Function visctrl

src/hacklib.c:468–493

make a displayable string from a character */

#define VISCTRL_NBUF 5
/* make a displayable string from a character */
char *
visctrl(char c)
{
    static char visctrl_bufs[VISCTRL_NBUF][5];
    static int nbuf = 0;
    int i = 0;
    char *ccc = visctrl_bufs[nbuf];
    nbuf = (nbuf + 1) % VISCTRL_NBUF;

    if ((uchar) c & 0200) {
        ccc[i++] = 'M';
        ccc[i++] = '-';
    }
    c &= 0177;
    if (c < 040) {
        ccc[i++] = '^';
        ccc[i++] = c | 0100; /* letter */
    } else if (c == 0177) {
        ccc[i++] = '^';
        ccc[i++] = c & ~0100; /* '?' */
    } else {
        ccc[i++] = c; /* printable character */
    }
    ccc[i] = '\0';
    return ccc;
}

/* strip all the chars in stuff_to_strip from orig */
/* caller is responsible for ensuring that bp is a