simple_print.c

// Cobbled together from code found at:
// https://www.cairographics.org/documentation/using_the_postscript_surface/
// http://www.cs.rpi.edu/~moorthy/Courses/os98/Pgms/client.c

// Don't forget to set the hostname in setup_socket()! (line 70)

// Build with:
// gcc simple_print.c -l cairo -o simple_print

// Can be tested with:
// netcat -l -p 9100 | less

#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>

#include <cairo/cairo.h>
#include <cairo/cairo-ps.h>

#define PAGE_WIDTH 612
#define PAGE_HEIGHT 792
#define BORDER 50

void error(char *msg)
{
    perror(msg);
    exit(0);
}

void draw (cairo_t *cr, const char *text, int width, int height)
{
    char buf[100];

    cairo_rectangle (cr, BORDER, BORDER, width - 2*BORDER, height - 2*BORDER);
    cairo_set_line_width (cr, 2);
    cairo_stroke (cr);

    cairo_select_font_face (cr, "Sans", CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL);
    cairo_set_font_size (cr, 60);
    cairo_move_to (cr, 200, height/3);
    cairo_show_text (cr, text);

    sprintf (buf, "Width: %d points      Height: %d points", width, height);
    cairo_set_font_size (cr, 18);
    cairo_move_to (cr, 120, height*2/3);
    cairo_show_text (cr, buf);

    sprintf (buf, "This is a test! = D", width, height);
    cairo_set_font_size (cr, 18);
    cairo_move_to (cr, 150, height*5/6);
    cairo_show_text (cr, buf);
}


int setup_socket()
{
    int sockfd, portno, n;

    struct sockaddr_in serv_addr;
    struct hostent *server;
    portno = 9100;
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0)
        error("ERROR opening socket");
    server = gethostbyname("myprinter");

    if (server == NULL) {
        fprintf(stderr,"ERROR, no such host\n");
        exit(0);
    }

    bzero((char *) &serv_addr, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    bcopy((char *)server->h_addr,
         (char *)&serv_addr.sin_addr.s_addr,
         server->h_length);
    serv_addr.sin_port = htons(portno);
    if (connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr)) < 0 )
        error("ERROR connecting");
    return sockfd;
}

static cairo_status_t cairowrite(void *fh, unsigned char const *data, unsigned int length)
{
    if (write(*(int*)fh,data,length) < 0)
         error("ERROR writing to socket");
    return CAIRO_STATUS_SUCCESS;
}

int main(int argc, char *argv[])
{
    int fd = setup_socket();

    cairo_surface_t *surface;
    cairo_t *cr;
    cairo_matrix_t matrix;

    surface = cairo_ps_surface_create_for_stream((cairo_write_func_t)cairowrite, &fd, PAGE_WIDTH, PAGE_HEIGHT);
    cr = cairo_create (surface);

    /* Print portrait page */
    cairo_ps_surface_dsc_begin_page_setup (surface);
    cairo_ps_surface_dsc_comment (surface, "%%PageOrientation: Portrait");
    draw (cr, "Portrait", PAGE_WIDTH, PAGE_HEIGHT);
    cairo_surface_show_page (surface);

    cairo_destroy (cr);
    cairo_surface_finish (surface);
    cairo_surface_destroy (surface);

    close(fd);

    return 0;
}