c - fscanf format %[variable length]s

Question

This question already has answers here: question from:https://stackoverflow.com/questions/65641495/fscanf-format-variable-lengths

Answer 1

You can construct the format string with snprintf:

    int length = atoi(argv[0]);
    w[length + 1];
    char fmt[20];
    snprintf(fmt, sizeof fmt, "%%%ds", length);
    fscanf(f1, fmt, w);

Yet a simpler solution is to use a while loop:

    int length = atoi(argv[0]);
    w[length + 1];
    int c, i = 0;
    while (i <= length && (c = getchar()) != EOF) {
        if (isspace(c)) {
            ungetc(c, stdin);
            break;
        }
        w[i++] = c;
    }
    w[i] = '';