On May 2, 2010, at 05:33 , Limestraël wrote:

Yes, it's weird, but it works! Thanks.

It's normal, actually. "~" is only understood by the shell, so unless the shell is invoked to expand it a program will fail to understand it. Additionally, some shells only expand "~" at the beginning of a "word", so if you `export PATH=~/foo:~/bar' the second "~" won't be expanded. (bash will expand it after a colon, so that should work.) If you quote the string, "~" won't be expanded (`export PATH="~/foo"' won't expand the "~"). A way to check this: type `env PATH'. If the result contains a "~", you need to look at how you're setting PATH to make sure "~" isn't being quoted. -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allbery@kf8nh.com system administrator [openafs,heimdal,too many hats] allbery@ece.cmu.edu electrical and computer engineering, carnegie mellon university KF8NH

Daniel Fischer writes:

Am Sonntag 02 Mai 2010 22:26:43 schrieb Brandon S. Allbery KF8NH:

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On May 2, 2010, at 05:33 , Limestraël wrote:

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Yes, it's weird, but it works! Thanks.

It's normal, actually. "~" is only understood by the shell, so unless the shell is invoked to expand it a program will fail to understand it.

If the default shell is bash and the PATH is set and exported in ~/.bashrc, it should work with '~' unless the string is quoted, shouldn't it? bash expands the tildes when the value is assigned to PATH, I think. That would explain why it's a relatively rare breakage.

bash expands it when you use it within bash, but when it's used within another program this might not be the case (since the PATH is just a String after all). -- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com IvanMiljenovic.wordpress.com

On 3 May 2010 08:49, Daniel Fischer wrote:

Am Montag 03 Mai 2010 00:28:31 schrieb Ivan Lazar Miljenovic:

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bash expands it when you use it within bash, but when it's used within another program this might not be the case (since the PATH is just a String after all).

But does that string contain any '~'s? I think not (unless quoted). I believe the string that is assigned to PATH is already expanded (if you have

I tried it: ivanm@feitpc02 ~ $echo $PATH ~/tools/bin/:/home/ivanm/emacs/bin/:/home/ivanm/.cabal/bin/:/home/ivanm/ghc/bin/:/usr/bin/:/home/ivanm/tools/bin/:/home/ivanm/emacs/bin/:/home/ivanm/.cabal/bin/:/home/ivanm/ghc/bin/:/usr/bin/:/home/ivanm/tools/bin/:/home/ivanm/emacs/bin/:/home/ivanm/.cabal/bin/:/usr/bin/:/home/ivanm/ghc/bin/:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games ivanm@feitpc02 ~ $ghc -e 'System.Environment.getEnv "PATH"' "~/tools/bin/:/home/ivanm/emacs/bin/:/home/ivanm/.cabal/bin/:/home/ivanm/ghc/bin/:/usr/bin/:/home/ivanm/tools/bin/:/home/ivanm/emacs/bin/:/home/ivanm/.cabal/bin/:/home/ivanm/ghc/bin/:/usr/bin/:/home/ivanm/tools/bin/:/home/ivanm/emacs/bin/:/home/ivanm/.cabal/bin/:/usr/bin/:/home/ivanm/ghc/bin/:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games" whilst variables might get expanded, ~ isn't. -- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com IvanMiljenovic.wordpress.com

On 3 May 2010 10:25, Daniel Fischer wrote:

It is by my bash:

dafis@linux-mkk1:~/Haskell> export DUMMY=~/bin:~/.cabal dafis@linux-mkk1:~/Haskell> echo $DUMMY /home/dafis/bin:/home/dafis/.cabal dafis@linux-mkk1:~/Haskell> printenv DUMMY /home/dafis/bin:/home/dafis/.cabal dafis@linux-mkk1:~/Haskell> ghc -e 'System.Environment.getEnv "DUMMY"' "/home/dafis/bin:/home/dafis/.cabal" dafis@linux-mkk1:~/Haskell> bash --version GNU bash, version 3.2.39(1)-release (i586-suse-linux-gnu) Copyright (C) 2007 Free Software Foundation, Inc.

Apparently, it's version-dependent (unsurprisingly). What's your shell?

This is on my ubuntu box at uni: ivanm@feitpc02 ~ $export DUMMY="~/bin:~/cabal" ivanm@feitpc02 ~ $echo $DUMMY ~/bin:~/cabal ivanm@feitpc02 ~ $printenv DUMMY ~/bin:~/cabal ivanm@feitpc02 ~ $bash --version GNU bash, version 3.2.48(1)-release (i486-pc-linux-gnu) Copyright (C) 2007 Free Software Foundation, Inc. ivanm@feitpc02 ~ $ So yeah, looks like it's version-specific. -- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com IvanMiljenovic.wordpress.com

On 3 May 2010 10:37, Brandon S. Allbery KF8NH wrote:

On May 2, 2010, at 20:34 , Ivan Miljenovic wrote:

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ivanm@feitpc02 ~ $export DUMMY="~/bin:~/cabal"

All bets are off when it's quoted; no shell tilde-expands quoted strings.

Oh, in that case without the quotes it works (I thought it had to be quoted for some reason... >_>). Anyway, this looks like what's causing Limestraël's problem then. -- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com IvanMiljenovic.wordpress.com

On May 2, 2010, at 18:21 , Daniel Fischer wrote:

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Additionally, some shells only expand "~" at the beginning of a "word", so if you `export PATH=~/foo:~/bar' the second "~" won't be expanded. (bash will expand it after a colon, so that should work.)

Do you perchance know which shells would expand only the first tilde?

Older zsh when MAGIC_EQUAL_SUBST isn't set. zsh 4.x handles "export" and some other builtins automatically, but MAGIC_EQUAL_SUBST is still needed in some cases, such as the occasionally suggested `echo PATH=... >>.profile'.

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A way to check this: type `env PATH'.

Shouldn't that be

It was supposed to be "printenv". *sigh*

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If the result contains a "~", you need to look at how you're setting PATH to make sure "~" isn't being quoted.

If the result contains a tilde, you're already hosed because System.Directory.findExecutable doesn't do tilde-expansion before calling doesFileExist.

Er, that's the point. -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allbery@kf8nh.com system administrator [openafs,heimdal,too many hats] allbery@ece.cmu.edu electrical and computer engineering, carnegie mellon university KF8NH