[Qemu-devel] [PATCH] configure: remove bashism (since 2010)

[Qemu-devel] [PATCH] configure: remove bashism (since 2010)

[marcandre.lureau]

From: Marc-André Lureau <marcandre.lureau@redhat.com>

"type" is not POSIX shell, but a bashism. (found thanks to shellcheck)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 configure | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configure b/configure
index ba57b3f..90eff82 100755
--- a/configure
+++ b/configure
@@ -158,7 +158,7 @@ symlink() {
 # check whether a command is available to this shell (may be either an
 # executable or a builtin)
 has() {
-    type "$1" >/dev/null 2>&1
+    which "$1" >/dev/null 2>&1
 }
 
 # search for an executable in PATH
-- 
2.5.0

Re: [Qemu-devel] [PATCH] configure: remove bashism (since 2010)

[Marc-André Lureau]

Hi

On Thu, Dec 10, 2015 at 1:53 AM,  <marcandre.lureau@redhat.com> wrote:
> From: Marc-André Lureau <marcandre.lureau@redhat.com>
>
> "type" is not POSIX shell, but a bashism. (found thanks to shellcheck)
>

A subsidiary question is whether qemu really care about using POSIX
shell, or we can just depend on bashism. That would help with
simplifying some Makefile lines too.

> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>  configure | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/configure b/configure
> index ba57b3f..90eff82 100755
> --- a/configure
> +++ b/configure
> @@ -158,7 +158,7 @@ symlink() {
>  # check whether a command is available to this shell (may be either an
>  # executable or a builtin)
>  has() {
> -    type "$1" >/dev/null 2>&1
> +    which "$1" >/dev/null 2>&1
>  }
>
>  # search for an executable in PATH
> --
> 2.5.0
>
>



-- 
Marc-André Lureau

Re: [Qemu-devel] [PATCH] configure: remove bashism (since 2010)

[Eric Blake]

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On 12/09/2015 05:53 PM, marcandre.lureau@redhat.com wrote:
> From: Marc-André Lureau <marcandre.lureau@redhat.com>
> 
> "type" is not POSIX shell, but a bashism. (found thanks to shellcheck)

NACK.  'type' is POSIX, and shellcheck is buggy.

http://pubs.opengroup.org/onlinepubs/9699919799/utilities/type.html

> 
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>  configure | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/configure b/configure
> index ba57b3f..90eff82 100755
> --- a/configure
> +++ b/configure
> @@ -158,7 +158,7 @@ symlink() {
>  # check whether a command is available to this shell (may be either an
>  # executable or a builtin)
>  has() {
> -    type "$1" >/dev/null 2>&1
> +    which "$1" >/dev/null 2>&1

Conversely, 'which' is _not_ POSIX, and therefore less portable than 'type'.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH] configure: remove bashism (since 2010)

[Eric Blake]

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On 12/09/2015 05:57 PM, Marc-André Lureau wrote:
> Hi
> 
> On Thu, Dec 10, 2015 at 1:53 AM,  <marcandre.lureau@redhat.com> wrote:
>> From: Marc-André Lureau <marcandre.lureau@redhat.com>
>>
>> "type" is not POSIX shell, but a bashism. (found thanks to shellcheck)
>>
> 
> A subsidiary question is whether qemu really care about using POSIX
> shell, or we can just depend on bashism. That would help with
> simplifying some Makefile lines too.

Debian uses dash, not bash, as /bin/sh.  As both 'configure' and
'Makefile' depend on '/bin/sh', then yes, we care about POSIX compliance.

Only in scripts that explicitly require /bin/bash, such as much of the
scripts under tests/, can we get away with bashisms.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH] configure: remove bashism (since 2010)

[Marc-André Lureau]

Hi

On Thu, Dec 10, 2015 at 3:51 AM, Eric Blake <eblake@redhat.com> wrote:
> On 12/09/2015 05:53 PM, marcandre.lureau@redhat.com wrote:
>> From: Marc-André Lureau <marcandre.lureau@redhat.com>
>>
>> "type" is not POSIX shell, but a bashism. (found thanks to shellcheck)
>
> NACK.  'type' is POSIX, and shellcheck is buggy.
>
> http://pubs.opengroup.org/onlinepubs/9699919799/utilities/type.html

So is checkbashisms then. I am just spreading that wrong idea then :)

>
>>
>> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
>> ---
>>  configure | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/configure b/configure
>> index ba57b3f..90eff82 100755
>> --- a/configure
>> +++ b/configure
>> @@ -158,7 +158,7 @@ symlink() {
>>  # check whether a command is available to this shell (may be either an
>>  # executable or a builtin)
>>  has() {
>> -    type "$1" >/dev/null 2>&1
>> +    which "$1" >/dev/null 2>&1
>
> Conversely, 'which' is _not_ POSIX, and therefore less portable than 'type'.
>
> --
> Eric Blake   eblake redhat com    +1-919-301-3266
> Libvirt virtualization library http://libvirt.org
>



-- 
Marc-André Lureau