Linux and Powershell
matteoguadrini.github.io
matteoguadrini.github.io
I'm not saying it's not "better" (however you measure that) but I think it's very wordy and that's always been a turn-off and barrier of entry for me.
some examples:
pwd --> Set-Location
ls --> Get-ChildItem
cp --> Copy-Item
I totally understand how bash's sometimes seemingly random shortcuts or acronyms can ALSO be a huge barrier of entry (just as it was for me!) and the straightforwardness of Powershell is a lot clearer, but personally now that I'm "in" on the short-hand of bash, it's been hard to start using Powershell.
Kind of like I struggled with PMP exam and memorization because "Integrated Change Control Management" became "Controlled Management Change Integration" or "Managed Variation Integration" or whatever in my mind,
"Retrieve-Child-Item" vs "Get-ChildItem" or "Send-Command" vs "Invoke-Command" "Remove-Tiingamajiggy" vs "Delete-Whatchamacallit"... my mind is seemingly better equipped to memorize "obscure but unique" gobbledygook rather than "meaningful-but-generic" verbiage :|
(Probably, if I did it all the time, I'd get it right every time. Just like creating and using COBOL variables.)
PS is more powerful than Bash, it really should be faster to write a function body in it.
It's a shame because the rest of Powershell is so good.
For instance in powershell you can also do:
ls -r fooThere are (if implemented by the function), and moreover you can use just shrink the name to the point it becomes ambiguous. Your example is the same a "ls -r -i foo".
Also tab completion. You never type those out in full, no carpal tunnel, it's just "l -r" the TAB and select what you want. Discoverability is everything in PS.
However, you can always shorten parameter names as long as they remain unambiguous with other parameters, so
Get-ChildItem -Recurse -Include foo
would become ls -r -i foo
which just happens to be shorter than your 'find' example. Remove-Item -r -fo ./path/to/some/directory
Powershell is smart enough to know that -r means -Recurse and -fo means -Force because the Remove-Item cmdlet has no other parameter that starts with -r. For -f there are two possible arguments: -Filter and -Force which is why you need to be more specific with -fo.If you didn't know what it was, how would you figure out what `$(expression)` means in bash for example?
At least Bash has a very complete man-page, you can just search for `$(` there and you'll find it. But the Bash symbols all have different functions, there are (very few) operators, quotes, variables, and probably more than I can remember.
While it's not terrible, I find powershell pretty frustrating. I started off enthusiastic, especially given how archaic cmd.exe is. As mentioned elsewhere though, the advice not to use aliases, coupled with unbelievably long command names that I hate typing and can't always recall exactly - is it convert-to-csv? to-csv? no it's convertto-csv - I can never remember and I don't feel I should need to use ISE to work around this. This utterly prevents me from internalizing.
Even worse, until v3 apparently, iterating over an empty array would fail out (iterate once on $null instead of not iterating at all) and had to be protected with an explicit check. I was on v2, and it was at this point that I completely checked out and decided it wasn't worth learning and that I'd wasted my time. In general I could do what I needed with either cygwin or win32 cpython and those didn't make me feel like clawing my own eyes out.
It seems the situation has improved, but I just don't see any reason to take it up again, ESPECIALLY on linux, unless I _have to_ do dotnet stuff, and even if I do I'll explore every other available option first (ironpython? f#? is there a dotnet tcl?) TBH I avoid dotnet anyways given Microsoft's past (EEE) and current (telemetry, start menu ads, etc) behavior. Fool me once etc etc etc.
Essentially every command you'd use has a 2 or 3 character alias that is easy to remember and quick to type.
On top of it their almost programitacilly named, so if you know the powershell commands full name you can almost certainly guess the alias
Typing Get-Alias lists them all out.
https://docs.microsoft.com/en-us/powershell/module/microsoft...
