1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 | #include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <assert.h>
#include "clog.h"
// BUGGY -- This version has 2 known flaws:
// ∙ Does not allocate space for '\0'.
// ∙ printf(…) (via log_str(…)) tries to access past the end of the buffer (block).
char* repeat(char char_to_repeat, int num_times_to_repeat) { // returns memory on HEAP
// Alocate a new string sufficient for 'num_times_to_repeat' chars and
// assign the address of the first character to 'ch_repeated_str'.
char* ch_repeated_str = malloc(num_times_to_repeat * sizeof(*ch_repeated_str));
for(int i = 0; i < num_times_to_repeat; i++) {
ch_repeated_str[i] = char_to_repeat; // copy one character
}
ch_repeated_str[num_times_to_repeat] = '\0'; // Write null terminator at end of string
// WARNING: This has one more BUG: We did not malloc(…) enough memory.
return ch_repeated_str;
}
int main(int argc, char* argv[]) {
char* s = repeat('*', 5);
log_str(s);
free(s);
// IMPORANT: Call free(…) on every block that was allocated by malloc(…).
// └─ Corollary: Number of calls to malloc(…) should equal number of calls to free(…).
return EXIT_SUCCESS;
}
// Autocomplete: Ctrl-P
/* vim: set tabstop=4 shiftwidth=4 fileencoding=utf-8 noexpandtab: */
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