* [PATCH] scripts/config: use sed's POSIX interface
@ 2013-07-10 19:58 Clement Chauplannaz
2013-07-10 20:38 ` Yann E. MORIN
0 siblings, 1 reply; 3+ messages in thread
From: Clement Chauplannaz @ 2013-07-10 19:58 UTC (permalink / raw)
To: linux-kbuild; +Cc: mmarek, ak, yann.morin.1998
Script `config' relies on extensions of `GNU sed', and is thus not
working on all Unixes:
- in-place edition of files (-i), which can be replaced with
a temporary file;
- extended-regexps (-r), which can be split into basic regexps;
- single-line calls to `a' command, while some implementations
require a leading newline before the parameter.
Rewrite calls to `sed' program to comply with POSIX interface.
Signed-off-by: Clement Chauplannaz <chauplac@gmail.com>
---
scripts/config | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/scripts/config b/scripts/config
index a65ecbb..3fd95eb 100755
--- a/scripts/config
+++ b/scripts/config
@@ -66,9 +66,14 @@ set_var() {
name_re="^($name=|# $name is not set)"
before_re="^($before=|# $before is not set)"
if test -n "$before" && grep -Eq "$before_re" "$FN"; then
- sed -ri "/$before_re/a $new" "$FN"
+ lf=$'\n'
+ sed -e "/^$before=/a\\$lf$new$lf" \
+ -e "/^# $before is not set/a\\$lf$new$lf" "$FN" >"$FN.swp"
+ mv "$FN.swp" "$FN"
elif grep -Eq "$name_re" "$FN"; then
- sed -ri "s:$name_re.*:$new:" "$FN"
+ sed -e "s:^$name=.*:$new:" \
+ -e "s:^# $name is not set:$new:" "$FN" >"$FN.swp"
+ mv "$FN.swp" "$FN"
else
echo "$new" >>"$FN"
fi
@@ -77,7 +82,8 @@ set_var() {
undef_var() {
local name=$1
- sed -ri "/^($name=|# $name is not set)/d" "$FN"
+ sed -e "/^$name=/d" -e "/^# $name is not set/d" "$FN" >"$FN.swp"
+ mv "$FN.swp" "$FN"
}
if [ "$1" = "--file" ]; then
--
1.8.3.rc1.44.gb387c77.dirty
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] scripts/config: use sed's POSIX interface
2013-07-10 19:58 [PATCH] scripts/config: use sed's POSIX interface Clement Chauplannaz
@ 2013-07-10 20:38 ` Yann E. MORIN
2013-07-10 22:20 ` Clément Chauplannaz
0 siblings, 1 reply; 3+ messages in thread
From: Yann E. MORIN @ 2013-07-10 20:38 UTC (permalink / raw)
To: Clement Chauplannaz; +Cc: linux-kbuild, mmarek, ak
Clément, All,
On 2013-07-10 21:58 +0200, Clement Chauplannaz spake thusly:
> Script `config' relies on extensions of `GNU sed', and is thus not
> working on all Unixes:
> - in-place edition of files (-i), which can be replaced with
> a temporary file;
> - extended-regexps (-r), which can be split into basic regexps;
> - single-line calls to `a' command, while some implementations
> require a leading newline before the parameter.
>
> Rewrite calls to `sed' program to comply with POSIX interface.
Clément, sorry I did not come back to you earlier after your second PM.
Here is further review:
> Signed-off-by: Clement Chauplannaz <chauplac@gmail.com>
> ---
> scripts/config | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/scripts/config b/scripts/config
> index a65ecbb..3fd95eb 100755
> --- a/scripts/config
> +++ b/scripts/config
> @@ -66,9 +66,14 @@ set_var() {
> name_re="^($name=|# $name is not set)"
> before_re="^($before=|# $before is not set)"
> if test -n "$before" && grep -Eq "$before_re" "$FN"; then
> - sed -ri "/$before_re/a $new" "$FN"
> + lf=$'\n'
As you explained me earlier, you expect this to actually set the '\n'
symbol (0x0a) as first char of variable 'lf'. This is a bashism, and is
not POSIX. Here is a test script:
#!/bin/dash
lf=$'\n'
printf "lf='%s'\n" "${lf}"
printf "lf='${lf}'\n"
And the output:
lf='$\n'
lf='$
'
Now, if you use #!/bin/bash, it works as you expect, but not with a
POSIX-only script like dash.
