* [PATCH] dtdiff: change to POSIX shell
@ 2018-01-10 5:47 Mike Frysinger
[not found] ` <20180110054756.23464-1-vapier-aBrp7R+bbdUdnm+yROfE0A@public.gmane.org>
0 siblings, 1 reply; 5+ messages in thread
From: Mike Frysinger @ 2018-01-10 5:47 UTC (permalink / raw)
To: devicetree-compiler-u79uwXL29TY76Z2rM5mHXA
From: Mike Frysinger <vapier-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
This changes from the bash-specific process substitution feature to
reading with pipes. It relies on /dev/fd or /proc/self/fd existing.
URL: https://crbug.com/756559
Signed-off-by: Mike Frysinger <vapier-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
---
dtdiff | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/dtdiff b/dtdiff
index 5fa772b0ab62..4d1b71756c2f 100644
--- a/dtdiff
+++ b/dtdiff
@@ -1,8 +1,4 @@
-#! /bin/bash
-
-# This script uses the bash <(...) extension.
-# If you want to change this to work with a generic /bin/sh, make sure
-# you fix that.
+#! /bin/sh
DTC=dtc
@@ -35,4 +31,15 @@ if [ $# != 2 ]; then
exit 1
fi
-diff -u <(source_and_sort "$1") <(source_and_sort "$2")
+for dir in /dev/fd /proc/self/fd; do
+ if [ -d "${dir}" ]; then
+ break
+ fi
+done
+
+source_and_sort "$1" | (
+ # Duplicate current stdin from the first file to fd 3 so we can change fd 0
+ # to the second file.
+ exec 3<&0
+ source_and_sort "$2" | diff -u "${dir}/3" "${dir}/0"
+)
--
2.15.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] dtdiff: change to POSIX shell
[not found] ` <20180110054756.23464-1-vapier-aBrp7R+bbdUdnm+yROfE0A@public.gmane.org>
@ 2018-01-10 5:57 ` David Gibson
[not found] ` <20180110055718.GG19773-K0bRW+63XPQe6aEkudXLsA@public.gmane.org>
0 siblings, 1 reply; 5+ messages in thread
From: David Gibson @ 2018-01-10 5:57 UTC (permalink / raw)
To: Mike Frysinger; +Cc: devicetree-compiler-u79uwXL29TY76Z2rM5mHXA
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On Wed, Jan 10, 2018 at 12:47:56AM -0500, Mike Frysinger wrote:
> From: Mike Frysinger <vapier-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
>
> This changes from the bash-specific process substitution feature to
> reading with pipes. It relies on /dev/fd or /proc/self/fd existing.
>
> URL: https://crbug.com/756559
> Signed-off-by: Mike Frysinger <vapier-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
Yeah, sorry, replacing a dependency on a complex but widely available
shell with a much more cryptic dependency on a Linux specific feature
does not seem like a win to me.
> ---
> dtdiff | 19 +++++++++++++------
> 1 file changed, 13 insertions(+), 6 deletions(-)
>
> diff --git a/dtdiff b/dtdiff
> index 5fa772b0ab62..4d1b71756c2f 100644
> --- a/dtdiff
> +++ b/dtdiff
> @@ -1,8 +1,4 @@
> -#! /bin/bash
> -
> -# This script uses the bash <(...) extension.
> -# If you want to change this to work with a generic /bin/sh, make sure
> -# you fix that.
> +#! /bin/sh
>
>
> DTC=dtc
> @@ -35,4 +31,15 @@ if [ $# != 2 ]; then
> exit 1
> fi
>
> -diff -u <(source_and_sort "$1") <(source_and_sort "$2")
> +for dir in /dev/fd /proc/self/fd; do
> + if [ -d "${dir}" ]; then
> + break
> + fi
> +done
> +
> +source_and_sort "$1" | (
> + # Duplicate current stdin from the first file to fd 3 so we can change fd 0
> + # to the second file.
> + exec 3<&0
> + source_and_sort "$2" | diff -u "${dir}/3" "${dir}/0"
> +)
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] dtdiff: change to POSIX shell
[not found] ` <20180110055718.GG19773-K0bRW+63XPQe6aEkudXLsA@public.gmane.org>
@ 2018-02-02 4:14 ` Mike Frysinger
2018-02-02 4:35 ` Kyle Evans
0 siblings, 1 reply; 5+ messages in thread
From: Mike Frysinger @ 2018-02-02 4:14 UTC (permalink / raw)
To: David Gibson; +Cc: devicetree-compiler-u79uwXL29TY76Z2rM5mHXA
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On 10 Jan 2018 16:57, David Gibson wrote:
> On Wed, Jan 10, 2018 at 12:47:56AM -0500, Mike Frysinger wrote:
> > This changes from the bash-specific process substitution feature to
> > reading with pipes. It relies on /dev/fd or /proc/self/fd existing.
> >
> > URL: https://crbug.com/756559
> > Signed-off-by: Mike Frysinger <vapier-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
>
> Yeah, sorry, replacing a dependency on a complex but widely available
> shell with a much more cryptic dependency on a Linux specific feature
> does not seem like a win to me.
bash's <(...) only works when the host supports either /dev/fd or /proc/self/fd,
so i don't think this is less portable. /dev/fd also isn't Linux-specific.
