* [PATCH] \e in "echo" and "printf" builtins
@ 2014-06-28 4:56 Adam Borowski
2014-06-28 16:52 ` Harald van Dijk
0 siblings, 1 reply; 8+ messages in thread
From: Adam Borowski @ 2014-06-28 4:56 UTC (permalink / raw)
To: dash
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Hi!
I'm not sure what's your policy towards extensions, but \e as \033 is
something ubiquitous in the Unix world. C compilers (gcc, clang, icc and
tcc -- but not MSVC), perl, shells (bash and zsh -- but not dash), etc.
What about supporting it in dash as well?
Patch attached.
--
Gnome 3, Windows 8, Slashdot Beta, now Firefox Ribbon^WAustralis. WTF is going
on with replacing usable interfaces with tabletized ones?
[-- Attachment #2: 0001-Support-e-in-echo-and-printf-builtins.patch --]
[-- Type: text/x-diff, Size: 1566 bytes --]
From a6e6e7b6f3a725b4ca0514f22e9ee4cfe2c225e2 Mon Sep 17 00:00:00 2001
From: Adam Borowski <kilobyte@angband.pl>
Date: Sat, 28 Jun 2014 06:29:56 +0200
Subject: [PATCH] Support \e in "echo" and "printf" builtins.
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
---
src/bltin/printf.c | 1 +
src/dash.1 | 4 ++++
2 files changed, 5 insertions(+)
diff --git a/src/bltin/printf.c b/src/bltin/printf.c
index 893295c..98d954c 100644
--- a/src/bltin/printf.c
+++ b/src/bltin/printf.c
@@ -300,6 +300,7 @@ conv_escape(char *str, int *conv_ch)
case '\\': value = '\\'; break; /* backslash */
case 'a': value = '\a'; break; /* alert */
case 'b': value = '\b'; break; /* backspace */
+ case 'e': value = '\e'; break; /* escape */
case 'f': value = '\f'; break; /* form-feed */
case 'n': value = '\n'; break; /* newline */
case 'r': value = '\r'; break; /* carriage-return */
diff --git a/src/dash.1 b/src/dash.1
index 3847d98..7107faa 100644
--- a/src/dash.1
+++ b/src/dash.1
@@ -1199,6 +1199,8 @@ Subsequent output is suppressed. This is normally used at the end of the
last argument to suppress the trailing newline that
.Ic echo
would otherwise output.
+.It Li \ee
+Outputs an escape character (ESC).
.It Li \ef
Output a form feed.
.It Li \en
@@ -1573,6 +1575,8 @@ The characters and their meanings are as follows:
Write a \*[Lt]bell\*[Gt] character.
.It Cm \eb
Write a \*[Lt]backspace\*[Gt] character.
+.It Cm \ee
+Write an \*[Lt]escape\*[Gt] (ESC) character.
.It Cm \ef
Write a \*[Lt]form-feed\*[Gt] character.
.It Cm \en
--
2.0.0
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH] \e in "echo" and "printf" builtins
2014-06-28 4:56 [PATCH] \e in "echo" and "printf" builtins Adam Borowski
@ 2014-06-28 16:52 ` Harald van Dijk
2014-06-28 17:27 ` Adam Borowski
2014-06-28 17:33 ` Paul Gilmartin
0 siblings, 2 replies; 8+ messages in thread
From: Harald van Dijk @ 2014-06-28 16:52 UTC (permalink / raw)
To: Adam Borowski; +Cc: dash
On 28/06/14 06:56, Adam Borowski wrote:
> Hi!
>
> I'm not sure what's your policy towards extensions, but \e as \033 is
> something ubiquitous in the Unix world. C compilers (gcc, clang, icc and
> tcc -- but not MSVC), perl, shells (bash and zsh -- but not dash), etc.
>
> What about supporting it in dash as well?
> Patch attached.
Hi,
No comment on whether dash itself should accept \e, but you already
found a compiler that doesn't support it at all, and many of the ones
that do support it also (optionally) issue a warning for it. Should the
C code perhaps be using \033 instead of \e?
Cheers,
Harald van Dijk
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] \e in "echo" and "printf" builtins
2014-06-28 16:52 ` Harald van Dijk
@ 2014-06-28 17:27 ` Adam Borowski
2014-07-23 9:11 ` Adam Borowski
2014-06-28 17:33 ` Paul Gilmartin
1 sibling, 1 reply; 8+ messages in thread
From: Adam Borowski @ 2014-06-28 17:27 UTC (permalink / raw)
To: Harald van Dijk; +Cc: dash
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On Sat, Jun 28, 2014 at 06:52:51PM +0200, Harald van Dijk wrote:
> On 28/06/14 06:56, Adam Borowski wrote:
> > I'm not sure what's your policy towards extensions, but \e as \033 is
> > something ubiquitous in the Unix world. C compilers (gcc, clang, icc and
> > tcc -- but not MSVC), perl, shells (bash and zsh -- but not dash), etc.
