3 files changed, 57 insertions, 9 deletions

diff --git a/snag/src/download_db.c b/snag/src/download_db.c
index 3f51347..819474e 100644
--- a/snag/src/download_db.c
+++ b/snag/src/download_db.c
@@ -8,13 +8,16 @@
 #include <string.h>
 #include <errno.h>
 
-// curl context
-CURL *curl = NULL;
+// note: fixed location of download database for now
+const char download_db_path[] = "../downloads";
 
 // libcrpyto context
 EVP_MD_CTX *mdctx = NULL;
 const EVP_MD *md = NULL;
 
+// curl context
+CURL *curl = NULL;
+
 static size_t curl_write_cb(char* ptr, size_t size, size_t nmemb, void* usrdata)
 {
 	// write the curl data to the file in usr data
@@ -52,18 +55,17 @@ bool download_package(package_info_t* pkg) {
 	// initialize up sha256 hash
     EVP_DigestInit_ex(mdctx, md, NULL);
 
-	// open file for writing and give it to the curl callback
-	// todo(jqj): get actual path with name
-	char* download_path = "download.tar.gz";
+	// open file for writing
+	char* download_path = vastrcat(download_db_path, "/", pkg->attrs.id, "-", pkg->attrs.version, ".tar.gz");
 	FILE* download_file = fopen(download_path, "wb");
 	if (download_file == NULL) die("failed open download file for writing (%s): %s", download_path, strerror(errno));
-	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, curl_write_cb);
-	curl_easy_setopt(curl, CURLOPT_WRITEDATA, download_file);
 
-	// make curl request
+	// make curl request with url and output file
 	// callback writes to the file and feeds the hash
 	curl_easy_setopt(curl, CURLOPT_URL, pkg->attrs.source_url);
 	curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
+	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, curl_write_cb);
+	curl_easy_setopt(curl, CURLOPT_WRITEDATA, download_file);
 	CURLcode result = curl_easy_perform(curl);
     if(result != CURLE_OK) {
 		log("failed to download package with curl: %s", curl_easy_strerror(result));
@@ -75,7 +77,7 @@ bool download_package(package_info_t* pkg) {
 	unsigned int hash_len;
     EVP_DigestFinal_ex(mdctx, hash, &hash_len);
 
-	// get hexadecimal string of sha256 hash
+	// make hexadecimal string of sha256 hash
 	char hash_hex[SHA256_DIGEST_LENGTH * 2 + 1];
 	for(int i = 0; i < SHA256_DIGEST_LENGTH; i++) {
         sprintf(hash_hex + i*2,"%02x", hash[i]);
diff --git a/snag/src/util.c b/snag/src/util.c
index e79fd34..79c4b17 100644
--- a/snag/src/util.c
+++ b/snag/src/util.c
@@ -78,7 +78,49 @@ char* vastrcat_(int dummy, ...) {
 	char* output = malloc(len + 1);
     if (!output) return NULL;
 	char* p = output;
+    while ((arg = va_arg(args2, char*))) {
+		size_t alen = strlen(arg);
+		memcpy(p, arg, alen);
+		p += alen;
+    }
+	output[len] = '\0';
+    va_end(args2);
+
+	return output;
+}
+
+char* join_path_(int dummy, ...) {
+
+    va_list args;
+    va_list args2;
+    va_start(args, dummy);
+	va_copy(args2, args);
+
+	// note(jqj): some path joining libraries reset if they encounter an
+	//            absolute path, we could implement that easily, but I'm not
+	//            sure about it
+
+	// get len of output path
+	size_t len = 0;
+    char* arg = NULL;
+	int i = 0;
     while ((arg = va_arg(args, char*))) {
+		if (i > 0) len += 1;
+		len += strlen(arg) + 1;
+		++i;
+    }
+    va_end(args);
+
+	// allocate and build output
+	char* output = malloc(len + 1);
+    if (!output) return NULL;
+	char* p = output;
+    while ((arg = va_arg(args2, char*))) {
+		if (p != output) {
+			// add slash before every part except the first
+			*p = '/';
+			++p;
+		}
 		size_t alen = strlen(arg);
 		memcpy(p, arg, alen);
 		p += alen;
diff --git a/snag/src/util.h b/snag/src/util.h
index 1a05ab0..081b570 100644
--- a/snag/src/util.h
+++ b/snag/src/util.h
@@ -28,4 +28,8 @@ void print(const char* format, ...) __attribute__((format(printf, 1, 2)));
 #define vastrcat(...) vastrcat_(0, __VA_ARGS__, NULL)
 char* vastrcat_(int dummy, ...);
 
+// posix path functions
+#define join_path(...) join_path_(0, __VA_ARGS__, NULL)
+char* join_path_(int dummy, ...);
+
 #endif