Aliases and native utils name collision

We have 24 conflicting names between PS aliases and /bin, /usr/bin, etc folders

# /bin
cat              
cp               
echo             
kill             
ls               
mv               
ps               
pwd              
rm               
rmdir            
sleep
# /usr/bin
cd                     
clear                  
cpp                    
diff                   
fc                     
man                    
ri                     
sort                   
tee                    
type                   
write         
# /usr/sbin
ac
# /sbin
mount

We need to figure out what's out story about it.

I think it make sense to play around with different options to see pros and cons on practice.

Try it (the snippet is outdated, see the new snippet for 0.3.0 bellow)

You can add this snippet to your profile and easily switch from one mode to another

Remove-PSAliases will remove aliases, so you can use native utilities.
Set-PSAliases will restore aliases.

$global:__aliases = @(
    'cat',              
    'cp',               
    'echo',             
    'kill',             
    'ls',               
    'mv',               
    'ps',               
    'pwd',              
    'rm',               
    'rmdir',            
    'sleep',
    'cd',                     
    'clear',                  
    'cpp',                    
    'diff',                   
    'fc',                     
    'man',                    
    'ri',                     
    'sort',                   
    'tee',                    
    'type',                   
    'write',         
    'ac',
    'mount'
) 

function Set-PSAliases
{
    $global:__aliases | % { 
        Write-Host "Adding $_"
        Set-Alias $_ $global:__aliases_backup[$_] -Scope Global 
    }      
}

function Remove-PSAliases
{
    if (-not $global:__aliases_backup) {
        $global:__aliases_backup = @{}
        $global:__aliases | % {
            $global:__aliases_backup[$_] = (Get-Command $_).ResolvedCommandName
        }
    }

    $global:__aliases | % { 
        Write-Host "Removing $_"
        while (Test-Path alias:$_) {
            Remove-Item -Force alias:$_ 
        }
    }
}

Is this much of an issue? A user of PowerShell, I think, would expect the cmdlets to be preferred because of their object-orientedness, and the native commands can be easily accessed by absolute path or Get-Command.

Just observed that I did a look-up only in /bin, but not in other folders from PATH.
The original list of 11 indeed looks fine.

I'm worry about diff and mount.

Diff (Compare-Object) behaves very differently from what you would expect (i.e. there is no way to perform a diff in git sense of diff. Lines order is always lost).
I even wrote a normal diff tool as one of the first things for PS https://github.com/vors/PSCompareCollection

Mount is tricky for the same reason. It behaves too differently and PS version is not a true replacement.

I agree, diff and mount are worrisome because the Linux behavior is likely to be preferred by default, same goes for man.

As a user, I would expect to be forced to either remove or over-ride the default powershell aliases myself, and replace with the linux alternatives, or to use the absolute path of the external command. I don't see how this breaks down with diff and mount.

When I think thru the first time experience for somebody, who never tried powershell, but know bash

ok, now I'm here, lets get some stuff done
cd, cd, ls, wow the output looks different, I guess I can live with that.
ps, kill, yada yada, well this guys did a decent job replicating Unix utilities.
diff, wait what? What diff does? You kidding.
exit and stay away from it

In this thought experiment, the concept of aliases vs full command path even doesn't come to play.

Jeffrey Snover (@jpsnover)

From Jeffrey Snover (@jpsnover):

We need to eliminate all the PS aliases for the Linux cmds
e.g. ls needs to be the real ls, etc.
We should probably ship with a sample profile with a commented out section that redefines this for the people that want them.

For the 0.3.0 release, we will remove all the conflicting aliases.

We have a naive agreement that most of these need to be removed at build-time on just Linux, with the exception of a few that still need to be defined (e.g. cd).

That being said, there's some more thinking we have to do. One option is to create a formatter that makes the output of something like Get-Process look like the string output of '/bin/ps', and then enable it being piped to awk/sed. We have to think about it more.

The mindset for this is that it will be used as an interactive shell by Linux users.
As such we should minimize surprises.
The last time I looked ps (or ls) had like 80 switches so there is no way we are going to emulate that.

Sent from my tablet

On Apr 7, 2016, at 11:48 AM, Joey Aiello notifications@github.com wrote:

We have a naive agreement that most of these need to be removed at build-time on just Linux, with the exception of a few that still need to be defined (e.g. cd).

That being said, there's some more thinking we have to do. One option is to create a formatter that makes the output of something like Get-Process look like the string output of '/bin/ps', and then enable it being piped to awk/sed. We have to think about it more.

—
You are receiving this because you were mentioned.
Reply to this email directly or view it on GitHub

These are the native command (not Bash built-in) collisions on my Ubuntu 14.04 box.

I'll compile these out of InitialSessionState.cs. The one thing that I don't like about this approach is that it leaves users without an easy way to put them all back at once (a PowerShell experience).

But, in my opinion, all of the built-in aliases would be much better off defined in a module outside of the System.Management.Automation library to begin with. Aliases really shouldn't be built into an engine; I don't know of any other shell that does this. Bash has default aliases... defined in /etc/bashrc or your default ~/.bash_aliases etc., which lets users and distributions easily modify them.

~/PowerShell |-/ Get-Command -Type Alias | %{ which $_.Name } 
/bin/cat
/usr/bin/clear
/usr/bin/compare
/bin/cp
/usr/bin/cpp
/usr/bin/diff
/bin/dir
/bin/echo
/bin/kill
/bin/ls
/usr/bin/man
/bin/mount
/bin/mv
/bin/ps
/bin/pwd
/bin/rm
/bin/rmdir
/bin/sleep
/usr/bin/sort
/sbin/start
/usr/bin/tee
/usr/bin/write

I also had cli which was installed by Mono, and ri which was installed by rbenv. We could remove these, but there will always be some level of collision among tool names.

