From: Harald van Dijk <harald@gigawatt.nl>
To: dash <dash@vger.kernel.org>
Subject: [PATCH] Fix variable assignments in function invocations
Date: Fri, 09 Jan 2015 18:17:42 +0100 [thread overview]
Message-ID: <54B00D36.7070707@gigawatt.nl> (raw)
[-- Attachment #1: Type: text/plain, Size: 1637 bytes --]
Hello all,
A long-standing problem with dash has been how it deals with variable
assignments in function invocations, and several packages are affected
by it, two I've come across recently being autogen and pkg-config (only
their test suites, luckily).
A short test script:
f() {
echo inside f, VAR is $VAR
sh -c 'echo inside sh called from f, VAR is $VAR'
}
VAR=value f
echo after returning from f, VAR is $VAR
Assuming VAR was not already set, this should print (and does with bash):
inside f, VAR is value
inside sh called from f, VAR is value
after returning from f, VAR is
With dash, this actually prints:
inside f, VAR is value
inside sh called from f, VAR is
after returning from f, VAR is value
The first problem with that is that VAR does not get exported, the
second is that VAR's assigned value is kept after the function has returned.
Quoting SUSv4 Shell Command Language 2.9.1 Simple Commands:
If no command name results, variable assignments shall affect the
current execution environment. Otherwise, the variable assignments
shall be exported for the execution environment of the command and
shall not affect the current execution environment (except for
special built-ins).
In `VAR=value f`, f is found as the command name. No exception is made
for function invocations, so I believe this disallows dash's current
behaviour, and requires it to print the same thing bash does.
Fixing this seems trivial, see the attachment, and the test suites of
both autogen and pkg-config pass with this change. Does this look correct?
Cheers,
Harald van Dijk
[-- Attachment #2: funcvars.patch --]
[-- Type: text/plain, Size: 236 bytes --]
--- a/src/eval.c
+++ b/src/eval.c
@@ -875,7 +875,7 @@ raise:
break;
case CMDFUNCTION:
- poplocalvars(1);
+ listsetvar(varlist.list, VEXPORT|VSTACK);
if (evalfun(cmdentry.u.func, argc, argv, flags))
goto raise;
break;
next reply other threads:[~2015-01-09 17:17 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-09 17:17 Harald van Dijk [this message]
2015-01-09 17:39 ` [PATCH] Fix variable assignments in function invocations Eric Blake
2015-01-09 17:55 ` Harald van Dijk
2015-01-09 19:36 ` Chet Ramey
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=54B00D36.7070707@gigawatt.nl \
--to=harald@gigawatt.nl \
--cc=dash@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).