bug#81542: ['stat' command] Permission bits in octal not displayed in four-digit format when invoked with 'stat -c %a'

[Pádraig Brady]

On 03/08/2026 11:44, Ricky Tigg wrote:

coreutils v. 9.11

Hello. Permission bits in octal not displayed in four-digit format when
invoked with 'stat -c %a' unlike it does with 'stat' alone.

manual STAT(1)

"The valid format sequences for files (without --file-system):

  %a  permission bits in octal (see '#' and '0' printf flags)"

note: command filtered

$ stat /etc/{shadow,passwd}
  File: /etc/shadow
Access: (0000/----------)  Uid: (0/root)   Gid: (0/root)

  File: /etc/passwd
Access: (0644/-rw-r--r--)  Uid: (0/root)   Gid: (0/root)

Four-digit permission bits in octal.

$ stat -c '%a/%A %u/%U %g/%G %n' /etc/{shadow,passwd} | column -t
0/----------    0/root  0/root  /etc/shadow
644/-rw-r--r--  0/root  0/root  /etc/passwd

Not four-digit permission bits in octal. In the worse case it is not even
three-digit permission bits in octal.

Expected: Permission bits in octal displayed in four-digit format when
invoked with 'stat -c %a' like it does with 'stat' alone.

Well we give configurability when using format chars,
through the mentioned '0' and '#' flags.  See:
https://github.com/coreutils/coreutils/commit/a0c5313d6

E.g.:

  $ stat -c '%a %04a %#a %#03a' /etc/shadow .
  0 0000 0 000
  711 0711 0711 0711

I'm not sure it's worth changing the default at this stage.

Padraig