* bug#13815: Wrong mode for files with awkward shebang lines
@ 2013-02-25 21:56 Andrew Pennebaker
2013-02-26 2:59 ` Stefan Monnier
2013-02-26 3:02 ` Glenn Morris
0 siblings, 2 replies; 9+ messages in thread
From: Andrew Pennebaker @ 2013-02-25 21:56 UTC (permalink / raw)
To: 13815
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Some of my Scala code opens as Shell script major mode in Emacs, a problem
caused by several factors:
In order to enable dot-slashing for Scala scripts, programmers sometimes
start their code as follows:
#!/bin/sh
exec scala "$0" "$@"
!#
object Hello {
def main(args: Array[String]) {
println("Hello World!")
}
}
This is an awkward shebang line; due to the nature of shebangs, it must be
split across three lines of code, starting with #!/bin/sh.
This creates problems for Emacs, as Emacs uses `file` to detect which major
mode should be used, and `file` returns 'text/x-shellscript' when a file
begins #!/bin/sh, regardless of the file extension or programming language
content the file actually contains.
This could be solved a variety of ways, but I think the simplest is to
prioritize file extension over mimetype when a file extension is available.
We can't trust mimetypes for code that contains these awkward shebangs.
--
Cheers,
Andrew Pennebaker
www.yellosoft.us
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^ permalink raw reply [flat|nested] 9+ messages in thread
* bug#13815: Wrong mode for files with awkward shebang lines
2013-02-25 21:56 bug#13815: Wrong mode for files with awkward shebang lines Andrew Pennebaker
@ 2013-02-26 2:59 ` Stefan Monnier
2013-02-26 8:12 ` Glenn Morris
2013-02-26 3:02 ` Glenn Morris
1 sibling, 1 reply; 9+ messages in thread
From: Stefan Monnier @ 2013-02-26 2:59 UTC (permalink / raw)
To: Andrew Pennebaker; +Cc: 13815
> This could be solved a variety of ways, but I think the simplest is to
> prioritize file extension over mimetype when a file extension is available.
IIRC no strict priority will do, because for some files, the content is
more important than the filename.
> We can't trust mimetypes for code that contains these awkward shebangs.
[ FWIW Emacs doesn't actually use "mimtypes" but its own set of
file-contents-based rules. Not that it matters to this discussion,
really. ]
I think the right way is to check both file content and file name and if
the type they specify do not agree, fall back on a disambiguation
function, which should include various ad-hoc rules, and may ultimately
prompt the user if none of the ad-hoc rules resolved the ambiguity.
But in your specific case, you might get away with tweaking
inhibit-local-variables-regexps.
Stefan
^ permalink raw reply [flat|nested] 9+ messages in thread
* bug#13815: Wrong mode for files with awkward shebang lines
2013-02-26 2:59 ` Stefan Monnier
@ 2013-02-26 8:12 ` Glenn Morris
0 siblings, 0 replies; 9+ messages in thread
From: Glenn Morris @ 2013-02-26 8:12 UTC (permalink / raw)
To: Stefan Monnier; +Cc: 13815
Stefan Monnier wrote:
> IIRC no strict priority will do, because for some files, the content is
> more important than the filename.
I've never seen a real-world example where the #! line says one thing,
the filename extension says another, and the #! line is correct.
Does anyone have such an example?
(Going back to #3354, I now have 414 *.conf files in /etc, and not one
has a #! line.)
^ permalink raw reply [flat|nested] 9+ messages in thread
* bug#13815: Wrong mode for files with awkward shebang lines
2013-02-25 21:56 bug#13815: Wrong mode for files with awkward shebang lines Andrew Pennebaker
2013-02-26 2:59 ` Stefan Monnier
@ 2013-02-26 3:02 ` Glenn Morris
2021-08-23 1:13 ` Lars Ingebrigtsen
1 sibling, 1 reply; 9+ messages in thread
From: Glenn Morris @ 2013-02-26 3:02 UTC (permalink / raw)
To: Andrew Pennebaker; +Cc: 13815
Andrew Pennebaker wrote:
> #!/bin/sh
> exec scala "$0" "$@"
[...]
> This creates problems for Emacs, as Emacs uses `file` to detect which major
> mode should be used,
Emacs does not use `file', it uses interpreter-mode-alist (amongst other
things).
> This could be solved a variety of ways, but I think the simplest is to
> prioritize file extension over mimetype when a file extension is available.
It used to work that way prior to Emacs 22.1. Then it was changed for
reasons that were never properly explained IMO.
http://debbugs.gnu.org/3354
All you can do is add a mode: cookie.
Or use /usr/bin/env, IIUC
https://github.com/scala/scala/pull/9
^ permalink raw reply [flat|nested] 9+ messages in thread
* bug#13815: Wrong mode for files with awkward shebang lines
2013-02-26 3:02 ` Glenn Morris
@ 2021-08-23 1:13 ` Lars Ingebrigtsen
2021-08-23 15:06 ` Glenn Morris
0 siblings, 1 reply; 9+ messages in thread
From: Lars Ingebrigtsen @ 2021-08-23 1:13 UTC (permalink / raw)
To: Glenn Morris; +Cc: 13815
Glenn Morris <rgm@gnu.org> writes:
> It used to work that way prior to Emacs 22.1. Then it was changed for
> reasons that were never properly explained IMO.
