Filename length limits on linux?

Solution 1:

See the Wikipedia page about file systems comparison, especially in column Maximum filename length.

Here are some filename length limits in popular file systems:

BTRFS   255 bytes
exFAT   255 UTF-16 characters
ext2    255 bytes
ext3    255 bytes
ext3cow 255 bytes
ext4    255 bytes
FAT32   8.3 (255 UCS-2 code units with VFAT LFNs)
NTFS    255 characters
XFS     255 bytes

Solution 2:

I've read here that path length limit is in system headers. File name length limit is there too. On my system it's file:


and C-lang defines:

  #define NAME_MAX         255    /* # chars in a file name */
  #define PATH_MAX        4096    /* # chars in a path name including nul */

and some more.

Solution 3:

I refer to other answers, please upvote them.

Are there any filename or path length limits on Linux?

Yes, filename and pathname lengths are limited by :

  • file-system limits as stated by WerkkreW ;
  • constants defined in linux/limits.h as stated by sfp.

To dynamically get these properties:

  • Use functions pathconf and fpathconf as proposed by Michael Aaron Safyan
  • Create a filename (or pathname) longer and longer as explained by dogbane
  • Use the command getconf as proposed by tim that is also available on Linux:

    $ getconf NAME_MAX /mnt/sda2/
    $ getconf PATH_MAX /mnt/sda3/

Solution 4:

And for the sake of saving time (and anchoring it to memory):

ext2, ext3, ext4, zfs: no pathname limits; 255 bytes filename limit.

Solution 5:

Those are file system name lengths. "linux" itself has some too. For instance, from bits/stdio_lim.h:

# define FILENAME_MAX 4096