Re: Hash-bang line length

[Chet Ramey]

On 1/13/16 8:52 AM, Ludovic Courtès wrote:
> Greg Wooledge <wooledg@eeg.ccf.org> skribis:
> 
>> On Wed, Jan 13, 2016 at 11:25:03AM +0100, Ludovic Courtès wrote:
>>> Hello,
>>>
>>> The ???READ_SAMPLE_BUF??? macro in execute_cmd.c reads at most 80 bytes from
>>> the hash-bang line.  This is less than the already-small 128-byte limit
>>> in the Linux kernel¹ and can quite easily be hit².
>>
>> That's actually much bigger than one expects for shebang handling on
>> any traditional Unix system.
> 
> Sure, but the fact that it’s smaller than that of the kernel Linux is
> problematic: when a hash-bang line > 127 chars is encountered, ‘execve’
> fails with ENOENT, so Bash’s fallback code is executed, fails as well,

No.  Since the execve fails with ENOENT, bash just prints an error
message.

> but it prints a misleading error message with an even more truncated
> hash-bang line.

Again, it's only a cosmetic issue.  I don't have a problem with increasing
the buffer size, but let's not pretend it's anything but that.

-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, ITS, CWRU    chet@case.edu    http://cnswww.cns.cwru.edu/~chet/