kaguya
32 lines
873 B
C
32 lines
873 B
C
#include <assert.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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static const char *arr[] = { "xyz", "abc", "ghi", "def" };
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static const size_t magic = 0xDEADBEEF;
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static int cmpstringp(const void *p1, const void *p2, void *ctx) {
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/* The actual arguments to this function are "pointers to
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* pointers to char", but strcmp(3) arguments are "pointers
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* to char", hence the following cast plus dereference. */
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assert(*(size_t *) ctx == magic);
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return strcmp(*(const char **) p1, *(const char **) p2);
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}
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int main() {
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qsort_r(&arr[0], sizeof(arr) / sizeof(*arr), sizeof(char *), cmpstringp, (void *) &magic);
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assert(!strcmp(arr[0], "abc"));
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assert(!strcmp(arr[1], "def"));
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assert(!strcmp(arr[2], "ghi"));
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assert(!strcmp(arr[3], "xyz"));
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for(size_t i = 0; i < sizeof(arr) / sizeof(*arr); i++) {
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fprintf(stderr, "%s\n", arr[i]);
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}
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return 0;
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}
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