[PATCH] Remove bashisms from scripts/extract-ikconfig

[PATCH] Remove bashisms from scripts/extract-ikconfig

[Christian Kujau]

Hi,

I noticed that scripts/extract-ikconfig is using /bin/sh in its shebang 
but when /bin/sh is not a symlink to bash, it breaks with:

# scripts/extract-ikconfig /boot/vmlinux
scripts/extract-ikconfig: 11: function: not found
scripts/extract-ikconfig: 12: typeset: not found

The diff below seems to fix this.

Signed-off-by: Christian Kujau <lists@nerdbynature.de>

--- linux-2.6-dev/scripts/extract-ikconfig.orig	2007-06-01 22:53:49.000000000 +0200
+++ linux-2.6-dev/scripts/extract-ikconfig	2007-06-01 23:00:54.000000000 +0200
@@ -8,8 +8,8 @@ test -e $binoffset || cc -o $binoffset .

  IKCFG_ST="0x49 0x4b 0x43 0x46 0x47 0x5f 0x53 0x54"
  IKCFG_ED="0x49 0x4b 0x43 0x46 0x47 0x5f 0x45 0x44"
-function dump_config {
-    typeset file="$1"
+dump_config() {
+    file="$1"

      start=`$binoffset $file $IKCFG_ST 2>/dev/null`
      [ "$?" != "0" ] && start="-1"
@@ -18,8 +18,8 @@ function dump_config {
      fi
      end=`$binoffset $file $IKCFG_ED 2>/dev/null`

-    let start="$start + 8"
-    let size="$end - $start"
+    start="`expr $start + 8`"
+    size="`expr $end - $start`"

      dd if="$file" ibs=1 skip="$start" count="$size" 2>/dev/null | zcat


-- 
make bzImage, not war

Re: [PATCH] Remove bashisms from scripts/extract-ikconfig

[Julio M. Merino Vidal]

On 09/06/2007, at 21:22, Christian Kujau wrote:

> Hi,
>
> I noticed that scripts/extract-ikconfig is using /bin/sh in its  
> shebang but when /bin/sh is not a symlink to bash, it breaks with:
> [...]
> @@ -18,8 +18,8 @@ function dump_config {
>      fi
>      end=`$binoffset $file $IKCFG_ED 2>/dev/null`
>
> -    let start="$start + 8"
> -    let size="$end - $start"
> +    start="`expr $start + 8`"
> +    size="`expr $end - $start`"

Wouldn't this be better expressed as:

     start=$(($start + 8))
     size=$(($end - $start))

to avoid invoking a subshell?

-- 
Julio M. Merino Vidal <jmerino@ac.upc.edu>

Re: [PATCH] Remove bashisms from scripts/extract-ikconfig

[Christian Kujau]

On Sat, 9 Jun 2007, Julio M. Merino Vidal wrote:
> Wouldn't this be better expressed as:
>
>   start=$(($start + 8))
>   size=$(($end - $start))
>
> to avoid invoking a subshell?

This is certainly possible for lots for scripts, but was not the "scope" 
of this patch. ` is not bash-specific and does not break anything.

-- 
make bzImage, not war

Re: [PATCH] Remove bashisms from scripts/extract-ikconfig

[Julio M. Merino Vidal]

On 09/06/2007, at 21:34, Christian Kujau wrote:

> On Sat, 9 Jun 2007, Julio M. Merino Vidal wrote:
>> Wouldn't this be better expressed as:
>>
>>   start=$(($start + 8))
>>   size=$(($end - $start))
>>
>> to avoid invoking a subshell?
>
> This is certainly possible for lots for scripts, but was not the  
> "scope" of this patch. ` is not bash-specific and does not break  
> anything.

$((...)) is not bash-specific either.

-- 
Julio M. Merino Vidal <jmerino@ac.upc.edu>

Re: [PATCH] Remove bashisms from scripts/extract-ikconfig

[Willy Tarreau]

On Sat, Jun 09, 2007 at 09:34:36PM +0200, Christian Kujau wrote:
> On Sat, 9 Jun 2007, Julio M. Merino Vidal wrote:
> >Wouldn't this be better expressed as:
> >
> >  start=$(($start + 8))
> >  size=$(($end - $start))
> >
> >to avoid invoking a subshell?
> 
> This is certainly possible for lots for scripts, but was not the "scope" 
> of this patch. ` is not bash-specific and does not break anything.

That's wrong. It will now require "expr" to be present and working on
the machine, eventhough it's certainly needed for other parts of the
kernel. Also, the remaining function will be considerably slower than
what it initially was. If it's called very frequently, it can be a
problem.

I agree with Julio that if you want to fix the code for its bashism,
you should not change its behaviour and stay as much as possible close
to what it initially did.

Also, beware that the "typeset file=y" did another thing : declare "file"
as local to the function. With your change, any global variable called
"file" will have its content wiped after a call to this function. You
should ensure that it is not used anywhere else, or better, change its
name for something less common than "file".

Regards,
Willy

Re: [PATCH] Remove bashisms from scripts/extract-ikconfig

[Christian Kujau]

On Sat, 9 Jun 2007, Willy Tarreau wrote:
> That's wrong. It will now require "expr" to be present and working on
> the machine, eventhough it's certainly needed for other parts of the

Oh, I was under the strange assumption that "expr" was a shell-builtin. 
Well, it's not so I guess I'll just live with the bashism or try to 
implement your proposals.

