Add option to forcefully overwrite packages in pack command

Signed-off-by: David Oberhollenzer <goliath@infraroot.at>

include/pkgwriter.h

@@ -1,12 +1,14 @@
 #ifndef PKGWRITER_H
 #define PKGWRITER_H
 
+#include <stdbool.h>
+
 #include "pkgformat.h"
 #include "compressor.h"
 
 typedef struct pkg_writer_t pkg_writer_t;
 
-pkg_writer_t *pkg_writer_open(const char *path);
+pkg_writer_t *pkg_writer_open(const char *path, bool force);
 
 void pkg_writer_close(pkg_writer_t *writer);
 

main/cmd/pack/pack.c

@@ -4,12 +4,14 @@ static const struct option long_opts[] = {
 	{ "description", required_argument, NULL, 'd' },
 	{ "file-list", required_argument, NULL, 'l' },
 	{ "repo-dir", required_argument, NULL, 'r' },
+	{ "force", no_argument, NULL, 'f' },
 	{ NULL, 0, NULL, 0 },
 };
 
-static const char *short_opts = "l:r:d:";
+static const char *short_opts = "l:r:d:f";
 
-static pkg_writer_t *open_writer(pkg_desc_t *desc, const char *repodir)
+static pkg_writer_t *open_writer(pkg_desc_t *desc, const char *repodir,
+				 bool force)
 {
 	char *path;
 
@@ -19,13 +21,14 @@ static pkg_writer_t *open_writer(pkg_desc_t *desc, const char *repodir)
 	path = alloca(strlen(repodir) + strlen(desc->name) + 16);
 	sprintf(path, "%s/%s.pkg", repodir, desc->name);
 
-	return pkg_writer_open(path);
+	return pkg_writer_open(path, force);
 }
 
 static int cmd_pack(int argc, char **argv)
 {
 	const char *filelist = NULL, *repodir = NULL, *descfile = NULL;
 	image_entry_t *list = NULL;
+	bool force = false;
 	pkg_writer_t *wr;
 	pkg_desc_t desc;
 	int i;
@@ -45,6 +48,9 @@ static int cmd_pack(int argc, char **argv)
 		case 'r':
 			repodir = optarg;
 			break;
+		case 'f':
+			force = true;
+			break;
 		default:
 			tell_read_help(argv[0]);
 			return EXIT_FAILURE;
@@ -72,7 +78,7 @@ static int cmd_pack(int argc, char **argv)
 	if (filelist != NULL && filelist_read(filelist, &list))
 		goto fail_desc;
 
-	wr = open_writer(&desc, repodir);
+	wr = open_writer(&desc, repodir, force);
 	if (wr == NULL)
 		goto fail_fp;
 
@@ -113,6 +119,8 @@ static command_t pack = {
 "  --description, -d <path> Specify a file containing a description of the\n"
 "                           package, including information such as package\n"
 "                           dependencies, the actual package name, etc.\n"
+"  --force, -f              If a package with the same name already exists,\n"
+"                           overwrite it.\n"
 "\n",
 	.run_cmd = cmd_pack,
 };

main/pkgwriter.c

@@ -78,10 +78,11 @@ static int flush_to_file(pkg_writer_t *wr)
 	return 0;
 }
 
-pkg_writer_t *pkg_writer_open(const char *path)
+pkg_writer_t *pkg_writer_open(const char *path, bool force)
 {
 	pkg_writer_t *wr = calloc(1, sizeof(*wr));
 	compressor_t *cmp;
+	int flags;
 
 	cmp = compressor_by_id(PKG_COMPRESSION_NONE);
 	if (cmp == NULL) {
@@ -101,7 +102,15 @@ pkg_writer_t *pkg_writer_open(const char *path)
 		goto fail;
 	}
 
-	wr->fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0644);
+	flags = O_WRONLY | O_CREAT;
+
+	if (force) {
+		flags |= O_TRUNC;
+	} else {
+		flags |= O_EXCL;
+	}
+
+	wr->fd = open(path, flags, 0644);
 	if (wr->fd == -1) {
 		perror(path);
 		goto fail_stream;