#Cache xsort and qsort sort.cc code
#Cache xsort and qsort sort.cc plus

When i try compile the code below, my computer crashed while return the strcmp in pstrcmp function. I have check the openMyfile function and it's working correctly. The openMyfile is a function to read in the text file and put in a pointer w. This page is part of release 4.04 of the Linux man-pages project. file and then sort out each word alphabetical order using qsort.

SEE ALSO sort(1), alphasort(3), strcmp(3), versionsort(3) Qsort(&argv, argc - 1, sizeof(char *), cmpstringp) Return strcmp(* (char * const *) p1, * (char * const *) p2)

#Cache xsort and qsort sort.cc plus

To char', hence the following cast plus dereference */ Pointers to char', but strcmp(3) arguments are 'pointers * The actual arguments to this function are 'pointers to To compare C strings, the comparison function can call strcmp(3), as shown in the exampleįor one example of use, see the example under bsearch(3).Īnother example is the following program, which sorts the strings given in its command-Ĭmpstringp(const void *p1, const void *p2) │ qsort(), qsort_r() │ Thread safety │ MT-Safe │ VERSIONS qsort_r() was added to glibc in version 2.8.įor an explanation of the terms used in this section, see attributes(7). >(An extreme example is a large array of random 0's and 1's) For such a file, you'd only need to count the number of zeros. The qsort() and qsort_r() functions return no value. >Solaris 2.5 qsort() library call to be closer to O(nn) than >O(nlogn) when the ratio of the size of the data set to the >of unique elements in the data set is high. Way, the comparison function does not need to use global variables to pass throughĪrbitrary arguments, and is therefore reentrant and safe to use in threads. A pointer is passed to the comparison function via arg. These two arguments are pointers, and type casted to const void. Then compares them and get the relative order between them. Therefore there must be a function in addition to strcmp that performs the explicit casts and then calls strcmp. This comparator function takes two arguments. Unlike C, C++ doesn't allow implicit cast from void to other pointer types as well as many other incorrect casts. In this function we have to pass the comparator function. The qsort_r() function is identical to qsort() except that the comparison function compar This is used to sort some array using quicksort technique. If two members compare as equal, their order in the sorted array is

If the first argument is considered to be respectively less than, equal to, or greater L2-Cache, der außerhalb des Prozessors liegt, der allerdings geringe Zugriffszeiten von etwa 10-12 ns aufweist. Da dieser sehr teuer ist, wird meist nur ein L1-Cache in der Größe von 16 - 32 KByte verwendet, der häufig noch in Befehls- und Daten-Cache unterteilt ist. The comparison function must return an integer less than, equal to, or greater than zero L1-Cache, der direkt im Prozessorkern untergebracht ist. Pointed to by compar, which is called with two arguments that point to the objects being The contents of the array are sorted in ascending order according to a comparison function The qsort() function sorts an array with nmemb elements of size size. The function must not modify the objects passed to it and must return consistent results when called for the same objects, regardless of their positions in the array.ĭespite the name, C++, C, and POSIX standards do not require this function to be implemented using quicksort or make any complexity or stability guarantees.SYNOPSIS #include void qsort(void * base, size_t nmemb, size_t size, int (* compar )(const void *, const void *)) void qsort_r(void * base, size_t nmemb, size_t size, int (* compar )(const void *, const void *, void *), void * arg ) įeature Test Macro Requirements for glibc (see feature_test_macros(7)): void qsort(void base, sizet nitems, sizet size, int (compar) (const void, const void)) Parameters base This is the pointer to the first element of the array to be sorted. Int cmp ( const void *a, const void *b ) Following is the declaration for qsort () function. The signature of the comparison function should be equivalent to the following: Size of each element in the array in bytesĬomparison 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.