Question

I’m trying to add some functionality to dunst, a small notification system. I’ve never really done anything in C, but I did manage to do basically what I want in a small file:

#include<stdio.h>
#include<string.h>

main()
{
    char str1[128];
    char str2[128];
    sprintf(str1,"Hello");
    sprintf(str2,"world!");

    printf("%s %s\n",str1,str2);
}

strcat changes the first string given, which isn’t what I want. In the program, it calculates width for the window by the text given, and I want to append some text(hidden) onto the notification message (cur_msg->msg).

Here’s what the code looks like:

#define MAX(a,b)                ((a) > (b) ? (a) : (b))

void
drawmsg(void) {
    int width, x, y, height, drawn_msg_count, i;
    unsigned int len = list_len(msgqueue);
    msg_queue_t *cur_msg = msgqueue;
    char hidden[128];
    int hidden_count = 0;
    int hidden_color_idx = NORM;
    dc->x = 0;
    dc->y = 0;
    dc->h = 0;
    /* a height of 0 doesn't make sense, so we define it as 1 */
    if(geometry.h == 0) {
        geometry.h = 1;
    }

    height = MIN(geometry.h, len);
    drawn_msg_count = height;
    hidden_count = len - height;
    hidden_count = indicate_hidden && hidden_count > 0 ? hidden_count : 0;
    sprintf(hidden, "(%d more)", hidden_count);
    if(hidden_count && !single_line)
        height++;

    if(geometry.mask & WidthValue) {
        if(geometry.w == 0) {
            width = 0;
            for(i = 0; i < height; i++){
                width = MAX(width, textw(dc, cur_msg->msg));
                if(hidden_count && !single_line)
                    width = MAX(width, textw(dc,("%s %s",cur_msg->msg,hidden)));
                cur_msg = cur_msg->next;
            }
        } else {
            width = geometry.w;
        }
    } else {
        width = scr.dim.w;
    }

    cur_msg = msgqueue;

    if(geometry.mask & XNegative) {
        x = (scr.dim.x + (scr.dim.w - width)) + geometry.x;
    } else {
        x = scr.dim.x + geometry.x;
    }

    if(geometry.mask & YNegative) {
        y = (scr.dim.h + geometry.y) - height*font_h;
    } else {
       y = 0 + geometry.y;
    }

    resizedc(dc, width, height*font_h);
    XResizeWindow(dc->dpy, win, width, height*font_h);
    drawrect(dc, 0, 0, width, height*font_h, True, colors[NORM]->BG);

    for(i = 0; i < drawn_msg_count; i++) {
        if(cur_msg->start == 0)
            cur_msg->start = now;

        drawrect(dc, 0, dc->y, width, font_h, True, cur_msg->colors->BG);
        if(hidden_count && single_line){
            drawtext(dc, ("%s %s",cur_msg->msg,hidden), cur_msg->colors);
        } else {
            drawtext(dc, cur_msg->msg, cur_msg->colors);
        }

        dc->y += font_h;
        hidden_color_idx = cur_msg->urgency;
        cur_msg = cur_msg->next;
    }

    if(hidden_count && !single_line) {
        drawrect(dc, 0, dc->y, width, font_h, True, colors[NORM]->BG);

        drawtext(dc, hidden, colors[hidden_color_idx]);
        dc->y += font_h;
    }


    XMoveWindow(dc->dpy, win, x, y);

    mapdc(dc, win, width, height*font_h);
}

This is using it as a comma operator from what I’m guessing, and I’d like to use it like printf does, to replace the %s with the strings :/

How do I make it do this properly? If I can get it I think I can get the changes I want to work.

Feel free to shorten the code up, I don’t know what I really need to keep in and what’s okay to remove if I want some help on this.

Answer 1

Did not really read through your code, but it did definitely sound like sprint to me.

int sprintf ( char * str, const char * format, ... ); basically printf for strings. Will take the format operators and throw it all together into str.

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