Remove-Item -r -fo ./path/to/some/directory
Powershell is smart enough to know that -r means -Recurse and -fo means -Force because the Remove-Item cmdlet has no other parameter that starts with -r. For -f there are two possible arguments: -Filter and -Force which is why you need to be more specific with -fo.People don't want that, but the PowerShell Team are not moving easily to a possible-break of backwards compatibility in how the language parses variable names. It's been discussed here: https://github.com/PowerShell/PowerShell/issues/3240 for dozens of comments, and goes:
"@PowerShell/powershell-committee reviewed this one today, we have a couple thoughts: No matter what we do, we're going to do some analysis of our corpus of scripts to see how often folks use ? in variable names. Some of us have a hypothesis (that others would like to validate) that the users who are using ? in their variable names may be less advanced users (as we agree in this room we'd stay away from it because of the potential problems that could arise). On the other hand, anyone using the functionality described here will be able to understand a slightly more complicated syntax (like ${foo}?.bar). Therefore, we prefer option 3 because it avoids breaking changes on these less experienced users."
The committee ruled to keep the need for ${}, then the ternary expression became a gated experimental feature in PowerShell 7, you have to opt-in to enable it. One of the PowerShell developers analysed the PowerShell Corpus of 400k+ scripts collected by Lee Holmes and Daniel Bohannon for security threat research[2][3] and said "I found that about 62% of variables that have ? in them use it in the end. That made me lean towards not introducing a breaking change." - in the comments on a pull request[4]. Then someone else made another analysis of the corpus with regex and came up with 329 out of 22,000,000 of variables have a potentially clashing "?" at the end.
It's been reopened as another discussion[5] and another person came up with an analysis of the Corpus with proper tokenising/parsing[6] and came up with 11 variables ending in ? out of 1,896,983 unique variables used[6] which then narrowed down to 1 that might break in backwards compatibility if this change happens. Coming up 4 years of back and forth discussion, even with that kind of evidential backing, with 2 core developers, the Team Lead and Bruce Payette one of the original developers weighing in against, being brought up in a community call, then flagged for review by the committee, then reopened as a reminder again[7] the team is still not won over on the risk of breaking backward compatibility by changing ? parsing at the end of a variable name.
That is, yes "possible not forward compatible for future parameter addition", especially by third party modules who might not take it as seriously, but not at all casually by PowerShell's developers.
[2] https://www.fireeye.com/blog/threat-research/2017/07/revoke-...
[3] https://aka.ms/PowerShellCorpus (1.2GB compressed)
[4] https://github.com/PowerShell/PowerShell-RFC/pull/223#discus...
[5] https://github.com/PowerShell/PowerShell/issues/11379
[6] https://github.com/PowerShell/PowerShell/issues/11379#issuec...
PS C:\> ls -di # same as Get-ChildItem -Directory; -d would pass the -Depth parameter instead
Directory: C:\
Mode LastWriteTime Length Name
---- ------------- ------ ----
d----- 2020-07-24 18:09 PerfLogs
d-r--- 2020-12-14 22:45 Program Files
d-r--- 2020-12-24 22:57 Program Files (x86)
d----- 2020-07-23 11:29 temp
d-r--- 2020-07-24 14:19 Users
d----- 2021-01-15 21:33 Windows > ls -di # same as Get-ChildItem -Directory; -d would pass the -Depth parameter instead
Ouch, that is actually worse than I thought. So not only can you abbreviate parameters, but when the abbreviation is ambiguous Powershell just arbitrarily picks one instead of giving an error?Interactive use is different. It is write (and tweak) then use once. You never write comments in the interactive terminal. For interactive use you have aliases, plenty of them.
For PowerShell ISE there was an extension that automatically expanded all aliases, I believe for the current language server there may be similar things. If all else fails, a PowerShell script can do that as well, since PowerShell exposes its own parser in its API, so a script can easily introspect itself or another script.
That said, the PowerShell team do care about breaking backwards compatibility, so this risk is more likely in a 3rd party module than in the PS main cmdlets.
If you're just doing a quick one-off or interactively, then who cares! Crack on with your incomprehensible one-liners!
PS C:\Users\Kuinox> Get-Alias -D Get-Alias
CommandType Name Version Source
----------- ---- ------- ------
Alias gal -> Get-AliasA long time ago I spent time making alias and using custom shells but over time I just slowly reverted to default bash because it is always there and always works the same.
