@Gil, weren't you going to try a mkdir wombat/cd wombat endless loop and see 
where it failed?

What happens if you make ~the maximum length path (~1024?) and then mount it on 
some mount point?

It seems like any "opt-in" for a longer path name would want to be program by 
program (again, analogous to long parms) because I as a vendor would have no 
control over whether a customer did a "global" opt-in in PARMLIB. (I would just 
get the "it blew up" ticket.)

Charles


-----Original Message-----
From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf 
Of Paul Gilmartin
Sent: Friday, December 4, 2020 7:02 AM
To: [email protected]
Subject: Re: C macro for maximum path length?

It would be a courtesy to leave a citation when appending to a thread.
A reader might wish to refer to the <snip>ped text.

On Fri, 4 Dec 2020 08:19:34 -0500, Peter Relson wrote:

><snip>
>The real question is not "how long can a path be [today]?" but rather "how 
>long might a path be at any future point when this compilation is 
>running?" 
></snip>
>
>And that's why z/OS will never change the maximum path length by default 
>(I actually thought it was 1024, but my knowledge is only from what 
>CSVQUERY implemented and documents for returning the path name). There 
>would have to be some sort of "opt-in" for a longer name.
>
Why, then, does z/OS not provide the POSIX-required and safe "allocating" 
form of realpath()?

Are any other utilities/functions affected?

Is it IBM's uniform policy never to relax any limit because a suitably
mischievous (or stupid) programmer might leverage it into an exposure?

How does this cover:
o NFS, where IBM can't control the content of the guest filesystem?
o The possibility that administrators might mount a tower of
  filesystems to a height beyond the putative hard-coded PATH_MAX
  ("putative" in that the value is mentioned in (obsolete?) M&C but
  no macro is defined)?

Study: https://eklitzke.org/path-max-is-tricky

----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to [email protected] with the message: INFO IBM-MAIN

Reply via email to