unpack source function unpacks tarballs (very hard)

2 files changed, 62 insertions, 0 deletions

diff --git a/snag/scripts/extract_tar_contents.sh b/snag/scripts/extract_tar_contents.sh
new file mode 100755
index 0000000..a50a1a7
--- /dev/null
+++ b/snag/scripts/extract_tar_contents.sh
@@ -0,0 +1,38 @@
+#!/bin/sh
+set -e
+
+# extracts a tarball's contents to the output directory.
+# if the tarball contains just one directory, extract those contents
+#
+# we can rewrite this script in c eventually, if we want
+
+if [ -z "$1" -o -z "$2" ]; then
+    echo "Usage: $0 <tarball> <output_directory>" >&2
+    exit 1
+fi
+
+tarball="$1"
+target="$2"
+
+is_one_directory() {
+	if [ $(echo $1 | wc -l) -ne 1 ]; then
+		return 1
+	fi
+	case "$1" in
+		*/) return 0 ;;
+		*)  return 1 ;;
+	esac
+}
+
+# get top level paths in tarball
+tlps=$(tar -tf "$tarball" | grep -E '^(./)?[^/]+/?$')
+
+if is_one_directory "$tlps"; then
+	# if only one top level directory, extract it and rename it
+	tar xf "$tarball"
+	mv "$tlps" "$target"
+else
+	# if a bunch of files or directories, extract them in a directory
+	mkdir $target
+	tar xf "$tarball" -C "$target"
+fi
diff --git a/snag/src/source_db.c b/snag/src/source_db.c
index ab7ec99..86bab8b 100644
--- a/snag/src/source_db.c
+++ b/snag/src/source_db.c
@@ -9,6 +9,8 @@
 #include <unistd.h>
 #include <errno.h>
 
+#define EXTRACT_TAR_SCRIPT "./scripts/extract_tar_contents.sh"
+
 // libcrpyto context
 EVP_MD_CTX *mdctx = NULL;
 const EVP_MD *md = NULL;
@@ -101,6 +103,28 @@ static size_t download_write_callback(char* ptr, size_t size, size_t nmemb, void
 	return written;
 }
 
+bool unpack_source(source_info_t* source, char* dest_path) {
+
+	char* source_path = get_source_path(source);
+	char* command = vastrcat(EXTRACT_TAR_SCRIPT, " ", source_path, " ", dest_path);
+
+	// just run the unpack script. we can rewrite in c in the future
+	int ret = system(command);
+	if (ret == -1) {
+		die("failed to execute unpack command '%s': %s", command, strerror(errno));
+    } else if (!WIFEXITED(ret)) {
+		die("failed to execute unpack command '%s' (didn't exit)", command);
+	} else if (WEXITSTATUS(ret) != 0) {
+		die("unpack command '%s' failed: exit status %d", command, WEXITSTATUS(ret));
+	}
+
+	free(command);
+	free(source_path);
+
+	return true;
+}
+
+
 void ensure_libcrypto() {
 	if (mdctx == NULL) {
 		mdctx = EVP_MD_CTX_new();