Cross-Platform Guide

Ps-bash targets identical command syntax across all three platforms. Under the hood, each platform uses different OS primitives. This page documents where behavior diverges and how ps-bash bridges the gaps.

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File Permissions

The ls -l and stat commands display Unix-style permission strings (rwxr-xr-x) on every platform, but the source of truth differs.

Linux / macOS

Get-BashFileInfo reads the real POSIX mode via .NET’s UnixFileMode property and converts it to a permission string with ConvertTo-PermissionString:

$mode = [int]$Item.UnixFileMode          # real kernel mode bits
$permString = ConvertTo-PermissionString -Mode $mode   # e.g. "rwxr-xr-x"

Owner, group, and hard-link count come from a native stat call:

# Linux
& /usr/bin/stat -c '%h %U %G' $Item.FullName

# macOS (BSD stat)
& /usr/bin/stat -f '%l %Su %Sg' $Item.FullName

Windows

Windows has no POSIX mode bits. Get-BashFileInfo reads the NTFS ACL via Get-Acl and maps the first matching access rules to an approximation:

$acl = Get-Acl -Path $Item.FullName
# Check FileSystemRights: Read, Write, ExecuteFile
# Build user bits, then replicate to group and other
$permString = "$u$u$u"      # e.g. "rwxrwxrwx" or "rw-rw-rw-"

Owner and group are extracted from the ACL, stripping the domain prefix (DOMAIN\user becomes user). If ACL access fails, the function falls back to rw-r--r-- for files and rwxr-xr-x for directories.

Tip

The typed LsEntry and StatEntry objects carry the same properties on every platform. Only the precision of Permissions, LinkCount, Owner, and Group varies.

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Process Listing (ps)

The ps command returns identical column names (PID, User, TTY, Stat, Command, etc.) on all platforms, but the data sources differ significantly.

Linux

Get-LinuxProcEntry reads the /proc filesystem directly:

Data	Source
PID, PPID, state, CPU ticks	/proc/[pid]/stat
UID (resolved to username)	/proc/[pid]/status + /usr/bin/getent passwd
Command line	/proc/[pid]/cmdline (null-byte separated)
Memory	/proc/meminfo for total, RSS from stat
TTY	Decoded from tty_nr (major/minor device numbers)

TTY values are real device names like pts/0 or tty1. The Stat column reflects the kernel process state character (S, R, D, Z, etc.).

Windows

Get-DotNetProcEntry uses .NET System.Diagnostics.Process plus WMI:

Data	Source
PID, process name, memory	System.Diagnostics.Process
PPID, command line, owner	Win32_Process via Get-CimInstance
Total memory (for %MEM)	Win32_OperatingSystem.TotalVisibleMemorySize
TTY	Session ID mapped to con1, con2, etc.

TTY shows con1 (console session 1) instead of Unix-style pts/0. The Stat column is inferred: Sl for multi-threaded, S otherwise.

macOS

macOS also uses Get-DotNetProcEntry but supplements with the native ps command:

& /bin/ps -o user=,ppid=,tty= -p $pid

This provides real username, PPID, and TTY values. Total memory comes from sysctl -n hw.memsize. TTY values use native names (e.g. ttys001) or ? for daemon processes.

Column availability comparison

Column	Linux	macOS	Windows
PID	/proc	.NET	.NET
PPID	/proc	/bin/ps	WMI
User	/proc + getent	/bin/ps	WMI or $env:USERNAME
TTY	device decode	/bin/ps	session ID
Stat	kernel state	inferred	inferred
VSZ / RSS	/proc	.NET	.NET
Command	/proc/cmdline	process name	WMI CommandLine

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Symlinks (ln -s)

Linux / macOS

Symbolic and hard links work without restrictions:

ln -s target linkname        # symbolic link
ln target linkname           # hard link
ln -sf target linkname       # force-replace existing

Windows

Symbolic links require elevated privileges:

• Developer Mode enabled (Settings > Update & Security > For developers), or
• Running PowerShell as Administrator

Hard links work without elevation but the target must be a file on the same NTFS volume.

The test suite skips all 5 symlink tests on Windows:

It 'ln -s creates symbolic link' -Skip:$IsWindows { ... }

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Native Command Resolution

Ps-bash calls native executables by absolute path on Unix platforms to avoid alias recursion.

Linux / macOS

When ps-bash needs native OS data it cannot get through .NET alone, it calls the real binary directly:

Command	Path
stat	/usr/bin/stat
getent	/usr/bin/getent (Linux only)
ps	/bin/ps (macOS only)
id	/usr/bin/id
sysctl	/usr/sbin/sysctl (macOS only)

Using absolute paths prevents infinite recursion when the user has aliased stat to Invoke-BashStat or similar.

Windows

Windows has no native stat, ls, ps, or id commands. All data comes from .NET APIs and WMI:

Unix equivalent	Windows source
stat	Get-Item + Get-Acl
ls	Get-ChildItem + Get-Acl
ps	Get-Process + Get-CimInstance Win32_Process
id -un	$env:USERNAME

No native binary calls are needed on Windows.

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stat Format Strings

The stat -c format specifiers work identically across all platforms:

Specifier	Meaning	Linux/macOS	Windows
%s	Size in bytes	exact	exact
%a	Octal permissions	real mode	approximated from ACL
%A	Permission string	real mode	approximated from ACL
%n	File name	exact	exact
%N	Full path	exact	exact
%U	Owner name	real	from ACL
%G	Group name	real	from ACL
%i	Inode number	real	always 0
%b	Block count	real	calculated from size
%d	Device number	real	derived from drive letter
%Y	Mtime (epoch)	exact	exact
%h	Hard link count	real	always 1

Note

On Windows, inode is always 0 and device is derived from the drive letter (C: = 2, D: = 3, etc.). Block count is calculated as ceil(size / 512). The test suite validates these platform-specific behaviors with conditional tests.

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Path Handling

Forward-slash normalization

All ps-bash commands accept both / and \ as path separators on every platform. When producing BashText output, backslashes are normalized to forward slashes for bash-style display:

$bashLink = $linkName -replace '\\', '/'

This normalization happens in verbose output for cp, mv, ln, mkdir, rmdir, find, and cat error messages.

Tilde expansion

PowerShell handles ~ expansion natively via its provider system, so ls ~/Documents works on all platforms without ps-bash needing custom logic. The find command resolves the home directory via [System.Environment]::GetFolderPath('UserProfile') when building search roots.

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CI Matrix

The GitHub Actions workflow (.github/workflows/ci.yml) tests every commit on all three platforms:

strategy:
  matrix:
    os: [windows-latest, ubuntu-latest, macos-latest]
  fail-fast: false

The test suite contains 751 test cases. Platform-conditional skips handle OS-specific limitations:

Test category	Linux	macOS	Windows
Symlink tests (5 tests)	run	run	skipped
stat Linux inode test	run	skipped	skipped
stat Windows device test	skipped	skipped	run
All other tests	run	run	run

All non-skipped tests pass on every platform. Skipped tests are marked with Pester’s -Skip: parameter tied to platform detection variables ($IsWindows, $IsMacOS, $IsLinux).