>
> http://debbugs.gnu.org/3354
>
> All you can do is add a mode: cookie.
>
> Or use /usr/bin/env, IIUC
> https://github.com/scala/scala/pull/9
So I think the conclusion here is that this is working as designed, and
I'm closing this bug report.
--
(domestic pets only, the antidote for overdose, milk.)
bloggy blog: http://lars.ingebrigtsen.no
^ permalink raw reply [flat|nested] 9+ messages in thread
* bug#13815: Wrong mode for files with awkward shebang lines
2021-08-23 1:13 ` Lars Ingebrigtsen
@ 2021-08-23 15:06 ` Glenn Morris
2021-08-23 15:10 ` Lars Ingebrigtsen
0 siblings, 1 reply; 9+ messages in thread
From: Glenn Morris @ 2021-08-23 15:06 UTC (permalink / raw)
To: 13815
FTR, this issue would be fixed if auto-mode-alist took priority over
interpreter-mode-alist. That's how it was before Emacs 22.1.
I've never seen an explanation for why it was changed (ref bug#3354).
^ permalink raw reply [flat|nested] 9+ messages in thread
* bug#13815: Wrong mode for files with awkward shebang lines
2021-08-23 15:06 ` Glenn Morris
@ 2021-08-23 15:10 ` Lars Ingebrigtsen
2021-08-30 15:11 ` Glenn Morris
0 siblings, 1 reply; 9+ messages in thread
From: Lars Ingebrigtsen @ 2021-08-23 15:10 UTC (permalink / raw)
To: Glenn Morris; +Cc: 13815
Glenn Morris <rgm@gnu.org> writes:
> FTR, this issue would be fixed if auto-mode-alist took priority over
> interpreter-mode-alist. That's how it was before Emacs 22.1.
> I've never seen an explanation for why it was changed (ref bug#3354).
I thought it was because Debian changed the names of all their conf
files (many of which are shell scripts) to .conf?
--
(domestic pets only, the antidote for overdose, milk.)
bloggy blog: http://lars.ingebrigtsen.no
^ permalink raw reply [flat|nested] 9+ messages in thread
* bug#13815: Wrong mode for files with awkward shebang lines
2021-08-23 15:10 ` Lars Ingebrigtsen
@ 2021-08-30 15:11 ` Glenn Morris
2021-08-31 1:54 ` Lars Ingebrigtsen
0 siblings, 1 reply; 9+ messages in thread
From: Glenn Morris @ 2021-08-30 15:11 UTC (permalink / raw)
To: Lars Ingebrigtsen; +Cc: 13815
Lars Ingebrigtsen wrote:
> I thought it was because Debian changed the names of all their conf
> files (many of which are shell scripts) to .conf?
I'll repeat my earlier comments in the hope that this time someone will
read them.
I have 468 .conf files in /etc on my Debian system.
A single one (it used to be zero years ago) has a #! line.
It is nftables.conf, which contains "#!/usr/sbin/nft -f".
Emacs has no mode for "nft".
Therefore this provides zero motivation for interpreter-mode-alist to
take precedence over auto-mode-alist.
^ permalink raw reply [flat|nested] 9+ messages in thread
* bug#13815: Wrong mode for files with awkward shebang lines
2021-08-30 15:11 ` Glenn Morris
@ 2021-08-31 1:54 ` Lars Ingebrigtsen
0 siblings, 0 replies; 9+ messages in thread
From: Lars Ingebrigtsen @ 2021-08-31 1:54 UTC (permalink / raw)
To: Glenn Morris; +Cc: 13815
Glenn Morris <rgm@gnu.org> writes:
> I'll repeat my earlier comments in the hope that this time someone will
> read them.
Sorry; I misremembered. Well -- then that's not a good reason to change
this (i.e., making #! take precedence over .suffix).
Does anybody remember what the rationale was for this change? It's
somewhat puzzling behaviour.
--
(domestic pets only, the antidote for overdose, milk.)
bloggy blog: http://lars.ingebrigtsen.no
^ permalink raw reply [flat|nested] 9+ messages in thread
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-- links below jump to the message on this page --
2013-02-25 21:56 bug#13815: Wrong mode for files with awkward shebang lines Andrew Pennebaker
2013-02-26 2:59 ` Stefan Monnier
2013-02-26 8:12 ` Glenn Morris
2013-02-26 3:02 ` Glenn Morris
2021-08-23 1:13 ` Lars Ingebrigtsen
2021-08-23 15:06 ` Glenn Morris
2021-08-23 15:10 ` Lars Ingebrigtsen
2021-08-30 15:11 ` Glenn Morris
2021-08-31 1:54 ` Lars Ingebrigtsen
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