It used to be that some minor point might be wrong; now it's the entire comment! Premise, conclusion, everything!
Have we gotten this lazy and this overconfident that we think sounding confident is enough? That if we thought it up, it must be true? In a technical discussion? REALLY?!
...I don't want to live on this plane of existence anymore.
https://news.ycombinator.com/newsguidelines.html
Unfortunately, while accusing the parent of being completely wrong, you have not elaborated on how/why.
Would you explain the issue(s) for the parent commenter’s future reference and for those of us who don’t have a deep knowledge of PowerShell?
At this point I can't edit the comment in question, but every assumption in the comment it was a reply to was wrong. Every single one.
Aliases in powershell are not turned off by default. Aliases either exist or they don't. When speaking of aliases alone, bash is no simpler nor more complex than powershell.
By the way, this comment (the one I am writing right now) is ALSO replying to a comment written by someone who appears to be overconfident and under-informed. It's a freaking malady, and people are somehow proud of their incorrect blind guesswork.
Incorrect, blind guesswork gets a pass, because the statements made sound correct to a layman, and sound objections don't get a pass. I understand, now. I wasn't clear on how important facts are in a technical discussion.
I stated no facts in my earlier comment, that's true, but neither did the person I was replying to. I thought my point was clear. It was less clear than the comment based on false assumption, I guess.
I fucking give up. You assholes can have this.
Your two comments in this thread contain one fine, substantive statement: "Aliases in powershell are not turned off by default. Aliases either exist or they don't. When speaking of aliases alone, bash is no simpler nor more complex than powershell." If you had simply replied upthread with that in the fist place, it would have made a fine comment with a very high signal/noise ratio. Unfortunately the rest of both comments is just noise, tanking the ratio.
As I explained upthread (https://news.ycombinator.com/item?id=25862312), the internet is crazy-making this way, but it's not some property specific to HN and it's not something that's somehow changed lately. It's intrinsic to the medium, and we all need to build our skills in coping with it—which includes not reacting from a provoked place. That's not easy, but it's necessary to the sort of community we're trying for here, and we need everyone to work together on that.
The internet, including HN, is also a frustrating and activating place which triggers all sorts of untrue overgeneralizations after encountering things one dislikes: https://hn.algolia.com/?dateRange=all&page=0&prefix=true&sor...
https://news.ycombinator.com/newsguidelines.html
(Please see https://news.ycombinator.com/item?id=25862346 downthread also.)
But I guess there is a balance. Not everyone want to write matrix multiplications as A+.×B, though A%*%B seems acceptable to some, most nowadays write it as np.dot(A,B).
It does the thing where you get to cycle through various options instead of completing to the longest common prefix, which is really hard to get used to after years and years of interfaces that do the other thing.
It's also difficult to form a repertoire of common shortcuts over time because so many commands share a prefix, so most often the shortest you will be typing is 5-6 characters before you get to anything unique.
One particularly common advice with Powershell is to try PSReadLine for more bash-like versions of tab completion and other line editing things: https://github.com/PowerShell/PSReadLine
As for common shortcuts, as mentioned elsewhere in this thread, Get-Alias (and Set-Alias) is a very useful tool.
So change it:
Set-PSReadLineKeyHandler -Chord Tab -Function Complete
"Bash style completion (optional in Cmd mode, default in Emacs mode)" - https://docs.microsoft.com/en-us/powershell/module/psreadlin...1. coming up with a name that won't clash with others in already-extremely-limited namespace
2. marketing of a generically-named thing.
In the Unix world, let's take top. After top came htop. How would that play out in the Powershell world? List-Processes -> SuperDuperList-Processes?
a) it's GenericVerb-SpecificNoun usually with a name at the front of the noun like Get-YakubinComments, and you don't /have/ to adhere to it.
b) there isn't a single namespace, you can use the full name style Microsoft.PowerShell.Core\Get-Command if you want to disambiguate namespaces.
c) You can `import-module -prefix ZZ` and then all commands in that module will get your prefix at the start of the noun part, like Get-ZZYakubinComment to avoid clashes.
