cygwin-bash compat/regression bug... startup line prob

Linda Walsh cygwin@tlinx.org
Thu May 1 18:11:00 GMT 2014


Eric Blake wrote:
> On 04/30/2014 11:57 PM, Linda Walsh wrote:
>> Eric Blake wrote:
>>> On 04/28/2014 02:43 PM, Linda Walsh wrote:
>>>
>>>>> cat bin/t.sh
>>>> #!/bin/bash -u 
>> Um... it doesn't work with 1 argument either.
> 
> Your context quoting is hard to follow. Here, you are complaining about
> a she-bang with only one argument,...
----
I think we are on two different pages.


While I had the example with -u + -x, later on in the same note,

-----
> It has something to do with the "-u" switch -- the "-x" was
> added to try to figure out why a script that had just
> #!/bin/bash -u
> died w/o executing a single line. 
-------------




> | > cat bin/t.sh
> | #!/bin/bash -u -x
> 
> which is indeed invalid usage]. 
----
Not on linux, which you say cygwin follows. *YOU* quoted it
saying:

>  On Linux, the entire string following the
>        interpreter name is passed as a single argument to the
> interpreter, and this string can include white space.
>        A maximum line length of 127 characters is allowed for the  first
>  line  in a #! executable shell script.
----------

On linux, (and, thus on cygwin?), "#!/bin/bash -u -x -a -b -c"
is passed as 1 argument to bash.  I.e. the spaces don't break things
into separate arguments on linux.  So any line up to 127 characters
is allowed and anything after the executable name is a single argument
to the end of the line (or 127 chars total).

I.e. the above is valid as well -- but it was the single "-u" switch
that doesn't work.



>>>> Also weird -- the interp line says "/bin/bash" not "/usr/bin/bash"
>>>> as the shell, so why does the error come from /usr/bin/bash?
>>> the answer to this question.
>> ---
>> ???
>> This isn't clear to me.  If I am running /bin/bash, why did the error
>> message
>> say /usr/bin/bash?
>>
> 
> Because you weren't running /bin/bash at that point in time, but
> /usr/bin/bash.  Again, you snipped the relevant portion of your original
----
No...I was... the output at the top was from "t.sh", which had
#!/bin/bash.

But the error message says /usr/bin/bash.


> mail:
> 
> | > bash t.sh
> 
> but that says to run 't.sh' using the 'bash' interpreter found first in
> your PATH
----
But that is not the first example in the email nor the one that gave
the /usr/bin/bash as the error message source.

I said later, that "bash t.sh" worked.. (as well as /bin/bash t.sh)...
it's only when invoked w/o specifying the interpreter on the command
line.  (i.e. going from the shebang line which says /bin/bash)

So why doesn't a single argument work (-u?)




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