Pretty printing

main.c

@@ -18,6 +18,8 @@
 
 #include <stdio.h>
 #include <string.h>
+#include <getopt.h>
+#include <stdbool.h>
 
 #include "convert.h"
 #include "util.h"
@@ -160,15 +162,29 @@ static void export_book(const char path[], Book* book) {
 }
 
 int main(int argc, char *argv[]) {
-    if (argc != 2) {
-        fprintf(stderr, "usage: %s dictionary_path\n", argv[0]);
-        return 2;
+    bool pretty_print = false;
+
+    char opt;
+    while ((opt = getopt(argc, argv, "p")) != -1) {
+        switch (opt) {
+            case 'p':
+                pretty_print = true;
+                break;
+            default:
+                exit(EXIT_FAILURE);
+                break;
+        }
     }
-    else {
-        Book book = {};
-        export_book(argv[1], &book);
-        dump_book(&book, stdout);
-        free_book(&book);
-        return 1;
+
+    if (optind >= argc) {
+        fprintf(stderr, "Usage: %s [-p] dictionary_path\n", argv[0]);
+        exit(EXIT_FAILURE);
     }
+
+    Book book = {};
+    export_book(argv[optind], &book);
+    dump_book(&book, pretty_print, stdout);
+    free_book(&book);
+
+    return 0;
 }

util.c

@@ -136,11 +136,11 @@ static void encode_book(Book* book, json_t* book_json) {
     json_decref(subbook_json_array);
 }
 
-void dump_book(Book* book, FILE* fp) {
+void dump_book(Book* book, bool pretty_print, FILE* fp) {
     json_t* book_json = json_object();
     encode_book(book, book_json);
 
-    char* output = json_dumps(book_json, JSON_COMPACT);
+    char* output = json_dumps(book_json, pretty_print ? JSON_INDENT(4) : JSON_COMPACT);
     if (output != NULL) {
         fputs(output, fp);
     }

util.h

@@ -20,7 +20,9 @@
 #define UTIL_H
 
 #include <stdlib.h>
+#include <stdbool.h>
 #include <stdio.h>
+
 #include "eb/eb/eb.h"
 
 /*
@@ -72,7 +74,7 @@ typedef enum {
 char* read_book_data(EB_Book* book, const EB_Position* position, ReadMode mode);
 
 void free_book(Book* book);
-void dump_book(Book* book, FILE* fp);
+void dump_book(Book* book, bool pretty_print, FILE* fp);
 
 
 #endif