Re: [Qemu-devel] [RFC PATCH v3 03/11] Add a script to extract VSS SDK headers on POSIX system

[Laszlo Ersek]

On 05/21/13 17:33, Tomoki Sekiyama wrote:
> VSS SDK(*) setup.exe is only runnable on Windows. This adds a script
> to extract VSS SDK headers on POSIX-systems using msitools.
> 
>   * http://www.microsoft.com/en-us/download/details.aspx?id=23490
> 
> From: Paolo Bonzini <address@hidden>
> Signed-off-by: Tomoki Sekiyama <address@hidden>
> ---
>  scripts/extract-vsssdk-headers |   25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
>  create mode 100755 scripts/extract-vsssdk-headers
> 
> diff --git a/scripts/extract-vsssdk-headers b/scripts/extract-vsssdk-headers
> new file mode 100755
> index 0000000..5877137
> --- /dev/null
> +++ b/scripts/extract-vsssdk-headers
> @@ -0,0 +1,25 @@
> +#! /bin/bash
> +
> +# extract-vsssdk-headers
> +# Author: Paolo Bonzini <address@hidden>
> +
> +set -e
> +if test $# = 0 || ! test -f "$1"; then
> +  echo 'Usage: extract-vsssdk-headers /path/to/setup.exe'
> +  exit 1
> +fi

Error message to >&2 ?

(Would not be worth a repost but you're already doing one...)

> +
> +# Extract .MSI file in the .exe, looking for the OLE compound
> +# document signature.  Extra data at the end does not matter.
> +export LC_ALL=C
> +MAGIC=$'\xd0\xcf\x11\xe0\xa1\xb1\x1a\xe1'

Can't help mentioning the following portable (alas, octal) equivalent :)

MAGIC=$(printf '%b' '\0320\0317\0021\0340\0241\0261\0032\0341')

<http://pubs.opengroup.org/onlinepubs/9699919799/utilities/printf.html#tag_20_94>

> +offset=`grep -abom1 "$MAGIC" "$1" | sed -n 's/:/\n/; P' `

Of these grep options, none are portable, hence I'm supposing dependency
on GNU grep. In that case, see (*).

> +(dd of=/dev/null skip=$offset bs=1 count=0; cat) < "$1" > vsssdk.msi

In place of dd for seeking + cat, suggest

  tail -c +$((offset+1)) -- "$1"

<http://pubs.opengroup.org/onlinepubs/9699919799/utilities/tail.html>

> +
> +# Now extract the files.
> +tmpdir=tmp$$
> +mkdir $tmpdir
> +msiextract -C $tmpdir vsssdk.msi
> +mv "$tmpdir/Program Files/Microsoft/VSSSDK72/inc" inc
> +rm -rf $tmpdir vsssdk.msi
> +exit 0

(*) Since we rely on GNU utilities anyway, I propose the mktemp utility
("Written by Jim Meyering and Eric Blake", heh) from GNU coreutils:

tmpdir=$(mktemp -d)


Feel free to ignore any of the above, of course :)

Thanks,
Laszlo