bootstrap-initrd

commit: 19d388c6f1b435706d8e86ca02264dd37aba5035
parent 90ca0f51551b0ecf43cd963b07acb9575aeb0baa
Author: Haelwenn (lanodan) Monnier <contact@hacktivis.me>
Date:   Tue, 30 Apr 2024 10:53:33 +0200

cp-stub.c: Even with only one source, destination can be a dir

Diffstat:
M
cp-stub.c
58
++++++++++++++++++++++++++++++++++++++--------------------

1 file changed, 38 insertions(+), 20 deletions(-)
diff --git a/cp-stub.c b/cp-stub.c
@@ -16,27 +16,56 @@
 #include <unistd.h> // getopt, copy_file_range
 
 static int
-do_copy(char *src, char *dest)
+do_copy(char *src, char *dest, bool is_dir)
 {
 	assert(errno == 0);
 	int src_fd = open(src, O_RDONLY);
 	if(src_fd < 0)
 	{
-		fprintf(stderr, "cp: Failed opening file '%s' for reading: %s\n", src, strerror(errno));
+		fprintf(stderr, "cp: Failed opening source '%s' for reading: %s\n", src, strerror(errno));
 		return -1;
 	}
 
 	struct stat src_stat;
 	if(fstat(src_fd, &src_stat) < 0)
 	{
-		fprintf(stderr, "cp: Failed getting status for target '%s': %s\n", dest, strerror(errno));
+		fprintf(stderr, "cp: Failed getting status for source '%s': %s\n", dest, strerror(errno));
 		return -1;
 	}
 
-	int dest_fd = open(dest, O_CREAT | O_WRONLY | O_TRUNC, src_stat.st_mode & 0777);
+	if(!is_dir)
+	{
+		struct stat dest_stat;
+		if(stat(dest, &dest_stat) < 0)
+		{
+			fprintf(stderr, "cp: Failed getting status for target '%s': %s\n", dest, strerror(errno));
+			return -1;
+		}
+		if(S_ISDIR(dest_stat.st_mode)) is_dir = true;
+	}
+
+	char *dest_path = dest;
+
+	if(is_dir)
+	{
+		char target[PATH_MAX] = "";
+
+		char *src_sep      = strrchr(src, '/');
+		char *src_basename = src_sep != NULL ? src_sep + 1 : src;
+
+		if(snprintf(target, PATH_MAX, "%s/%s", dest, src_basename) < 0)
+		{
+			fprintf(stderr, "cp: Failed joining destination '%s' and target '%s'\n", dest, src);
+			return 1;
+		}
+
+		dest_path = target;
+	}
+
+	int dest_fd = open(dest_path, O_CREAT | O_WRONLY | O_TRUNC, src_stat.st_mode & 0777);
 	if(dest_fd < 0)
 	{
-		fprintf(stderr, "cp: Failed create-opening file '%s' for writing: %s\n", dest, strerror(errno));
+		fprintf(stderr, "cp: Failed create-opening destination '%s' for writing: %s\n", dest_path, strerror(errno));
 		return -1;
 	}
 
@@ -50,7 +79,7 @@ do_copy(char *src, char *dest)
 			fprintf(stderr,
 			        "cp: Error: Failed copying data from '%s' to '%s': %s\n",
 			        src,
-			        dest,
+			        dest_path,
 			        strerror(errno));
 			return -1;
 		}
@@ -102,27 +131,16 @@ main(int argc, char *argv[])
 
 	if(argc == 2)
 	{
-		if(do_copy(argv[0], argv[1]) < 0) return 1;
+		if(do_copy(argv[0], argv[1], false) < 0) return 1;
 	}
 	else
 	{
-		char *dest            = argv[argc - 1];
-		char target[PATH_MAX] = "";
+		char *dest = argv[argc - 1];
 
 		for(int i = 0; i < argc - 1; i++)
 		{
 			char *src = argv[i];
-
-			char *src_sep      = strrchr(src, '/');
-			char *src_basename = src_sep != NULL ? src_sep + 1 : src;
-
-			if(snprintf(target, PATH_MAX, "%s/%s", dest, src_basename) < 0)
-			{
-				fprintf(stderr, "cp: Failed joining destination '%s' and target '%s'\n", dest, src);
-				return 1;
-			}
-
-			if(do_copy(src, target) < 0) return 1;
+			if(do_copy(src, dest, true) < 0) return 1;
 		}
 	}