-mike
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] dtdiff: change to POSIX shell
2018-02-02 4:14 ` Mike Frysinger
@ 2018-02-02 4:35 ` Kyle Evans
[not found] ` <CACNAnaESOk5Wb+Y1Sy2X3AuCqXFMj1QZ6_CFORTE=AcFRckM4A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
0 siblings, 1 reply; 5+ messages in thread
From: Kyle Evans @ 2018-02-02 4:35 UTC (permalink / raw)
To: David Gibson, devicetree-compiler-u79uwXL29TY76Z2rM5mHXA
On Thu, Feb 1, 2018 at 10:14 PM, Mike Frysinger <vapier-aBrp7R+bbdUdnm+yROfE0A@public.gmane.org> wrote:
> On 10 Jan 2018 16:57, David Gibson wrote:
>> On Wed, Jan 10, 2018 at 12:47:56AM -0500, Mike Frysinger wrote:
>> > This changes from the bash-specific process substitution feature to
>> > reading with pipes. It relies on /dev/fd or /proc/self/fd existing.
>> >
>> > URL: https://crbug.com/756559
>> > Signed-off-by: Mike Frysinger <vapier-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
>>
>> Yeah, sorry, replacing a dependency on a complex but widely available
>> shell with a much more cryptic dependency on a Linux specific feature
>> does not seem like a win to me.
>
> bash's <(...) only works when the host supports either /dev/fd or /proc/self/fd,
> so i don't think this is less portable. /dev/fd also isn't Linux-specific.
> -mike
For what it's worth, this isn't completely true. Bash can also use
FIFOs for process substitution [1]. FreeBSD does not use fdescfs by
default, but it can be mounted, and using fdescfs for process
substitution is provided as an optional feature in shells/bash. It
would be nice to not grow a dependency on fdescfs for dtc. =)
[1] https://www.gnu.org/software/bash/manual/html_node/Process-Substitution.html
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] dtdiff: change to POSIX shell
[not found] ` <CACNAnaESOk5Wb+Y1Sy2X3AuCqXFMj1QZ6_CFORTE=AcFRckM4A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
@ 2018-02-05 18:31 ` Mike Frysinger
0 siblings, 0 replies; 5+ messages in thread
From: Mike Frysinger @ 2018-02-05 18:31 UTC (permalink / raw)
To: Kyle Evans; +Cc: David Gibson, devicetree-compiler-u79uwXL29TY76Z2rM5mHXA
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On 01 Feb 2018 22:35, Kyle Evans wrote:
> On Thu, Feb 1, 2018 at 10:14 PM, Mike Frysinger <vapier-aBrp7R+bbdUdnm+yROfE0A@public.gmane.org> wrote:
> > On 10 Jan 2018 16:57, David Gibson wrote:
> >> On Wed, Jan 10, 2018 at 12:47:56AM -0500, Mike Frysinger wrote:
> >> > This changes from the bash-specific process substitution feature to
> >> > reading with pipes. It relies on /dev/fd or /proc/self/fd existing.
> >> >
> >> > URL: https://crbug.com/756559
> >> > Signed-off-by: Mike Frysinger <vapier-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
> >>
> >> Yeah, sorry, replacing a dependency on a complex but widely available
> >> shell with a much more cryptic dependency on a Linux specific feature
> >> does not seem like a win to me.
> >
> > bash's <(...) only works when the host supports either /dev/fd or /proc/self/fd,
> > so i don't think this is less portable. /dev/fd also isn't Linux-specific.
>
> For what it's worth, this isn't completely true. Bash can also use
> FIFOs for process substitution [1]. FreeBSD does not use fdescfs by
> default, but it can be mounted, and using fdescfs for process
> substitution is provided as an optional feature in shells/bash. It
> would be nice to not grow a dependency on fdescfs for dtc. =)
>
> [1] https://www.gnu.org/software/bash/manual/html_node/Process-Substitution.html
sorry, you're right. i didn't fully trace the bash source. that man page
matches the current sources in that either named fifos or /dev/fd are needed.
Simon suggested i just use tempfiles myself. i had avoided them because the
current method makes it easy to avoid leaks (for whatever reason), but if it
isn't a big deal, that'd be an easy fix.
-mike
TMP1= TMP2=
trap 'rm -f "${TMP1}" "${TMP2}"' EXIT
TMP1=$(mktemp)
TMP2=$(mktemp)
source_and_sort "$1" "${TMP1}"
source_and_sort "$2" "${TMP2}"
diff -u "${TMP1}" "${TMP2}"
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^ permalink raw reply [flat|nested] 5+ messages in thread
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2018-01-10 5:47 [PATCH] dtdiff: change to POSIX shell Mike Frysinger
[not found] ` <20180110054756.23464-1-vapier-aBrp7R+bbdUdnm+yROfE0A@public.gmane.org>
2018-01-10 5:57 ` David Gibson
[not found] ` <20180110055718.GG19773-K0bRW+63XPQe6aEkudXLsA@public.gmane.org>
2018-02-02 4:14 ` Mike Frysinger
2018-02-02 4:35 ` Kyle Evans
[not found] ` <CACNAnaESOk5Wb+Y1Sy2X3AuCqXFMj1QZ6_CFORTE=AcFRckM4A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2018-02-05 18:31 ` Mike Frysinger
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