> "How would that play out in the Powershell world? List-Processes -> SuperDuperList-Processes?"
No because List- isn't a standard verb, nor is SuperDuperList. Get-EventLog had Get-WinEvent added. Get-WmiInstance became Get-CimInstance. The third party NTFSSecurity module added a Get-Item2 to cover for Get-Item, and a Get-NTFSAccess to cover for Get-ACL.
And because it's a shell and can run binaries, there's no problem with you having or running top and htop. or aliasing htop or calling your own thing htop, the Verb-Noun pattern isn't mandatory, it's recommended for companies developing modules so that administrators will have ideas how to list things, add things, remove things, without having to read the manual to find that it's mysterymgmtcli --auth-control -login-create instead of New-ToolUser.
PS C:\Users\Kuinox> pwd
Path
----
C:\Users\Kuinox
PS C:\Users\Kuinox> ls
Directory: C:\Users\Kuinox
Mode LastWriteTime Length Name
---- ------------- ------ ----
d----- 2020-11-30 15:39 .android
[private info redacted]
PS C:\Users\Kuinox> Get-Alias cp
CommandType Name Version Source
----------- ---- ------- ------
Alias cp -> Copy-Item
Every command you listed are default alias in ps.No, ls and cp are not aliases on Linux; the aliases which clashed too much with existing Linux commands were removed in PowerShell core, they only still exist on Windows.
PS /> get-command ls,cp
CommandType Name Source
----------- ---- ------
Application ls /bin/ls
Application cp /bin/cpJeezus.
MS technologies have sometimes been a bad investment for Windows developers too.
It seems that C# Interactive has gotten better (and since leaving that job I have switched to 100% F# for .NET stuff). But a more useful application is using Powershell to bundle a .NET class library into a flexible, low-weight, modular command line application for internal use. For instance, a C# library which does serious analytics on large data, and then a Powershell script that deals with easier annoyances like AWS authentication or FTP access, argument parsing, and so on. Obviously a real .exe is a better long-term solution but I found Powershell worked really well for rapidly sharing compiled .NET code into a tool that data scientists on my team could use.
That being said, I'll never use it on Linux as my shell. It's just too slow to start. Fish, nushell, bash, all start instantaneously, powershell (legacy and core), all take more than a second to start, on beefy machines.
I've been looking at the powershell core repo in hopes of fixing this with .net core ready to run profile, but they seemed to have something like that in place, but was disabled at that time.
Anyway, PowerShell is good, probably the best you can get on Windows(nushell also takes a bit to start, and it's still new). But, on Linux you can do much better, even if that means having to struggle with Bash/Fish scripting.
For more complex scripts a full language like Lua or Python are most likely better.
Also, last time I checked the docker container for PowerShell Core was easily over 100MB, if I remember correctly. Might work well for a dev machine, where you set it once, but for a CI, it's not ideal.
The non-core version on Windows takes ages (up to 10 seconds) to start. It's helped a bit by configuring it with -NoLogo, but still extremely slow, especially as soon as there are any modules loaded in the profile.
Every curly braces pair is a lambda function with a single parameter $_.
You can approach powershell very functionally and the abstractions work fine.
It is however a minefield of pitfalls.
Obscure error handling at the root script. Always run code at a main function that is called in the root script.
Permissive undefined variables and parameters access.
Unwinding nested attributes by referring to it at the root object level: what if you need a variable attribute from an object but the attribute collides with a built in method?
Truthy and equality are not interchangeable. -eq and Object.Equals produces vastly different results, due to the first not being type safe.
Some functions are sintactically similar to flags and parameters: -join.
Case insensitivity. Seriously...
All in all, if you are mindful of the pitfalls, use Set-StrictMode early on and don't run code at the script root, you are fine. Better than bash. A well written poweshell code is in my opinion way more readable and maintainable by than a well written bash code, despite its shortcomings.
However both of them don't come close to what python is in terms of type safety, error handling, legibility, flexibility and maintainability, even for system scripting.
