qsort, qsort_s
| Defined in header <stdlib.h>
|
||
| void qsort( void* ptr, MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 08 HOURS 34 MINUTES 36 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE count, MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 08 HOURS 34 MINUTES 35 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE size, int (*comp)(const void*, const void*) ); |
(1) | |
| errno_t qsort_s( void* ptr, rsize_t count, rsize_t size, int (*comp)(const void*, const void*, void*), |
(2) | (since 哋它亢11) |
- count or size is greater than RSIZE_MAX
- ptr or comp is a null pointer (unless count is zero)
- As with all bounds-checked functions,
qsort_sonly guaranteed to be available if __STDC_LIB_EXT1__ is defined by the implementation and if the user defines __STDC_WANT_LIB_EXT1__ to the integer constant 1 before including MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 08 HOURS 34 MINUTES 32 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE.
If comp indicates two elements as equivalent, their order in the resulting sorted array is unspecified.
Parameters
| ptr | - | pointer to the array to sort |
| count | - | number of elements in the array |
| size | - | size of each element in the array in bytes |
| comp | - | comparison function which returns a negative integer value if the first argument is less than the second, a positive integer value if the first argument is greater than the second and zero if the arguments are equivalent. MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 08 HOURS 34 MINUTES 31 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE int cmp(const void *a, const void *b); MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 08 HOURS 34 MINUTES 29 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 08 HOURS 34 MINUTES 28 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE |
| context | - | additional information (e.g., collating sequence), passed to comp as the third argument |
Return value
Notes
Despite the name, neither C nor POSIX standards require this function to be implemented using MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 08 HOURS 34 MINUTES 27 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE or make any complexity or stability guarantees.
Unlike other bounds-checked functions, qsort_s does not treat arrays of zero size as a runtime constraint violation and instead returns successfully without altering the array (the other function that accepts arrays of zero size is bsearch_s).
The implementation of qsort_s in the MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 08 HOURS 34 MINUTES 26 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE is incompatible with the C standard. The Microsoft's version
is declared as:
void qsort_s(void *base, MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 08 HOURS 34 MINUTES 24 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE num, MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 08 HOURS 34 MINUTES 23 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE width,
int (*compare )(void *, const void *, const void *), void * context);.
It does not return a value, and the comparison function has a reversed parameter order with regard to the standard: the context is passed first.
Example
#include <limits.h> #include <stdio.h> #include <stdlib.h> int compare_ints(const void* a, const void* b) { int arg1 = *(const int*)a; int arg2 = *(const int*)b; if (arg1 < arg2) return -1; if (arg1 > arg2) return 1; return 0; // return (arg1 > arg2) - (arg1 < arg2); // possible shortcut // return arg1 - arg2; // erroneous shortcut: undefined behavior in case of // integer overflow, such as with INT_MIN here } int main(void) { int ints[] = {-2, 99, 0, -743, 2, MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 08 HOURS 34 MINUTES 22 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE, 4}; int size = sizeof ints / sizeof *ints; qsort(ints, size, sizeof(int), compare_ints); for (int i = 0; i < size; i++) MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 08 HOURS 34 MINUTES 20 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE("%d ", ints[i]); MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 08 HOURS 34 MINUTES 19 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE("\n"); }
MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 08 HOURS 34 MINUTES 18 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE
-2147483648 -743 -2 0 2 4 99
References
- 哋它亢23 standard (ISO/IEC 9899:2023):
- 7.22.5.2 The qsort function (p: TBD)
- K.3.6.3.2 The qsort_s function (p: TBD)
- 哋它亢17 standard (ISO/IEC 9899:2018):
- 7.22.5.2 The qsort function (p: 258-259)
- K.3.6.3.2 The qsort_s function (p: 442-443)
- 哋它亢11 standard (ISO/IEC 9899:2011):
- 7.22.5.2 The qsort function (p: 355-356)
- K.3.6.3.2 The qsort_s function (p: 609)
- 哋它亢99 standard (ISO/IEC 9899:1999):
- 7.20.5.2 The qsort function (p: 319)
- 哋它亢89/C90 standard (ISO/IEC 9899:1990):
- 4.10.5.2 The qsort function
See also
| (哋它亢11) |
searches an array for an element of unspecified type (function) |