[OpenWrt-Devel] [PATCH v4] base-files: add /etc/profile.d support

[edgar.soldin at web.de]

On 04.09.2015 13:55, Karl Palsson wrote:
> Jo-Philipp Wich <jow at openwrt.org> wrote:
>> Hi.
> 
>>> Why the -e?  You only got existing files in the glob above right? 
> 
>> Almost. If the directory does not exist or is empty then the glob
>> pattern is returned literally, e.g. "echo /tmp/*" will expand to a list
>> of files but "echo /does_not_exist/*" will return "/does_not_exist/*"
>> literaly so the for-in loop will run once with the literal glob pattern
>> as argument, therefore the "-e" test is required.
> 
> So let's -d test the directory instead of -e testing every file just in
> case the directory didn't exist?
> 

On 04.09.2015 13:55, Karl Palsson wrote:
> Jo-Philipp Wich <jow at openwrt.org> wrote:
>> Hi.
>
>>> Why the -e? You only got existing files in the glob above right?
>
>> Almost. If the directory does not exist or is empty then the glob
>> pattern is returned literally, e.g. "echo /tmp/*" will expand to a list
>> of files but "echo /does_not_exist/*" will return "/does_not_exist/*"
>> literaly so the for-in loop will run once with the literal glob pattern
>> as argument, therefore the "-e" test is required.
>
> So let's -d test the directory instead of -e testing every file just in
> case the directory didn't exist?
>

http://mywiki.wooledge.org/BashPitfalls#for_i_in_.24.28ls_.2A.mp3.29
also explains why you need to test the availability of the found file. essentially shell globbing will return *.sh if no match is found. to circumvent that case you need test -e.

..ede
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