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copied!<p>Here is the correct way to do it, it is a little longer than the simplest way but it doesn't suffer from undefined behavior if the value read is out of range, works properly if the first character is not a dot, etc. You didn't specify whether the numbers could be negative so I used a signed type but only allow positive values, you can easily change this by allowing the negative sign at the top of the inner while loop. This version allows any non-digit characters to delimit integers, if you only want dots to be allowed you can modify the inner loop to skip only dots and then check for a digit.</p> <pre><code>#include <stdio.h> #include <stdlib.h> #include <ctype.h> #include <errno.h> #define ARRAY_SIZE 10 size_t store_numbers (const char *s, long *array, size_t elems) { /* Scan string s, returning the number of integers found, delimited by * non-digit characters. If array is not null, store the first elems * numbers into the provided array */ long value; char *endptr; size_t index = 0; while (*s) { /* Skip any non-digits, add '-' to support negative numbers */ while (!isdigit(*s) && *s != '\0') s++; /* Try to read a number with strtol, set errno to 0 first as * we need it to detect a range error. */ errno = 0; value = strtol(s, &endptr, 10); if (s == endptr) break; /* Conversion failed, end of input */ if (errno != 0) { /* Error handling for out of range values here */ } /* Store value if array is not null and index is within array bounds */ if (array && index < elems) array[index] = value; index++; /* Update s to point to the first character not processed by strtol */ s = endptr; } /* Return the number of numbers found which may be more than were stored */ return index; } void print_numbers (const long *a, size_t elems) { size_t idx; for (idx = 0; idx < elems; idx++) printf("%ld\n", a[idx]); return; } int main (void) { size_t found, stored; long numbers[ARRAY_SIZE]; found = store_numbers("..1....10..20....30...40....50...80...", numbers, ARRAY_SIZE); if (found > ARRAY_SIZE) stored = ARRAY_SIZE; else stored = found; printf("Found %zu numbers, stored %zu numbers:\n", found, stored); print_numbers(numbers, stored); return 0; } </code></pre>

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