[PATCH setup 0/3] Setup replacement for incver_ifdep
Jon Turney
jon.turney@dronecode.org.uk
Fri Jan 29 14:22:00 GMT 2016
On 28/01/2016 20:22, Eric Blake wrote:
> On 01/28/2016 01:17 PM, Ken Brown wrote:
>>>> install-info $f /usr/share/info/dir ||
>>>> install-info --entry="* $$f ($f): $$f" $$f /usr/share/info/dir
>>>>
>>>> First, what do those double dollar signs mean?
>>>
>>> If this is from a Makefile snippet, it says that $f is a make variable,
>>> while $$ turns into a literal $f for the shell that make invokes
>>
>> It's not a Makefile snippet; it's a snippet from a bash shell script. Here's more context:
>>
>> for f in /usr/share/info/*; do
>> case "$f" in
>> *\**)
>> ;;
>> */dir|*/dir.info*)
>> ;;
>> *-[0123456789]*)
>> ;;
>> *)
>> install-info $f /usr/share/info/dir ||
>> install-info --entry="* $$f ($f): $$f" $$f /usr/share/info/dir
>> ;;
>> esac
>> done
>>
>> It looks to me like all those double dollar signs will just get expanded to the PID of the bash process, so that the second install-info command is nonsense. But maybe I'm missing something.
>
> Oooh, scary. Yeah, it looks like utter nonsense, as that would indeed
> give the PID of bash followed by a literal f, but who wants to look up
> info of '1234f'? I wonder if someone writing the script copied
> incorrectly from a Makefile?
Crazy. I didn't add this part, so I guess it's been there for a long time.
>> Second, why is the second line needed, i.e., under what circumstances
>> would it be expected to succeed after the first install-info command
>> failed?
>
> Sadly, I don't know install-info enough to answer that one.
I think the first install-info command would fail if the .info file is
missing a START-INFO-DIR-ENTRY/END-INFO-DIR-ENTRY block, in which case
install-info should fail with a 'install-info: warning: no info dir
entry in `xxx.info''
Since such a .info file is apparently valid (although I don't think we
have any instances of such), I guess the nonsense after the || should be
fixed to use '$f' correctly.
More information about the Cygwin-apps
mailing list