Nemo reports "0 bytes, empty document", but the file is not empty

[od4knb]

Distribution

Linux Mint Cinnamon 22.3 amd64

Package version

6.6.3

Frequency

Always

Bug description

When booting a [linuxmint-22.3-cinnamon-64bit.iso] file, using a Ventoy 1.1.11 bootloader, logged in as the default live system user "mint", and accessing "/proc/sys/fs/inotify/" using Nemo, the files:

/proc/sys/fs/inotify/max_queued_eventsrounding error
/proc/sys/fs/inotify/max_user_instances
/proc/sys/fs/inotify/max_user_watches

are reported as:

• Size: 0 bytes
• Type: Empty document
• Detailed Type: Empty document
• Octal Permissions: 100644

but these files are UTF-8 "Plain Text Document" files, and they are not empty.

Steps to reproduce

Nemo

• start Nemo file manager, as $USER "mint" (live system user account)
• go to "/proc/sys/fs/inotify/"
• check: the files "max_queued_events", "max_user_instances" and "max_user_watches" are present
• enable [menu View\List view]
• enable [menu Edit\Preferences\List columns\Detailed Type]
• enable [menu Edit\Preferences\List columns\Octal Permissions]
• check: Nemo reports on all three files:

Size: 0 bytes
Type: Empty document
Detailed Type: Empty document
Octal Permissions: 100644

• check: the properties panel of all three files, also report "size: 0 bytes"
• open all three files in Xed text editor
• check: all files contain a value
• check: the files are not empty:

file                                      contains value  value byte size
/proc/sys/fs/inotify/max_queued_events    16384           5
/proc/sys/fs/inotify/max_user_instances   128             3
/proc/sys/fs/inotify/max_user_watches     30170           5

• check: total byte size = 13 bytes (UTF-8)
• start Nemo file manager, as $USER "mint", with elevated privileges, issueing:

sudo nemo

• note: the process "nemo" now runs under account "root"
• go to "/proc/sys/fs/inotify/"
• check: Nemo reports on all three files:

Size: 0 bytes
Type: Empty document
Detailed Type: Empty document

Stat

• open Terminal
• issue command:

DirectoryToList="/proc/sys/fs/inotify" && \
stat -c "%a %N type=%F, owner=%U (UID=%u), group=%G (GID=%g)" ${DirectoryToList}/* > ~/stat.txt # visible files && \
stat -c "%a %N type=%F, owner=%U (UID=%u), group=%G (GID=%g)" ${DirectoryToList}/.* >> ~/stat.txt # hidden files

Result:

644 '/proc/sys/fs/inotify/max_queued_events' type=regular empty file, owner=root (UID=0), group=root (GID=0)
644 '/proc/sys/fs/inotify/max_user_instances' type=regular empty file, owner=root (UID=0), group=root (GID=0)
644 '/proc/sys/fs/inotify/max_user_watches' type=regular empty file, owner=root (UID=0), group=root (GID=0)

ls

• Open Terminal
• issue command:

ls -l /proc/sys/fs/inotify

Result:

total 0
-rw-r--r-- 1 root root 0 Apr 22 11:55 max_queued_events
-rw-r--r-- 1 root root 0 Apr 22 11:55 max_user_instances
-rw-r--r-- 1 root root 0 Apr 22 10:52 max_user_watches

• check: the fifth field contains the size in bytes: 0 (incorrect)
• note: "total 0" means "total size = 0 KB"
• copy the files:

/proc/sys/fs/inotify/max_queued_events
/proc/sys/fs/inotify/max_user_instances   
/proc/sys/fs/inotify/max_user_watches   

to "/home/${USER}/Documents/"

• issue command:

ls -l "/home/${USER}/Documents/"

Result:

total 12
-rw-r--r-- 1 mint mint 6 Apr 22 11:55 max_queued_events
-rw-r--r-- 1 mint mint 4 Apr 22 11:55 max_user_instances
-rw-r--r-- 1 mint mint 6 Apr 22 10:52 max_user_watches

• note: "total 12" means "total size = 12 KB" (huh? KB/KiB mixup/rounding?)
• check: the files are now not reported by nemo as "empty document":

Size: 6, 4, 6 bytes
Type: Text
Detailed Type: Plain Text Document

System

  Host: mint Kernel: 6.14.0-37-generic arch: x86_64 bits: 64 compiler: gcc
    v: 13.3.0 clocksource: tsc avail: hpet,acpi_pm
    parameters: BOOT_IMAGE=/casper/vmlinuz boot=casper
    initrd=/casper/initrd.lz uuid=6e72f523-dc09-4880-8910-93ffa64401c5
    username=mint hostname=mint quiet splash --
  Desktop: Cinnamon v: 6.6.4 tk: GTK v: 3.24.41 wm: Muffin v: 6.6.1 tools:
    avail: cinnamon-screensaver vt: 7 dm: LightDM v: 1.30.0
    Distro: Linux Mint 22.3 Zena base: Ubuntu 24.04 noble

Packages

Nemo

gir1.2-nemo-3.0/zena,now 6.6.3+zena amd64 [installed]
libnemo-extension1/zena,now 6.6.3+zena amd64 [installed]
nemo-data/zena,zena,now 6.6.3+zena all [installed]
nemo-dbg/zena,now 6.6.3+zena amd64 [installed]
nemo-emblems/zena,zena,now 6.6.0+zena all [installed]
nemo-fileroller/zena,now 6.6.0+zena amd64 [installed]
nemo-preview/zena,now 6.6.0+zena amd64 [installed]
nemo-share/zena,now 6.6.0+zena amd64 [installed]
nemo/zena,now 6.6.3+zena amd64 [installed]
python-nemo/zena,now 6.6.0+zena amd64 [installed]

Thanks in advance,
kind regards,
Odie

[Jeremy7701]

/proc is not a real file system.
The kernel makes some data available via this virtual read only file system.
So normal file size information details don't apply.