问为什么使用4096个元素作为char数组缓冲区？

EN

int main(int argc, char **argv) {
    if (argc != 2) {
        fprintf(stderr, "Usage: %s <PATTERN>\n", argv[0]);
        return 2;
    }

    /* we're not going to worry about long lines */
    char buf[4096]; // 4kibi

    while (!feof(stdin) && !ferror(stdin)) { // when given a file through input redirection, file becomes stdin
        if (!fgets(buf, sizeof(buf), stdin)) { // puts reads sizeof(buf) characters from stdin and puts it into buf; fgets() stops reading when the newline is read
            break;
        }
        if (rgrep_matches(buf, argv[1])) {
            fputs(buf, stdout); // writes the string into stdout
            fflush(stdout);
        }
    }

    if (ferror(stdin)) {
        perror(argv[0]); // interprets error
        return 1;
    }

    return 0;
}