Thank you both for your comments,
Christian.
-- 
make bzImage, not war

Re: [PATCH] Remove bashisms from scripts/extract-ikconfig

[Randy Dunlap]

Hi Christian,

Does the patch below satisfy your needs here?

Thanks,
~Randy

---

From: Christian Kujau <lists@nerdbynature.de>

Remove bashisms from scripts/extract-ikconfig (function and
typeset words).

Tested under dash v0.5.4 (latest/current).

Signed-off-by: Christian Kujau <lists@nerdbynature.de>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
---
 scripts/extract-ikconfig |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- linux-2.6.24-rc2-git2.orig/scripts/extract-ikconfig
+++ linux-2.6.24-rc2-git2/scripts/extract-ikconfig
@@ -8,8 +8,9 @@ test -e $binoffset || cc -o $binoffset .
 
 IKCFG_ST="0x49 0x4b 0x43 0x46 0x47 0x5f 0x53 0x54"
 IKCFG_ED="0x49 0x4b 0x43 0x46 0x47 0x5f 0x45 0x44"
-function dump_config {
-    typeset file="$1"
+
+dump_config() {
+    file="$1"
 
     start=`$binoffset $file $IKCFG_ST 2>/dev/null`
     [ "$?" != "0" ] && start="-1"
@@ -27,7 +28,6 @@ function dump_config {
     exit 0
 }
 
-
 usage()
 {
 	echo "  usage: extract-ikconfig [b]zImage_filename"

[PATCH] remove bashisms from scripts/extract-ikconfig

[Werner Almesberger]

unbashify-extract-ikconfig.patch

scripts/extract-ikconfig contains a lot of gratuituous bashisms,
which make it fail if /bin/sh isn't bash. This patch replaces them
with regular Bourne shell constructs.

Signed-off-by: Werner Almesberger <werner@openmoko.org>

---

diff --git a/scripts/extract-ikconfig b/scripts/extract-ikconfig
index 8187e6f..72997c3 100755
--- a/scripts/extract-ikconfig
+++ b/scripts/extract-ikconfig
@@ -8,8 +8,8 @@ test -e $binoffset || cc -o $binoffset ./scripts/binoffset.c || exit 1
 
 IKCFG_ST="0x49 0x4b 0x43 0x46 0x47 0x5f 0x53 0x54"
 IKCFG_ED="0x49 0x4b 0x43 0x46 0x47 0x5f 0x45 0x44"
-function dump_config {
-    typeset file="$1"
+dump_config() {
+    file="$1"
 
     start=`$binoffset $file $IKCFG_ST 2>/dev/null`
     [ "$?" != "0" ] && start="-1"
@@ -18,8 +18,8 @@ function dump_config {
     fi
     end=`$binoffset $file $IKCFG_ED 2>/dev/null`
 
-    let start="$start + 8"
-    let size="$end - $start"
+    start=`expr $start + 8`
+    size=`expr $end - $start`
 
     dd if="$file" ibs=1 skip="$start" count="$size" 2>/dev/null | zcat
 

Re: [PATCH] remove bashisms from scripts/extract-ikconfig

[Randy Dunlap]

Werner Almesberger wrote:
> unbashify-extract-ikconfig.patch
> 
> scripts/extract-ikconfig contains a lot of gratuituous bashisms,
> which make it fail if /bin/sh isn't bash. This patch replaces them
> with regular Bourne shell constructs.
> 
> Signed-off-by: Werner Almesberger <werner@openmoko.org>

Acked-by: Randy Dunlap <randy.dunlap@oracle.com> # as file author


> ---
> 
> diff --git a/scripts/extract-ikconfig b/scripts/extract-ikconfig
> index 8187e6f..72997c3 100755
> --- a/scripts/extract-ikconfig
> +++ b/scripts/extract-ikconfig
> @@ -8,8 +8,8 @@ test -e $binoffset || cc -o $binoffset ./scripts/binoffset.c || exit 1
>  
>  IKCFG_ST="0x49 0x4b 0x43 0x46 0x47 0x5f 0x53 0x54"
>  IKCFG_ED="0x49 0x4b 0x43 0x46 0x47 0x5f 0x45 0x44"
> -function dump_config {
> -    typeset file="$1"
> +dump_config() {
> +    file="$1"
>  
>      start=`$binoffset $file $IKCFG_ST 2>/dev/null`
>      [ "$?" != "0" ] && start="-1"
> @@ -18,8 +18,8 @@ function dump_config {
>      fi
>      end=`$binoffset $file $IKCFG_ED 2>/dev/null`
>  
> -    let start="$start + 8"
> -    let size="$end - $start"
> +    start=`expr $start + 8`
> +    size=`expr $end - $start`
>  
>      dd if="$file" ibs=1 skip="$start" count="$size" 2>/dev/null | zcat
>  
> --


-- 
~Randy

Re: [PATCH] remove bashisms from scripts/extract-ikconfig

[Sam Ravnborg]

On Wed, Nov 12, 2008 at 04:39:35PM -0200, Werner Almesberger wrote:
> unbashify-extract-ikconfig.patch
> 
> scripts/extract-ikconfig contains a lot of gratuituous bashisms,
> which make it fail if /bin/sh isn't bash. This patch replaces them
> with regular Bourne shell constructs.
> 
> Signed-off-by: Werner Almesberger <werner@openmoko.org>

Applied to kbuild-next with Randy's ack.

	Sam