gistfile1.txt

#include <stdio.h>
#define LINECOL 20 /* "fold" after this column */

int main()
{
    int c, i, j, lastchar;
    int str[LINECOL];
    for (i = 0; i <= LINECOL; i++)
        str[i] = 0;

    i = 0;
    lastchar = 19;

    while ((c = getchar()) != EOF)
    {
        if (i >= LINECOL)
        {
            str[i] = c;
            for (j = 0; j <= lastchar; j++)
                printf("%c", str[j]);
            printf("\n");
            i = -1;
        }
        else
        {
            str[i] = c;
            if (c != ' ' && c != '\t')
                lastchar = i;
        }
        ++i;
    }
    return 0;
}