A return is just an exit for the function. If you try to assign the output of a function to a variable, it will essentially be a string containing whatever is printed to the console throughout the function's duration.
function test {
"hello"
5
write-host "world"
}
$result = test
$result contains "hello",5 the output of the function and 5 is still typed as an integer - not string and not a single string - and the console prints "world".And it does this to make it work like a Unix shell, because if you write a command and get some output, then want to batch some commands together in a function and get no output except what you explicitly "return", that would be annoying.
> "functions don't actually have return statements"
They do actually have return statements (for control flow).
(And if you make classes with methods, they have traditional programming language features - called with parens, lexical scope, return statement controls the return value).
It's perennially in my "to check out" list and I haven't actually played around with it, mainly because I'm lazy and it's not in AUR.
So can't comment how ready it is to use to today. But it looks interesting.
[1] https://relational-pipes.globalcode.info/v_0/index.xhtml
While we're here I'd also like to see more experimentation on using file desciprtors with GUI/TUI tools. I've had good like using things like vim in the middle of a pipe for data that needs a human touch before being passed through. The suckless world uses dmenu quite a bit.
A structured interface introduces much more complexity. Rather than standardize on any specific 'wire' format a better approach might be to have a bi-directional connection and a standard for negotiating across it.
This might allow different forms of communication (E.G. a shared ringbuffer), negotiation of protocols, signaling when ready / blocked / needing more to proceed, what format(s) to use and if multiple streams should be used (as well as how to multiplex them)... etc. Programs might even be added to the middle to setup the preferences between two applications and then tell the OS that they're done and to just connect the input and output directly.
https://helgeklein.com/blog/2014/11/hate-powershell/
I still use CMD.exe, so please get off my lawn ;-)
When I need the power of Powershell, I use C# (or even Python + Py2Exe if I'm deploying).
Did PowerShell devs learn nothing from what was horrid about PHP?
As a developer? I haven't found PowerShell more useful than zsh/bash or fish (if you haven't, try fish, it has a lot of benefits of PowerShell (fish has its own scripting language that is more "language like", like some of the more simple constructs of Python, syntax wise) but via a simple plugin[0] you get bash compatibility too, and its made for Unix like environments). I do like that it has a rich object data model, I just don't do that kind of thing in my shell. I mostly use aliases, shortcuts, and maybe some grepping. I don't do heavy duty tasks from the command line where I'm not writing the logic in the first place, and I just find it easier to use the standard that my team does (currently, this is JavaScript, with the shebang it executes just like a binary. We can reliably say everyone has the same version of node)
Maybe in the future this will change, but I don't see the win to divide my attention economy to it deeply, personally.
The only place where I use PowerShell as a developer is in Visual Studio, in NuGet Package Manager. Update-Package, Generate-Migration, Create-Database, etc..
- Powershell is too verbose. I might as well use Python or node. Hard to beat lodash and node.js for processing objects.
- Powershell starts slow, almost 2 sec. I use i3 and it's noticeable when I start a terminal with Powershell. Sure it's a one time cost but I'm nerdy like that.
- If I work on Windows I use virtual machines or WSL2 obviating the need for a cross platform shell.
The author of this piece claims: "Powershell [...] offers a series of commands useful for developing tools and automatisms that are very difficult to implement with simple strings." but as far as I can tell, they don't go on to actually explain any of these cases where Powershell is a more appropriate tool than traditional string-based shells.
Imagine you need to get the MAC address of a network adapter in Bash. One way to do it would be...
