Task: Just in time processing on a character stream
C: #include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>

struct UserInput {
    char formFeed;
    char lineFeed;
    char tab;
    char space;
};

struct UserInputNode {
    struct UserInput ui;
    struct UserInputNode *next;
};

bool decode(FILE *fp, const struct UserInput ui) {
    char f = 0, l = 0, t = 0, s = 0;
    char buffer[1];

    while (fread(buffer, 1, 1, fp)) {
        char c = buffer[0];

        if (f == ui.formFeed && l == ui.lineFeed && t == ui.tab && s == ui.space) {
            if (c == '!')
                return false;
            putchar(c);
            return true;
        } else if (c == '\f') {
            f++;
            l = t = s = 0;
        } else if (c == '\n') {
            l++;
            t = s = 0;
        } else if (c == '\t') {
            t++;
            s = 0;
        } else {
            s++;
        }
    }

    return false;
}

void decodeFile(char *fileName, struct UserInputNode *uin) {
    FILE *fp;

    fp = fopen(fileName, "r");
    if (NULL == fp) {
        fprintf(stderr, "Could not find %s\n", fileName);
        return;
    }

    if (NULL == uin) {
        fprintf(stderr, "No user input detected!\n");
        return;
    }

    while (NULL != uin) {
        if (!decode(fp, uin->ui)) {
            break;
        }
        fseek(fp, 0, SEEK_SET);
        uin = uin->next;
    }
    printf("\n\n");
}

struct UserInputNode *getUserInput() {
    struct UserInputNode *uip, *temp;

    
    temp = malloc(sizeof(struct UserInputNode));
    temp->ui.formFeed = 0;
    temp->ui.lineFeed = 18;
    temp->ui.tab = 0;
    temp->ui.space = 0;
    uip = temp;

    
    temp->next = malloc(sizeof(struct UserInputNode));
    temp = temp->next;
    temp->ui.formFeed = 0;
    temp->ui.lineFeed = 68;
    temp->ui.tab = 0;
    temp->ui.space = 1;

    
    temp->next = malloc(sizeof(struct UserInputNode));
    temp = temp->next;
    temp->ui.formFeed = 0;
    temp->ui.lineFeed = 100;
    temp->ui.tab = 0;
    temp->ui.space = 32;

    
    temp->next = malloc(sizeof(struct UserInputNode));
    temp = temp->next;
    temp->ui.formFeed = 0;
    temp->ui.lineFeed = 114;
    temp->ui.tab = 0;
    temp->ui.space = 45;

    
    temp->next = malloc(sizeof(struct UserInputNode));
    temp = temp->next;
    temp->ui.formFeed = 0;
    temp->ui.lineFeed = 38;
    temp->ui.tab = 0;
    temp->ui.space = 26;

    
    temp->next = malloc(sizeof(struct UserInputNode));
    temp = temp->next;
    temp->ui.formFeed = 0;
    temp->ui.lineFeed = 16;
    temp->ui.tab = 0;
    temp->ui.space = 21;

    
    temp->next = malloc(sizeof(struct UserInputNode));
    temp = temp->next;
    temp->ui.formFeed = 0;
    temp->ui.lineFeed = 17;
    temp->ui.tab = 0;
    temp->ui.space = 59;

    
    temp->next = malloc(sizeof(struct UserInputNode));
    temp = temp->next;
    temp->ui.formFeed = 0;
    temp->ui.lineFeed = 11;
    temp->ui.tab = 0;
    temp->ui.space = 29;

    
    temp->next = malloc(sizeof(struct UserInputNode));
    temp = temp->next;
    temp->ui.formFeed = 0;
    temp->ui.lineFeed = 102;
    temp->ui.tab = 0;
    temp->ui.space = 0;

    
    temp->next = malloc(sizeof(struct UserInputNode));
    temp = temp->next;
    temp->ui.formFeed = 0;
    temp->ui.lineFeed = 10;
    temp->ui.tab = 0;
    temp->ui.space = 50;

    
    temp->next = malloc(sizeof(struct UserInputNode));
    temp = temp->next;
    temp->ui.formFeed = 0;
    temp->ui.lineFeed = 39;
    temp->ui.tab = 0;
    temp->ui.space = 42;

    
    temp->next = malloc(sizeof(struct UserInputNode));
    temp = temp->next;
    temp->ui.formFeed = 0;
    temp->ui.lineFeed = 33;
    temp->ui.tab = 0;
    temp->ui.space = 50;

    
    temp->next = malloc(sizeof(struct UserInputNode));
    temp = temp->next;
    temp->ui.formFeed = 0;
    temp->ui.lineFeed = 46;
    temp->ui.tab = 0;
    temp->ui.space = 54;

    
    temp->next = malloc(sizeof(struct UserInputNode));
    temp = temp->next;
    temp->ui.formFeed = 0;
    temp->ui.lineFeed = 76;
    temp->ui.tab = 0;
    temp->ui.space = 47;

    
    temp->next = malloc(sizeof(struct UserInputNode));
    temp = temp->next;
    temp->ui.formFeed = 0;
    temp->ui.lineFeed = 84;
    temp->ui.tab = 2;
    temp->ui.space = 28;

    temp->next = NULL;
    return uip;
}

void freeUserInput(struct UserInputNode *uip) {
    if (NULL == uip) {
        return;
    }

    freeUserInput(uip->next);
    uip->next = NULL;

    free(uip);
}

int main() {
    struct UserInputNode *uip;

    uip = getUserInput();
    decodeFile("theRaven.txt", uip);
    freeUserInput(uip);

    return 0;
}

Python: import sys

class UserInput:
    def __init__(self,chunk):
        self.formFeed = int(chunk[0])
        self.lineFeed = int(chunk[1])
        self.tab = int(chunk[2])
        self.space = int(chunk[3])

    def __str__(self):
        return "(ff=%d; lf=%d; tb=%d; sp%d)" % (self.formFeed,self.lineFeed,self.tab,self.space)

def chunks(l,n):
    for i in xrange(0, len(l), n):
        yield l[i:i+n]

def getUserInput():
    h = "0 18 0 0 0 68 0 1 0 100 0 32 0 114 0 45 0 38 0 26 0 16 0 21 0 17 0 59 0 11 "\
        "0 29 0 102 0 0 0 10 0 50 0 39 0 42 0 33 0 50 0 46 0 54 0 76 0 47 0 84 2 28"
    ha = h.split()
    return [UserInput(chunk) for chunk in chunks(ha, 4)]

def decode(filename,uiList):
    f = open(filename, "r")
    text = f.read()

    def decode2(ui):
        f = 0
        l = 0
        t = 0
        s = 0
        for c in text:
            if f == ui.formFeed and l == ui.lineFeed and t == ui.tab and s == ui.space:
                if c == '!':
                    return False
                sys.stdout.write(c)
                return True
            if c == '\u000c':
                f=f+1
                l=0
                t=0
                s=0
            elif c == '\n':
                l=l+1
                t=0
                s=0
            elif c == '\t':
                t=t+1
                s=0
            else:
                s=s+1
        return False

    for ui in uiList:
        if not decode2(ui):
            break
    print



uiList = getUserInput()
decode("theRaven.txt", uiList)