A reliable way to get a single '\n' would be:
lf="$( printf '\n' )"
Yes, config is already a bash script, but no need to add bashisms when
they can be avoided. And since this patch is about POSIX compliance in
the first place... ;-)
Otherwise, LGTM.
Regards,
Yann E. MORIN.
--
.-----------------.--------------------.------------------.--------------------.
| Yann E. MORIN | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software Designer | \ / CAMPAIGN | ___ |
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] scripts/config: use sed's POSIX interface
2013-07-10 20:38 ` Yann E. MORIN
@ 2013-07-10 22:20 ` Clément Chauplannaz
0 siblings, 0 replies; 3+ messages in thread
From: Clément Chauplannaz @ 2013-07-10 22:20 UTC (permalink / raw)
To: Yann E. MORIN; +Cc: linux-kbuild, mmarek, ak
Yann
2013/7/10 Yann E. MORIN <yann.morin.1998@free.fr>:
> Clément, All,
>
> On 2013-07-10 21:58 +0200, Clement Chauplannaz spake thusly:
>> Script `config' relies on extensions of `GNU sed', and is thus not
>> working on all Unixes:
>> - in-place edition of files (-i), which can be replaced with
>> a temporary file;
>> - extended-regexps (-r), which can be split into basic regexps;
>> - single-line calls to `a' command, while some implementations
>> require a leading newline before the parameter.
>>
>> Rewrite calls to `sed' program to comply with POSIX interface.
>
> Clément, sorry I did not come back to you earlier after your second PM.
> Here is further review:
>
>> Signed-off-by: Clement Chauplannaz <chauplac@gmail.com>
>> ---
>> scripts/config | 12 +++++++++---
>> 1 file changed, 9 insertions(+), 3 deletions(-)
>>
>> diff --git a/scripts/config b/scripts/config
>> index a65ecbb..3fd95eb 100755
>> --- a/scripts/config
>> +++ b/scripts/config
>> @@ -66,9 +66,14 @@ set_var() {
>> name_re="^($name=|# $name is not set)"
>> before_re="^($before=|# $before is not set)"
>> if test -n "$before" && grep -Eq "$before_re" "$FN"; then
>> - sed -ri "/$before_re/a $new" "$FN"
>> + lf=$'\n'
>
> As you explained me earlier, you expect this to actually set the '\n'
> symbol (0x0a) as first char of variable 'lf'. This is a bashism, and is
> not POSIX. Here is a test script:
>
> #!/bin/dash
> lf=$'\n'
> printf "lf='%s'\n" "${lf}"
> printf "lf='${lf}'\n"
>
> And the output:
> lf='$\n'
> lf='$
> '
>
> Now, if you use #!/bin/bash, it works as you expect, but not with a
> POSIX-only script like dash.
>
> A reliable way to get a single '\n' would be:
>
> lf="$( printf '\n' )"
This looks like a good idea. I need to work it more in depth though,
as the "single-newline" printf seems to get caught by bash as an IFS -
in other words, it produces an empty var. I'll come back to you with
my findings.
>
> Yes, config is already a bash script, but no need to add bashisms when
> they can be avoided. And since this patch is about POSIX compliance in
> the first place... ;-)
Well, it's more about POSIX compliance for utilities (grep, sed, find,
etc.) which share the same name, a somewhat loose common interface,
but a different implementation between GNU & *BSD. I'm assuming bash
under Linux and *BSD comes from the same source :-).
Besides, I can't say to what extent `config' script complies with
POSIX shell interface and how it would run under other shells...
>
> Otherwise, LGTM.
>
Best regards,
Clement
> Regards,
> Yann E. MORIN.
>
> --
> .-----------------.--------------------.------------------.--------------------.
> | Yann E. MORIN | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
> | +33 662 376 056 | Software Designer | \ / CAMPAIGN | ___ |
> | +33 223 225 172 `------------.-------: X AGAINST | \e/ There is no |
> | http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL | v conspiracy. |
> '------------------------------^-------^------------------^--------------------'
^ permalink raw reply [flat|nested] 3+ messages in thread
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2013-07-10 19:58 [PATCH] scripts/config: use sed's POSIX interface Clement Chauplannaz
2013-07-10 20:38 ` Yann E. MORIN
2013-07-10 22:20 ` Clément Chauplannaz
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