ifconfig eth0 | grep -o -E '([[:xdigit:]]{1,2}:){5}[[:xdigit:]]{1,2}'
...another... ifconfig eth0 | awk '/^[a-z]/ { iface=$1; mac=$NF; next } /inet addr:/ { print iface, mac }'
Both of these are tied to the way the MAC address is printed in the output of the ifconfig command, and there's no contract that says that can't change. In fact, there are probably versions of it out there where these won't work. In PowerShell you would do this... Get-NetAdapter -Name Wi-Fi | select -ExpandProperty MacAddress
This is far more readable if you pass this script on to someone else, it won't break if the way it Get-NetAdapter gets rendered to the screen changes, and best of all, since I know the discoverability tricks in PowerShell, even though I've never done this before, I didn't have to go to stack overflow to find it. ip --json link show eth0 | jq '.[0].address'
I'll admit that the discovery of this is probably not very great. I wouldn't be surprised if a number of people learned about the json output, and possibly jq, from this post. ip --json address show eth0 | jq '.[0].addr_info [].local'In general when working in PowerShell you don't have to look up if there is a command with a --json flag (or equivalent) that does what you need to do, you can assume that objects are the default response and move on to working with them with PowerShell's jq equivalents. (Obviously, that makes discovery generally easy.)
Someone had to write the Get-NetAdapter cmdlet to give you a contract, and Linux has those too, so a fairer comparison would be something like:
addr=$(</sys/class/net/ens33/address)
I think that's just as readable as your example.The question is how does powershell handle extracting something without a contract, and is that more readable than bash? I'm skeptical :)
So why not compare apples to apples, how would powershell extract the MAC from ifconfig output? If that's more flexible or powerful than bash with standard UNIX tools, then that might be impressive!
It could go identically crazy as in bash, as it has its own grep (sls), can use grep itself etc.
> (ipconfig /all | sls Physical) -replace ".+: "
00-FF-84-14-66-D7
00-FF-B7-06-19-0F
00-15-5D-00-1F-3C
...Although, on more thought, it is better even as parsing engine as you have system design rules enforced across tools and OSes. Even single tool may work differently depending on *nix flavor.
ifconfig | ?{$_ -like "eth0 *"} | %{($_ -Split " ")[-1]}
In other words, find the line that starts with "eth0 ", then return the last column using " " as a delimiter.
Amusingly no, nobody wrote it. There's a part of PowerShell which can wrap WMI/CIM classes into auto-generated cmdlets, and Get-NetAdapter is one of those. (Which is why it's not available on Linux installs of PowerShell).
Take a look at the XML in C:\Windows\System32\WindowsPowerShell\v1.0\Modules\NetAdapter\ and there's no C# code or .Net DLL for it, just "MSFT_NetAdapter.cmdletDefinition.cdxml" and "MSFT_NetAdapter.Format.ps1xml". Presumably auto-generated, human checked, though I can't prove that.
[1] https://docs.microsoft.com/en-us/previous-versions/windows/d...
Grepping everything under /sys/class/net/* can't find the IP in there. It shows up in `ip addr` as venet0:0 and as a P-t-P link, so I assume that's related; doesn't work unless you know the adapter name and still might not work then? What kind of "contract" is that?
> Get-NetAdapter -Name Wi-Fi | select -ExpandProperty MacAddress
Get-NetAdapter : No MSFT_NetAdapter objects found with property 'Name' equal to 'Wi-Fi'. Verify the value of the property and retry.
At line:1 char:1
+ Get-NetAdapter -Name Wi-Fi | select -ExpandProperty MacAddress
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : ObjectNotFound: (Wi-Fi:String) [Get-NetAdapter], CimJobException
+ FullyQualifiedErrorId : CmdletizationQuery_NotFound_Name,Get-NetAdapter
I know the problem, I don't have a wireless card on this machine, but how is this different from you complaining that your network interface isn't called ens33?I don't know if they are still in vogue but /sys and /proc interfaces were originally intended to return clean output which is easy to parse in programs and scripts. I guess usage never really caught on.
The benefit of powershell - the rich object data model - isn’t actually that useful in practice day to day.
The memory usage is ridiculous for a shell.
The killer though is a disregard for economy of expression. The example in the article can be expressed as just “find /path -mtime -3”.
I have kept ps on Windows, i didn’t go back to cmd.exe there but WSL2 is still my default when opening Microsoft Terminal.
I can bring 10 - 30 instances any day in parallel without a glitch and still consuming low amount of mem. Its higher then bash, but again, bash sux and when you have 0 features compared to pwsh you can use lower amount of memory I guess. Bash is ancient, memory was much bigger problem then. Its funny that in age in electron apps we talk about memory when your todo app takes more then anything else.
