Re: [PATCH] \e in echo and printf builtins
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. From a6e6e7b6f3a725b4ca0514f22e9ee4cfe2c225e2 Mon Sep 17 00:00:00 2001 From: Adam Borowski kilob...@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 kilob...@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
Re: [PATCH] \e in echo and printf builtins
Adam Borowski kilob...@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 -- To unsubscribe from this list: send the line unsubscribe dash in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] \e in echo and printf builtins
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 signature.asc Description: OpenPGP digital signature
Re: [PATCH] \e in echo and printf builtins
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 -- To unsubscribe from this list: send the line unsubscribe dash in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH] \e in echo and printf builtins
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? From a6e6e7b6f3a725b4ca0514f22e9ee4cfe2c225e2 Mon Sep 17 00:00:00 2001 From: Adam Borowski kilob...@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 kilob...@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
