Linuxexit code > 0

chmod: Operation not permitted

$chmod: changing permissions of '/etc/hosts': Operation not permitted

Analysis

You are trying to change permissions of a file you don't own, or a file on a filesystem that doesn't support permissions (like FAT32/NTFS mount).

Common Triggers

  • Not the owner of the file.
  • File is immutable (chattr +i).
  • Mounted filesystem restriction.

Debug Checks

  • $Check owner: ls -l <file>.
  • $Check attributes: lsattr <file>.

Resolution

1
Use sudo.
2
Remove immutable flag: chattr -i <file>.