walloftext.c

/*
 * walloftext.c
 *
 * This is a hacky program to produce a paragraph of random text with
 * parts of a quote highlighted and spaced through it.
 * Don't judge, I didn't spend long on this.
 *
 * Usage:
 * ./walloftext [file]
 * where [file] contains the quote, with each section on a new line
 *
 * Spacing of the text is randomized and may not always look good.
 * Pressing 'r' (or resizing the window) while it is running re positions everything.
 * Pressing Escape is the only way to exit.
 *
 * Compiling
 * $ cc walloftext.c -o walloftext -lncurses
 */

#include <stdio.h>
#include <stdlib.h>
#include <ncurses.h>
#include <time.h>

typedef struct {
    int position;
    char *str;
    int strlen;
} Line;

int linec = 0;
Line **lines = NULL;

void newline() {
    lines = realloc(lines, (linec+1)*sizeof(Line*));
    lines[linec] = calloc(1, sizeof(Line));
    linec++;
}

void lineappend(char c) {
    lines[linec-1]->str = realloc(lines[linec-1]->str, (lines[linec-1]->strlen+2)*sizeof(char));
    lines[linec-1]->str[lines[linec-1]->strlen] = c;
    lines[linec-1]->str[lines[linec-1]->strlen+1] = '\0';
    lines[linec-1]->strlen++;
}

void freelines() {
    for (int i = 0; i < linec; i++) {
        free(lines[i]->str);
        free(lines[i]);
    }
    free(lines);
}

void printline(int i) {
    printf("%d = {position = %d, str = %s, strlen = %d}\n", i, lines[i]->position, lines[i]->str, lines[i]->strlen);
}

void drawwall() {
    for (int i = 0; i < linec; i++) {
        //Decides where each line will go. Maintains order. Tries to stop line wrapping.
        do {
            lines[i]->position = (i*LINES*COLS/linec)+rand()%(LINES*COLS/linec);
        } while (lines[i]->position%COLS + lines[i]->strlen + 2 > COLS && lines[i]->strlen + 2 <= COLS); //Choose a new position until " str " doesn't wrap over
    }

    attron(A_BOLD); // Bold colors are better

    int online = 0; //on which line (not connected to internet)
    for (int i = 0; i < LINES*COLS; i++) { //loop through every character
        if (online < linec && i >= lines[online]->position) { //If there is another line and we are at its position
            attron(COLOR_PAIR(2)); //Make it blue
            printw(" %s ", lines[online]->str); //Print string remember trailing spaces
            i += lines[online]->strlen; //Line is more than one character need to inc count
            online++; //next line
            attroff(COLOR_PAIR(2)); //reset colors
        }
        else {
            attron(COLOR_PAIR(1)); //make it grey
            if (rand()%5) { // 1 in 5 chance of being a space, otherwise lowercase char
                printw("%c", 97+rand()%26); // 97 to 97+26 is ascci for a-z
            }
            else {
                printw(" ");
            }
            attroff(COLOR_PAIR(1)); //reset colors
        }
    }
    refresh(); // !important
}

int main(int argc, char **argv) {

    //Need a file argument
    if (argc != 2) {
        printf("%s [file]\n", argv[0]);
        return 1;
    }

    //Open file, exit if fail
    FILE *input = fopen(argv[1], "r");
    if (!input) {
        printf("could not open %s\n", argv[1]);
        return 2;
    }

    //Populate the lines variable
    newline();

    //Read the file
    int c;
    while ((c = fgetc(input)) != EOF) {
        switch (c) {
            case '\n': //Newlines create new lines
                newline();
                break;
            default: //All other characters written in
                lineappend(c);
                break;
        }
    }
    //There is always a newline before the file ends, get rid of extra line
    linec--;
    free(lines[linec]->str);
    free(lines[linec]);
    lines = realloc(lines, (linec)*sizeof(Line));

    fclose(input);

    //Start ncurses
    //Don't want weird things happening like keystrokes or visible cursors
    initscr();
    noecho();
    curs_set(0);
    srand((unsigned int)time(NULL));

    //Init the colors. 1 for filler, 2 for text
    start_color();
    init_pair(1, COLOR_BLACK, COLOR_BLACK);
    init_pair(2, COLOR_CYAN, COLOR_BLACK);

    //Initial drawing
    drawwall();
    
    while ((c = getch()) != 27) { // Exit when they press escape
        switch (c) {
            // r and the window being resized draw a new wall of text
            case 'r':
            case KEY_RESIZE:
                erase();
                drawwall();
                break;
        }
    }

    //Close and free
    endwin();

    freelines();

}

this is great