xbps-install(1): added -D, --download-only.

Added `-D, --download-only` flag to allow downloading
packages to the cache without attempting to install them.

Contributed by Toyam Cox via #9

Adapted to master by yours truly.

Close #9

NEWS

@@ -1,6 +1,10 @@
 xbps-0.55 (???):
 
- * xbps-install(1): added `-I --ignore-file-conflicts` to not abort
+ * xbps-install(1): Added `-D, --download-only` flag to allow
+   downloading packages to the cache without attempting to
+   install them. [Toyam Cox]
+
+ * xbps-install(1): added `-I, --ignore-file-conflicts` to not abort
    the transaction even if file conflicts were detected. [xtraeme]
 
  * xbps-install(1): return 0 if package is already installed,

bin/xbps-install/main.c

@@ -47,6 +47,7 @@ usage(bool fail)
 	    " -C --config <dir>          Path to confdir (xbps.d)\n"
 	    " -c --cachedir <dir>        Path to cachedir\n"
 	    " -d --debug                 Debug mode shown to stderr\n"
+	    " -D --download-only         Download packages and check integrity, nothing else.\n"
 	    " -f --force                 Force package re-installation\n"
 	    "                            If specified twice, all files will be\n"
 	    "                            overwritten.\n"
@@ -95,12 +96,13 @@ repo_import_key_cb(struct xbps_repo *repo, void *arg UNUSED, bool *done UNUSED)
 int
 main(int argc, char **argv)
 {
-	const char *shortopts = "AC:c:dfhIiMnR:r:SuUVvy";
+	const char *shortopts = "AC:c:DdfhIiMnR:r:SuUVvy";
 	const struct option longopts[] = {
 		{ "automatic", no_argument, NULL, 'A' },
 		{ "config", required_argument, NULL, 'C' },
 		{ "cachedir", required_argument, NULL, 'c' },
 		{ "debug", no_argument, NULL, 'd' },
+		{ "download-only", no_argument, NULL, 'D' },
 		{ "force", no_argument, NULL, 'f' },
 		{ "help", no_argument, NULL, 'h' },
 		{ "ignore-conf-repos", no_argument, NULL, 'i' },
@@ -144,6 +146,9 @@ main(int argc, char **argv)
 		case 'd':
 			flags |= XBPS_FLAG_DEBUG;
 			break;
+		case 'D':
+			flags |= XBPS_FLAG_DOWNLOAD_ONLY;
+			break;
 		case 'f':
 			fflag++;
 			if (fflag > 1)

bin/xbps-install/xbps-install.1

@@ -72,6 +72,11 @@ If the first character is not '/' then it's a relative path of
 .Ar rootdir .
 .It Fl d, Fl -debug
 Enables extra debugging shown to stderr.
+.It Fl D, Fl -download-only
+Only download packages to the cache, do not do any other installation steps.
+This may be useful for doing system upgrades while offline, or automatically
+downloading updates while leaving you with the option of still manually running
+the update.
 .It Fl f, Fl -force
 Force downgrade installation (if package version in repos is less than installed version),
 or reinstallation (if package version in repos is the same) to the target

include/xbps.h.in

@@ -210,11 +210,18 @@
 #define XBPS_FLAG_UNPACK_ONLY 		0x00001000
 
 /**
+ * @def XBPS_FLAG_DOWNLOAD_ONLY
+ * Only download packages to the cache, do not do any installation steps.
+ * Must be set through the xbps_handle::flags member.
+ */
+#define XBPS_FLAG_DOWNLOAD_ONLY		0x00002000
+
+/*
  * @def XBPS_FLAG_IGNORE_FILE_CONFLICTS
  * Continue with transaction even if there are file conflicts.
  * Must be set through the xbps_handle::flags member.
  */
-#define XBPS_FLAG_IGNORE_FILE_CONFLICTS	0x00002000
+#define XBPS_FLAG_IGNORE_FILE_CONFLICTS	0x00004000
 
 /**
  * @def XBPS_FETCH_CACHECONN
@@ -1282,7 +1289,6 @@ xbps_dictionary_t xbps_archive_fetch_plist(const char *url, const char *p);
 /** @addtogroup repopool */
 /*@{*/
 
-
 /**
  * @struct xbps_repo xbps.h "xbps.h"
  * @brief Repository structure
@@ -1633,7 +1639,6 @@ xbps_array_t xbps_repo_get_pkg_revdeps(struct xbps_repo *repo, const char *pkg);
  */
 int xbps_repo_key_import(struct xbps_repo *repo);
 
-
 /*@}*/
 
 /** @addtogroup archive_util */

lib/transaction_commit.c

@@ -255,6 +255,10 @@ xbps_transaction_commit(struct xbps_handle *xhp)
 		    "%s\n", strerror(rv));
 		goto out;
 	}
+	if (xhp->flags & XBPS_FLAG_DOWNLOAD_ONLY) {
+		goto out;
+	}
+
 	/*
 	 * Collect files in the transaction and find some issues
 	 * like multiple packages installing the same file.
@@ -265,6 +269,7 @@ xbps_transaction_commit(struct xbps_handle *xhp)
 		    "%s\n", strerror(rv));
 		goto out;
 	}
+
 	/*
 	 * Install, update, configure or remove packages as specified
 	 * in the transaction dictionary.