>
> No comment on whether dash itself should accept \e, but you already
> found a compiler that doesn't support it at all, and many of the ones
> that do support it also (optionally) issue a warning for it. Should the
> C code perhaps be using \033 instead of \e?
I don't think anyone is going to ever port dash to MSVC, but you have a
point: some other new compiler can appear.
A version of the patch with \033 attached.
--
Gnome 3, Windows 8, Slashdot Beta, now Firefox Ribbon^WAustralis. WTF is going
on with replacing usable interfaces with tabletized ones?
[-- Attachment #2: 0001-Support-e-in-echo-and-printf-builtins.patch --]
[-- Type: text/x-diff, Size: 1568 bytes --]
From a6e6e7b6f3a725b4ca0514f22e9ee4cfe2c225e2 Mon Sep 17 00:00:00 2001
From: Adam Borowski <kilobyte@angband.pl>
Date: Sat, 28 Jun 2014 06:29:56 +0200
Subject: [PATCH] Support \e in "echo" and "printf" builtins.
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
---
src/bltin/printf.c | 1 +
src/dash.1 | 4 ++++
2 files changed, 5 insertions(+)
diff --git a/src/bltin/printf.c b/src/bltin/printf.c
index 893295c..98d954c 100644
--- a/src/bltin/printf.c
+++ b/src/bltin/printf.c
@@ -300,6 +300,7 @@ conv_escape(char *str, int *conv_ch)
case '\\': value = '\\'; break; /* backslash */
case 'a': value = '\a'; break; /* alert */
case 'b': value = '\b'; break; /* backspace */
+ case 'e': value = '\033'; break; /* escape */
case 'f': value = '\f'; break; /* form-feed */
case 'n': value = '\n'; break; /* newline */
case 'r': value = '\r'; break; /* carriage-return */
diff --git a/src/dash.1 b/src/dash.1
index 3847d98..7107faa 100644
--- a/src/dash.1
+++ b/src/dash.1
@@ -1199,6 +1199,8 @@ Subsequent output is suppressed. This is normally used at the end of the
last argument to suppress the trailing newline that
.Ic echo
would otherwise output.
+.It Li \ee
+Outputs an escape character (ESC).
.It Li \ef
Output a form feed.
.It Li \en
@@ -1573,6 +1575,8 @@ The characters and their meanings are as follows:
Write a \*[Lt]bell\*[Gt] character.
.It Cm \eb
Write a \*[Lt]backspace\*[Gt] character.
+.It Cm \ee
+Write an \*[Lt]escape\*[Gt] (ESC) character.
.It Cm \ef
Write a \*[Lt]form-feed\*[Gt] character.
.It Cm \en
--
2.0.0
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH] \e in "echo" and "printf" builtins
2014-06-28 16:52 ` Harald van Dijk
2014-06-28 17:27 ` Adam Borowski
@ 2014-06-28 17:33 ` Paul Gilmartin
2014-06-29 9:28 ` Harald van Dijk
2014-06-30 13:08 ` Eric Blake
1 sibling, 2 replies; 8+ messages in thread
From: Paul Gilmartin @ 2014-06-28 17:33 UTC (permalink / raw)
To: Harald van Dijk
On 2014-06-28, at 10:52, Harald van Dijk wrote:
> On 28/06/14 06:56, Adam Borowski wrote:
>>
>>
>> I'm not sure what's your policy towards extensions, but \e as \033 is
>> something ubiquitous in the Unix world. C compilers (gcc, clang, icc and
>> tcc -- but not MSVC), perl, shells (bash and zsh -- but not dash), etc.
>>
>> What about supporting it in dash as well?
>>
As a mostly passive lurker, I'm inclined to say, "No. Dash doesn't
want to become bash."
http://windtoons.com/images/Camel_-Head-Under-Tent-large.gif
OTOH, there's a POSIX requirement that builtins be indistinguishable
(except in performance) from the corresponding executables.
> No comment on whether dash itself should accept \e, but you already
> found a compiler that doesn't support it at all, and many of the ones
> that do support it also (optionally) issue a warning for it. Should the
> C code perhaps be using \033 instead of \e?
