c_ch01_ex22.c

/*Exercise 1-22. Write a program to ``fold'' long input lines into two or more shorter lines after the last non-blank character *that occurs before the n-th column of input. Make sure your program does something intelligent with very long lines, and if there are no blanks or tabs before the specified column.*/
#include <stdio.h>
#define MAX     1000
char str[MAX];
int fold(int len);
int main()
{
        int len;
        while ((len = fold(MAX)) > 0)
                printf("%s\n", str);
        return 0;
}
int fold(int len) {
        int c, i, lc;
        i = lc = 0;
        while ((c = getchar()) != EOF && c != '\n' && i < len - 1 ) {
                lc++;
                if (lc >= 40) {
                        if (c != ' ' && c != '.' && c != ',' && c != ';' && c != '(')
                                str[i++] = '-';
                        str[i++] = '\n';
                        lc = 0;
                }
                str[i++] = c;
        }
        str[i] = '\0';
        return i;
}