Dug a little deeper: On linux, PATH_MAX is 4095; on Solaris it's 1024.
In message <[EMAIL PROTECTED]>, "Eric D. Friedma n" writes: : : This sounds like a bug that should be fixed in tramp, not in JDE. : : Directory *entry* length maximums are file system dependent too, which : means that a correct implementation of this hack would require looking at : the different filesystems that can be mounted on unix and windoze (both of : which can be nfs clients, of course, and so can mount other filesystems : through NFS or natively). A quick look at the header files on my linux : machine (which includes ufs_fs.h known to work with Solaris and HP/UX, : as well as ext{2,3}_fs.h, reiser_fs.h etc.) shows that 255 is a popular : (smile) maximum length for directory entries. : : If the question being asked is "what's the longest legal *path* name" -- : well, on unix that can be very, very large. I don't know how big exactly, : but you can definitely create paths that are much bigger than the thread : below would allow. To illustrate: I ran this script on my linux machine : (ext2 filesystem). Starting at /home/eric, it happily created a directory : structure /home/eric/0/1/2/3/../4096. Note also that it had no trouble : traversing the structure as it went. Note also that each of the nodes : in this path *could* have been up to 255 characters long. In sum, : (255 * 4097) > 100. : : Obviously this is an edge case (although anyone with ClearCase experience : knows that you can end up dealing with some mighty big pathnames once : you start poking around in mvfs' "view extended pathnames"), but I : think it shows why it would be better to solve this problem through some : other means. Perhaps the original poster could describe the specific : issue with tramp in more detail? Perhaps the folks on the tramp mailing : list could be enlisted to help resolve it? : : #!/usr/bin/perl : : for my $n (0 .. 4096) { # upper limit chosen at random (note: *inclusive*) : system 'mkdir', "$n"; : if ($?) { exit 1; } : chdir $n; : } : : In message <[EMAIL PROTECTED]>, Paul Kinnucan writ >es : : : : : : Can anyone help with the question raised in the following : : thread? : : : : Paul : : : : Jose M Vidal writes: : : > : : > Yup, 100 is a hack that works for me. I don't know what the actual : : > maximums are. : : > : : > On the other hand, we just need to pick a number bigger than the most : : > unreasonably long file name but smaller than infinity. Hmmmm. What is : : > 1024? : : > : : > Sorry, : : > Jose : : > : : > : : > On Mon, 22 Oct 2001, [EMAIL PROTECTED] wrote: : : > : : > > Jose M Vidal writes: : : > > > : : > > > jde 1.17 will not work with tramp because of the way it keeps : : > > > trying to go up the directory hierarchy assuming ange-ftp : : > > > usage. It would get into an infinite loop. I fixed this by simply : : > > > constraining the length of the directory to 100 characters. I : : > > > think this makes the code much : : > > : : > > Hi Jose, : : > > : : > > Why did you choose 100 characters? How do you know that there won't : : > > be a valid path somewhere that is more than 100 characters. : : > > I'm very leery of hacks like this based on someone's estimate : : > > of what is a "reasonable" maximum for some value. I'd rather have : : > > the maximum be greater than the maximum of the maximum paths : : > > supported by Windows and Unix. Is there such a maximum? I vaguely : : > > recall reading somewhere that the limit for Windows paths is : : > > 256 characters. If Unix and Windows have constraints on path sizes, : : > > I'd be much more comfortable adopting this hack. : : > > : : > > - Paul : : > > : : > > > more robust. Here is the changed function (from jde.el): : : > > > : : > > > : : > > > (defun jde-find-project-file (dir) : : > > > "Finds the next project file upwards in the directory tree : : > > > from DIR. Returns nil if it cannot find a project file in DIR : : > > > or an ascendant directory." : : > > > (let ((file (find jde-project-file-name : : > > > (directory-files dir) :test 'string=))) : : > > > (if file : : > > > (expand-file-name file dir) : : > > > (if (< (length dir) 100) : : > > > (if (not (jde-root-dir-p dir)) : : > > > (jde-find-project-file (concat dir "../"))))))) : : > > > : : > > > Cheer, and thanks for a *great* product, : : > > > Jose : : > > > : : > > > -- : : > > > Jose M. Vidal <[EMAIL PROTECTED]> http://jmvidal.cse.sc.edu : : > > > University of South Carolina http://www.multiagent.com : : > > > : : > : : > -- : : > Jose M. Vidal <[EMAIL PROTECTED]> http://jmvidal.cse.sc.edu : : > University of South Carolina http://www.multiagent.com : : > : : :