>
And here I put on my EBCDIC hat (crown of thorns) and say, "Be careful
using numeric code points; they're not portable."
-- gil
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] \e in "echo" and "printf" builtins
2014-06-28 17:33 ` Paul Gilmartin
@ 2014-06-29 9:28 ` Harald van Dijk
2014-06-30 13:08 ` Eric Blake
1 sibling, 0 replies; 8+ messages in thread
From: Harald van Dijk @ 2014-06-29 9:28 UTC (permalink / raw)
To: Paul Gilmartin; +Cc: dash
On 28/06/14 19:33, Paul Gilmartin wrote:
> On 2014-06-28, at 10:52, Harald van Dijk wrote:
>> No comment on whether dash itself should accept \e, but you already
>> found a compiler that doesn't support it at all, and many of the ones
>> that do support it also (optionally) issue a warning for it. Should the
>> C code perhaps be using \033 instead of \e?
>>
> And here I put on my EBCDIC hat (crown of thorns) and say, "Be careful
> using numeric code points; they're not portable."
The way GCC does this is to hard-code the values for ASCII, and to
hard-code the values for EBCDIC, both hidden behind preprocessor macros.
Taking that approach in dash would look something like
#if defined(ASCII)
#define ESCAPE '\033'
#elif defined(EBCDIC)
#define ESCAPE '\047'
#else
#error Unknown character set
#endif
and then use ESCAPE.
ASCII and EBCDIC would be detected (or specified) by the configure script.
But dash does have an assumption of ASCII already, which is why I didn't
think it would hurt to add one more. At the very least, it uses
hard-coded \033s in src/hetio.c, so that part of the code already cannot
be used on EBCDIC systems.
Cheers,
Harald van Dijk
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] \e in "echo" and "printf" builtins
2014-06-28 17:33 ` Paul Gilmartin
2014-06-29 9:28 ` Harald van Dijk
@ 2014-06-30 13:08 ` Eric Blake
1 sibling, 0 replies; 8+ messages in thread
From: Eric Blake @ 2014-06-30 13:08 UTC (permalink / raw)
To: Paul Gilmartin, Harald van Dijk, dash
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On 06/28/2014 11:33 AM, Paul Gilmartin wrote:
>
> OTOH, there's a POSIX requirement that builtins be indistinguishable
> (except in performance) from the corresponding executables.
The POSIX requirement only applies to portable uses of the builtin - ie.
those that are prescribed by POSIX. Since POSIX does not require \e,
dash is not failing compliance, even if it differs from extensions
provided by corresponding executables. I do not think dash needs to
bloat for \e unless POSIX standardizes it first.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] \e in "echo" and "printf" builtins
2014-06-28 17:27 ` Adam Borowski
@ 2014-07-23 9:11 ` Adam Borowski
2014-07-23 10:26 ` Jérémie Courrèges-Anglas
0 siblings, 1 reply; 8+ messages in thread
From: Adam Borowski @ 2014-07-23 9:11 UTC (permalink / raw)
To: dash
[-- Attachment #1: Type: text/plain, Size: 1099 bytes --]
On Sat, Jun 28, 2014 at 07:27:22PM +0200, Adam Borowski wrote:
> On Sat, Jun 28, 2014 at 06:52:51PM +0200, Harald van Dijk wrote:
> > On 28/06/14 06:56, Adam Borowski wrote:
> > > I'm not sure what's your policy towards extensions, but \e as \033 is
> > > something ubiquitous in the Unix world. C compilers (gcc, clang, icc and
> > > tcc -- but not MSVC), perl, shells (bash and zsh -- but not dash), etc.
> >
> > No comment on whether dash itself should accept \e, but [...]
So... can I has an answer whether dash should indeed accept \e ?
Being told "no" or "go away, we hate you" is fine, I just dislike having
patches rot forever. And not having this shorthand is annoying if you
like using colour for highlights -- it works in perl and bash, then
suddenly Oops! not in /bin/sh = dash.
Meow!
--
// If you believe in so-called "intellectual property", please immediately
// cease using counterfeit alphabets. Instead, contact the nearest temple
// of Amon, whose priests will provide you with scribal services for all
// your writing needs, for Reasonable and Non-Discriminatory prices.
[-- Attachment #2: 0001-Support-e-in-echo-and-printf-builtins.patch --]
[-- Type: text/x-diff, Size: 1568 bytes --]
From a6e6e7b6f3a725b4ca0514f22e9ee4cfe2c225e2 Mon Sep 17 00:00:00 2001
From: Adam Borowski <kilobyte@angband.pl>
Date: Sat, 28 Jun 2014 06:29:56 +0200
Subject: [PATCH] Support \e in "echo" and "printf" builtins.
