Using ls to list directories and their total sizes

TLDR

ls does not report the total size of a directory's contents - it reports metadata about the directory entry. To get directory sizes use du (disk usage) and combine it with sort or ls-style output if you need human-readable listings. This post shows practical commands for GNU/Linux and macOS, how to list directories only, and common pitfalls to watch for.

Working at the shell you might instinctively try ls -lh to learn which directories are taking space. That leads to confusion because ls shows the directory entry size, not the sum of files inside. Use du to measure contents and then sort or format the output so it looks familiar.

Prerequisites

• A POSIX-like shell (bash, zsh).
• du and sort are available on macOS and Linux by default. GNU du (Linux) and BSD du (macOS) have slightly different flags - I show both variants below.

Quick: human-friendly directory totals (recommended)

Before the code: this lists the size of each item in the current directory and sorts them smallest to largest. It works on both macOS and Linux.

# list sizes of items in current directory, human-readable, sorted by size
# - du: estimate file space usage
# - -sh: summarize each path and print sizes in human readable form
# - *: expands to all non-hidden items
# - sort -h: sort by human-readable numbers

du -sh * 2>/dev/null | sort -h

• What this does: prints one line per entry like "4.0K ./bin" and sorts by size.
• Why it matters: quick and reliable way to see which directories (and files) use space.

Show only directories

Before the code: filter the results to directories only. This uses find to restrict to directories and du -sh to size them.

# GNU and BSD compatible: find directories at depth 1 and show their sizes
find . -maxdepth 1 -type d -print0 | xargs -0 du -sh 2>/dev/null | sort -h

• What this does: finds only first-level directories (including .), sizes them, and sorts the output.
• Why it matters: avoids listing files, which is useful if you only care about directory totals.

Recursive view with depth (GNU vs macOS)

Before the code: get sizes of top-level directories with a single command. Flags differ between GNU and BSD variants.

# GNU (Linux): show human sizes, only depth 1
du -h --max-depth=1 | sort -h

# BSD (macOS): show human sizes, only depth 1
du -h -d 1 | sort -h

• What this does: prints cumulative sizes for the current directory and its immediate children.
• Why it matters: a concise tree-like view of where space is going.

Add a familiar ls-like column layout

Before the code: if you prefer a two-column layout similar to ls -lh, transform du output to align columns.

# align columns: size and name
du -sh * 2>/dev/null | sort -h | awk '{printf "%-8s %s\n", $1, $2}'

• What this does: sorts the sizes and prints a formatted column with size then name.
• Why it matters: easier to scan when you want a neat table in scripts or notes.

Handling hidden files and permission errors

Hidden files starting with a dot are not matched by *. To include them use a shell expansion or find:

# include hidden entries (bash/zsh): dotglob on bash or use this pattern in zsh
# bash: shopt -s dotglob; du -sh * .[!.]* ..?*; shopt -u dotglob
# portable: use find at depth 1
find . -mindepth 1 -maxdepth 1 -print0 | xargs -0 du -sh 2>/dev/null | sort -h

Permissions can block du from reading subdirectories. You may see "Permission denied" messages - redirect stderr to /dev/null if you prefer a clean list, but investigate denied paths when you expect to be able to read them.

Why ls alone is misleading

• ls -ld some_dir prints the size of the directory inode - this is not the sum of files inside.
• stat also reports filesystem metadata, not recursive totals.

Example that confuses people:

# shows directory entry size, not content size
ls -ld mydir
stat mydir

If you need the contents' total, use du as shown above.

Useful scripts and aliases

Before the code: a small shell alias you can add to ~/.zshrc or ~/.bashrc for convenience.

# add to shell config (zsh or bash)
# 'ds' for directory sizes in current folder
alias ds='du -sh -- * 2>/dev/null | sort -h'

# macOS variant (BSD du uses -d)
alias ds_mac='du -h -d 1 | sort -h'

• What this does: gives a quick command ds to inspect sizes.
• Why it matters: small ergonomics change that saves time in daily work.

ASCII workflow - quick mental model

list entries -> size them with du -> sort by human numbers -> display
   |                |                      |
  shell           du(estimate)          sort -h

Short practical conclusion

Use du for directory totals and combine it with sort -h to get readable, ordered results. Use find and xargs when you want to restrict to directories or include hidden entries. Add a small alias if you run this often so you can check disk usage at a glance.

Next steps you can explore: pipe the output into monitoring scripts, use ncdu for interactive exploration, or integrate these commands into periodic disk usage reports.