I had these on my OS X box:

~/PowerShell |-/ Get-Command -Type Alias | %{ which $_.Name }
/usr/sbin/ac
/bin/cat
/usr/bin/cd
/usr/bin/clear
/bin/cp
/usr/bin/cpp
/usr/bin/diff
/bin/echo
/usr/bin/fc
/bin/kill
/bin/ls
/usr/bin/man
/sbin/mount
/bin/mv
/bin/ps
/bin/pwd
/bin/rm
/bin/rmdir
/bin/sleep
/usr/bin/sort
/usr/bin/tee
/usr/bin/type
/usr/bin/write

I also had gm which is GraphicsMagick, compare which is from ImageMagick, and rp, which is a "Tool to find ROP sequences in PE/Elf/Mach-O x86/x64 binaries" and I don't know why I had it installed.

We do not currently have a compile time constant for OS X as it shares LINUX since (so far) every compile time difference has been the same. These changes do not necessarily have to be compile-time; just the current way it's written needs to be refactored to be make these runtime changes.

The only differences between the two are that OS X additionally has the ac command, and (strangely) has native commands for what are only Bash built-ins on Linux: cd, fc, and type.

This brings up an interesting point: Bash itself stomps on quite a few native commands with its own built-ins (which are not aliases, but similar). So perhaps my earlier comment on moving them all out was on an erroneous understanding.

Bash built-ins stomp on these on Linux:

~ |-/ for i in `<linux_commands`; do help $i 2&>/dev/null && echo $i; done
dir
echo
kill
pwd

And these on OS X:

~ |-/ for i in `<osx_commands`; do help $i 2&>/dev/null && echo $i; done
cd
echo
fc
kill
pwd
type

I am of the opinion to mirror Bash and let PowerShell stomp on these as well, as that would be what Linux users (possibly unknowingly) expect.

I'm surprised kill is in the list of bash stomped commands. What's the reason for that?
On the other hand, why cd is not in Linux, but it is in OS X?

My guess is that kill is stomped so that kill in Bash can deal with Bash jobs properly. I am unsure of the history leading to why BSD but not Linux has a native command for cd.

removing the alias for cd isn't going to work very well - it's a shell built-in (even if it does exist in the filesystem)

Yes, we should keep the aliases that Bash already had as built-ins, including those that have native executables.

Remove conflicting aliases for Linux and OS X

Here is a snippet to resurrect aliases in 0.3.0

$global:__aliases = @{
#ri                             = "Remove-Item"      
diff                           = "Compare-Object"   
#echo                           = "Write-Output"     
#kill                           = "Stop-Process"     
ps                             = "Get-Process"      
tee                            = "Tee-Object"       
#type                           = "Get-Content"      
ac                             = "Add-Content"      
rm                             = "Remove-Item"      
write                          = "Write-Output"     
rmdir                          = "Remove-Item"      
#clear                          = "Clear-Host"       
mount                          = "New-PSDrive"
man                            = "help"             
#cd                             = "Set-Location"     
#fc                             = "Format-Custom"    
cpp                            = "Copy-ItemProperty"
sort                           = "Sort-Object"      
cat                            = "Get-Content"      
cp                             = "Copy-Item"        
sleep                          = "Start-Sleep"      
ls                             = "Get-ChildItem"    
#pwd                            = "Get-Location"     
mv                             = "Move-Item" 
}

function Set-PSAliases
{
    $global:__aliases.Keys | % { 
        Write-Host "Adding $_"
        Set-Alias $_ $global:__aliases[$_] -Scope Global 
    }      
}

function Remove-PSAliases
{
    $global:__aliases.Keys | % { 
        Write-Host "Removing $_"
        while (Test-Path alias:$_) {
            Remove-Item -Force alias:$_ 
        }
    }
}

TIL, which is a built-in command in zsh, but not in bash.
It leads to a weird flow:

bash-3.2$ which time
/usr/bin/time

But really time is a built-in keyword.

And even worse, it has a different parameters from an util one.

/usr/bin/time -l sleep 10

Is the same as

time sleep 10

And note, there is no -l.

http://stackoverflow.com/a/19237170/1355726

Remove conflicting aliases for Linux and OS X

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Aliases and native utils name collision #567

Try it (the snippet is outdated, see the new snippet for 0.3.0 bellow)

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Aliases and native utils name collision #567

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Try it (the snippet is outdated, see the new snippet for 0.3.0 bellow)

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andyleejordan commented on Feb 21, 2016

vors commented on Feb 21, 2016

andyleejordan commented on Feb 22, 2016

zach-folwick commented on Mar 2, 2016

vors commented on Mar 2, 2016

andyleejordan commented on Mar 23, 2016

andyleejordan commented on Apr 2, 2016

joeyaiello commented on Apr 7, 2016

jpsnover commented on Apr 7, 2016

andyleejordan commented on Apr 8, 2016

andyleejordan commented on Apr 8, 2016

andyleejordan commented on Apr 8, 2016

andyleejordan commented on Apr 8, 2016

vors commented on Apr 8, 2016

andyleejordan commented on Apr 8, 2016

JamesWTruher commented on Apr 8, 2016

andyleejordan commented on Apr 8, 2016

vors commented on Apr 12, 2016

vors commented on Apr 12, 2016

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