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
---
src/bltin/printf.c | 1 +
src/dash.1 | 4 ++++
2 files changed, 5 insertions(+)
diff --git a/src/bltin/printf.c b/src/bltin/printf.c
index 893295c..98d954c 100644
--- a/src/bltin/printf.c
+++ b/src/bltin/printf.c
@@ -300,6 +300,7 @@ conv_escape(char *str, int *conv_ch)
case '\\': value = '\\'; break; /* backslash */
case 'a': value = '\a'; break; /* alert */
case 'b': value = '\b'; break; /* backspace */
+ case 'e': value = '\033'; break; /* escape */
case 'f': value = '\f'; break; /* form-feed */
case 'n': value = '\n'; break; /* newline */
case 'r': value = '\r'; break; /* carriage-return */
diff --git a/src/dash.1 b/src/dash.1
index 3847d98..7107faa 100644
--- a/src/dash.1
+++ b/src/dash.1
@@ -1199,6 +1199,8 @@ Subsequent output is suppressed. This is normally used at the end of the
last argument to suppress the trailing newline that
.Ic echo
would otherwise output.
+.It Li \ee
+Outputs an escape character (ESC).
.It Li \ef
Output a form feed.
.It Li \en
@@ -1573,6 +1575,8 @@ The characters and their meanings are as follows:
Write a \*[Lt]bell\*[Gt] character.
.It Cm \eb
Write a \*[Lt]backspace\*[Gt] character.
+.It Cm \ee
+Write an \*[Lt]escape\*[Gt] (ESC) character.
.It Cm \ef
Write a \*[Lt]form-feed\*[Gt] character.
.It Cm \en
--
2.0.0
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH] \e in "echo" and "printf" builtins
2014-07-23 9:11 ` Adam Borowski
@ 2014-07-23 10:26 ` Jérémie Courrèges-Anglas
0 siblings, 0 replies; 8+ messages in thread
From: Jérémie Courrèges-Anglas @ 2014-07-23 10:26 UTC (permalink / raw)
To: Adam Borowski; +Cc: dash
Adam Borowski <kilobyte@angband.pl> writes:
> On Sat, Jun 28, 2014 at 07:27:22PM +0200, Adam Borowski wrote:
>> On Sat, Jun 28, 2014 at 06:52:51PM +0200, Harald van Dijk wrote:
>> > On 28/06/14 06:56, Adam Borowski wrote:
>> > > I'm not sure what's your policy towards extensions, but \e as \033 is
>> > > something ubiquitous in the Unix world. C compilers (gcc, clang, icc and
>> > > tcc -- but not MSVC), perl, shells (bash and zsh -- but not dash), etc.
>> >
>> > No comment on whether dash itself should accept \e, but [...]
>
> So... can I has an answer whether dash should indeed accept \e ?
> Being told "no" or "go away, we hate you" is fine, I just dislike having
> patches rot forever. And not having this shorthand is annoying if you
> like using colour for highlights -- it works in perl and bash, then
> suddenly Oops! not in /bin/sh = dash.
I agree with Erik Blake, IMO there is no reason for dash to support \e
unless POSIX standardizes it first. Except if you want to encourage
unportable scripts, of course. /bin/sh is not necessarily bash or dash.
$ /bin/sh
$ type echo
echo is a shell builtin
$ echo '\033[1m hello \033[0m'
hello # (bold)
$ /bin/echo '\033[1m hello \033[0m'
\033[1m hello \033[0m
$ echo '\e[1m hello \e[0m'
\e[1m hello \e[0m
$ /bin/echo '\e[1m hello \e[0m'
\e[1m hello \e[0m
$
--
jca | PGP : 0x1524E7EE / 5135 92C1 AD36 5293 2BDF DDCC 0DFA 74AE 1524 E7EE
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2014-07-23 10:38 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-06-28 4:56 [PATCH] \e in "echo" and "printf" builtins Adam Borowski
2014-06-28 16:52 ` Harald van Dijk
2014-06-28 17:27 ` Adam Borowski
2014-07-23 9:11 ` Adam Borowski
2014-07-23 10:26 ` Jérémie Courrèges-Anglas
2014-06-28 17:33 ` Paul Gilmartin
2014-06-29 9:28 ` Harald van Dijk
2014-06-30 13:08 ` Eric Blake
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