitations under the License.
  15. */
  16. #include "securec.h"
  17. /*
  18. * <FUNCTION DESCRIPTION>
  19. * The scanf_s function is equivalent to fscanf_s with the argument stdin interposed before the arguments to scanf_s
  20. * The scanf_s function reads data from the standard input stream stdin and
  21. * writes the data into the location that's given by argument. Each argument
  22. * must be a pointer to a variable of a type that corresponds to a type specifier
  23. * in format. If copying occurs between strings that overlap, the behavior is
  24. * undefined.
  25. *
  26. * <INPUT PARAMETERS>
  27. * format Format control string.
  28. * ... Optional arguments.
  29. *
  30. * <OUTPUT PARAMETERS>
  31. * ... The converted value stored in user assigned address
  32. *
  33. * <RETURN VALUE>
  34. * Returns the number of fields successfully converted and assigned;
  35. * the return value does not include fields that were read but not assigned.
  36. * A return value of 0 indicates that no fields were assigned.
  37. * return -1 if an error occurs.
  38. */
  39. int scanf_s(const char *format, ...)
  40. {
  41. int ret; /* If initialization causes e838 */
  42. va_list argList;
  43. va_start(argList, format);
  44. ret = vscanf_s(format, argList);
  45. va_end(argList);
  46. (void)argList; /* to clear e438 last value assigned not used , the compiler will optimize this code */
  47. return ret;
  48. }