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/* See COPYING file for copyright, license and warranty details. */
/* NOTE: there's now a new api that returns json.
* it requires https, which we don't yet support.
* https://www.googleapis.com/books/v1/volumes?q=isbn:1589235126
* https://www.googleapis.com/books/v1/volumes/jglfL_eVG4cC */
#define VERSION "prealpha"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "util.c"
#define usage "getgbook " VERSION " - a google books downloader\n" \
"usage: getgbook [-p|-a] isbn\n" \
" -p print all available pages\n" \
" -a download all available pages\n" \
" otherwise, all pages in stdin will be downloaded\n"
#define URLMAX 1024
#define BOOKID_LEN 12
typedef struct {
int num;
char url[URLMAX];
char name[80];
} Page;
char *getbookid(char *isbn)
{
char url[URLMAX];
char *buf, *bookid, *c;
snprintf(url, URLMAX, "/books/feeds/volumes?q=isbn:%s", isbn);
if(!get("books.google.com", url, &buf))
return NULL;
if((c = strstr(buf,"<dc:identifier>")) == NULL)
return NULL;
bookid = malloc(sizeof(char *) * BOOKID_LEN);
strncpy(bookid, c+15, BOOKID_LEN);
bookid[BOOKID_LEN] = '\0';
free(buf);
return bookid;
}
int gettotalpages(char *bookid)
{
char url[URLMAX];
char *buf, *c;
int total;
snprintf(url, URLMAX, "/books/feeds/volumes/%s", bookid);
bookid = malloc(sizeof(char *) * BOOKID_LEN);
if(!get("books.google.com", url, &buf))
return 0;
if((c = strstr(buf," pages</dc:format>")) == NULL)
return 0;
while(*c && *c != '>') c--;
sscanf(c+1, "%d ", &total);
return total;
}
Page *getpagedetail(char *bookid, char *pg)
{
char url[URLMAX];
char *buf, *c, *d, m[80], *p;
Page *page;
snprintf(url, URLMAX, "/books?id=%s&pg=%s&jscmd=click3", bookid, pg);
if(!get("books.google.com", url, &buf))
return NULL;
snprintf(m, 80, "\"pid\":\"%s\"", pg);
if((c = strstr(buf,m)) == NULL) {
free(buf); return NULL;
}
page = malloc(sizeof(Page));
strncpy(page->name, pg, 80);
page->url[0] = '\0';
page->num = 0;
if(strncmp(c+strlen(m)+1, "\"src\"", 5) != 0) {
free(buf); return page;
}
for(p=page->url, d=c+strlen(m)+8; *d && *d != '"'; d++, p++) {
if(!strncmp(d, "\\u0026", 6)) {
*p = '&';
d+=5;
} else
*p = *d;
}
*p = '\0';
for(; *d; d++) {
if(*d == '}') {
break;
}
if(!strncmp(d, "\"order\"", 7)) {
sscanf(d+8, "%d,", &(page->num));
break;
}
}
free(buf);
return page;
}
int main(int argc, char *argv[])
{
char *bookid, pg[16], buf[1024], n[80];
int totalpages, i;
Page *page;
if(argc < 2 || argc > 3 ||
(argv[1][0]=='-' && ((argv[1][1]!='p' && argv[1][1]!='a') || argc < 3)))
die(usage);
if((bookid = getbookid(argv[argc-1])) == NULL)
die("Could not find book\n");
if(argv[1][0] == '-') {
/* note this isn't the best way, not least because it misses the
* non PA pages. best is to crawl around the json grabbing everything
* available, by starting on PP1, and filling in by going through
* all pages in totalpages. */
if(!(totalpages = gettotalpages(bookid)))
die("Book has no pages\n");
for(i=1; i<totalpages; i++) {
snprintf(pg, 16, "%s%d", "PA", i);
if((page = getpagedetail(bookid, pg)) == NULL || page->url[0] == '\0') {
fprintf(stderr, "%s failed\n", pg);
free(page);
continue;
}
if(argv[1][1] == 'a') {
snprintf(n, 80, "%05d.png", page->num);
gettofile(page->url, n);
printf("Downloaded page %d\n", page->num);
} else
printf("%d\n", page->num);
free(page);
}
} else {
/* todo: find the page based on its order number, rather than using PA%d */
while(fgets(buf, 1024, stdin)) {
sscanf(buf, "%d", &i);
snprintf(pg, 16, "%s%d", "PA", i);
if((page = getpagedetail(bookid, pg)) == NULL || page->url[0] == '\0') {
fprintf(stderr, "%d failed\n", i);
free(page);
continue;
}
snprintf(n, 80, "%05d.png", page->num);
gettofile(page->url, n);
printf("Downloaded page %d\n", page->num);
free(page);
}
}
free(bookid);
return EXIT_SUCCESS;
}
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