#include <stdlib.h>
#include <stdio.h>
 
void tailString(char *in, char *out) {
    memcpy(out, &in[1], 256);
}
 
int main() {
    printf("Введите исходную строку: ");
    char a[256];
    if (!fgets(a, sizeof(a), stdin)) {
        printf("Ошибка ввода.\n");
        exit(EXIT_FAILURE);
    };
    char b[sizeof(a)/ sizeof(*a)];
    tailString(a, b);
    printf("Новая строка: %s\n", b);
    return 0;
}

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

dGVzdCBzdHJpbmcgdGVzdA==

test string test