[Libguestfs] [PATCH 1/5] mllib: Enhance and rename 'detect_compression' function so it can detect a few more file types.
---
builder/builder.ml | 6 +++++-
mllib/common_utils.ml | 29 ++++++++++++++++++++---------
mllib/common_utils.mli | 6 ++----
3 files changed, 27 insertions(+), 14 deletions(-)
diff --git a/builder/builder.ml b/builder/builder.ml
index 5195cfd..121c5fb 100644
--- a/builder/builder.ml
+++ b/builder/builder.ml
@@ -315,8 +315,12 @@ let main () =
| None -> []
| Some format -> [`Format, format] in
let compression_tag =
- match detect_compression template with
+ match detect_file_type template with
| `XZ -> [ `XZ, "" ]
+ | `GZip | `Tar | `Zip ->
+ eprintf (f_"%s: input file (%s) has an unsupported type\n")
+ prog template;
+ exit 1
| `Unknown -> [] in
[ `Template, ""; `Filename, template; `Size, Int64.to_string size ] @
format_tag @ compression_tag in
diff --git a/mllib/common_utils.ml b/mllib/common_utils.ml
index adfad3f..295981c 100644
--- a/mllib/common_utils.ml
+++ b/mllib/common_utils.ml
@@ -547,17 +547,28 @@ let rm_rf_only_files (g : Guestfs.guestfs) dir =
List.iter g#rm files
)
-(* Detect compression of a file.
- *
- * Only detects the formats we need in virt-builder so far.
- *)
-let detect_compression filename =
+(* Detect type of a file. *)
+let detect_file_type filename =
let chan = open_in filename in
- let buf = String.create 6 in
- really_input chan buf 0 6;
+ let get start size =
+ try
+ seek_in chan start;
+ let buf = String.create size in
+ really_input chan buf 0 size;
+ Some buf
+ with End_of_file | Invalid_argument _ -> None
+ in
+ let ret =
+ if get 0 6 = Some "\2537zXZ\000" then `XZ
+ else if get 0 4 = Some "PK\003\004" then `Zip
+ else if get 0 4 = Some "PK\005\006" then `Zip
+ else if get 0 4 = Some "PK\007\008" then `Zip
+ else if get 257 6 = Some "ustar\000" then `Tar
+ else if get 257 8 = Some "ustar\x20\x20\000" then `Tar
+ else if get 0 2 = Some "\x1f\x8b" then `GZip
+ else `Unknown in
close_in chan;
- if buf = "\2537zXZ\000" then `XZ
- else `Unknown
+ ret
let is_block_device file =
try (Unix.stat file).Unix.st_kind = Unix.S_BLK
diff --git a/mllib/common_utils.mli b/mllib/common_utils.mli
index d78fd70..112648a 100644
--- a/mllib/common_utils.mli
+++ b/mllib/common_utils.mli
@@ -118,10 +118,8 @@ val rm_rf_only_files : Guestfs.guestfs -> string -> unit
XXX Could be faster with a specific API for doing this. *)
-val detect_compression : string -> [`Unknown | `XZ]
-(** Detect compression of a file.
-
- XXX Only detects the formats we need in virt-builder so far. *)
+val detect_file_type : string -> [`GZip | `Tar | `XZ | `Zip | `Unknown]
+(** Detect type of a file. *)
val is_block_device : string -> bool
val is_char_device : string -> bool
--
2.0.4