> The killer though is a disregard for economy of expression.
?
> the rich object data model - isn’t actually that useful in practice day to day.
Its most useful every day feature for me.
In powershell the short syntax tends to be noisy but I usually can start with the linux commands and muddle through with tab completion:
ls -r *.swp | % { mv $_ ($_.FullName -replace ".swp$", ".swap") }This is like... AutoCAD before the year 2000. It was digital paper, and acted exactly like a drafting board with pens, rulers, and protractors. It was better than paper, but not by much! SolidWorks came out and blew it away. It was proper 3D, with constructive solid modelling. It could generate drawings of arbitrary projections or cross sections in under a second, saving months of time. Yet... people complained the same way. What if I need drafting tools? What if I want to draw lines manually? How do I draw "just" a circle? Why do I need to define what I'm doing in 3D? Just give me digital paper! That's what I want!
I made a comment on YC News nearly a year ago that I'm going to partially repeat below: https://news.ycombinator.com/item?id=23257776
PowerShell is more UNIX than UNIX.
Seriously. In UNIX, if you want to sort the output of "ps"... sss... that's hard. Sure, it has some built-in sorting capabilities, but they're not a "sort" command, this is a random addon it has accumulated over time. It can order its output by some fields, but not others. It can't do complex sorts, such as "sort by A ascending, then by B descending". To do that, you'd have to resort to parsing its text output and feeding that into an external tool. Ugh.
Heaven help you if you want to sort the output of several different tools by matching parameters. Some may not have built-in sort capability. Some may. They might have different notions of collations or internationalisation.
In PowerShell, no command has built in sort, except for "Sort-Object". There are practically none that do built in grouping, except for "Group-Object". Formatting is external too, with "Format-Table", "Format-List", etc...
So in PowerShell, sorting processes by name is simply:
ps | sort ProcessName
And never some one-character parameter like it is in UNIX, where every command has different characters for the same concept, depending on who wrote it, when, what order they added features, what conflicting letters they came across, etc...UNIX commands are more an accident of history than a cohesive, coherent, composable design. PowerShell was designed. It was designed by one person, in one go, and it is beautiful.
The acid test I give UNIX people to see if they really understand how weak the classic bash tools they use is this:
Write me a script that takes a CSV file as an input, finds processes being executed by users given their account names and process names from the input file, and then terminates those processes. Export a report of what processes were terminated, with ISO format dates of when the processes were started and how much memory they used into a CSV sorted by memory usage.
Oh, there's a user called "bash", and some of the CSV input fields may contain multiple lines and the comma character. (correctly stored in a quoted string, of course!)
This kind of thing is trivial in PowerShell. See if you can implement this, correctly in bash, such that you never kill a process that isn't in the input list.
Give it a go.
...
After I posted the above, "JoshuaDavid" provided a correct Bash solution, which blew my mind because I just assumed it was borderline impossible: https://news.ycombinator.com/item?id=23267901
Note how complex his solution is, and that he had to resort to using "jq" to convert the output of "ps" to JSON for the processing!
Compare to the solution in PowerShell, of which nearly half is just sample data: https://news.ycombinator.com/item?id=23270291
Clear, readable, and easy to modify even for a junior tech.
What I didn't say in that thread was this: I didn't actually bother to work out the solution to my toy problem in PowerShell before JoshuaDavid posted his solution.
I made up the problem simply assuming that it's ludicriously difficult in bash -- without checking -- and I similarly assumed that it's trivial in PowerShell -- without bothering to check.
I was that confident.
Are you still that confident that Bash is superior to PowerShell? Or have you internalised its constraints, and are too used to drawing fiddly little lines on digital paper to realise that your tooling is hopelessly outmatched by solid modelling?
bash set -e.(really really miss this)
Find it hard to set a script to abort with a stack trace.
Find it hard to deal with relative imports(this script imports a file in the same folder)
explaining the scoping rules
Disklike explains how your array is now a single object when you returned it from a function
Absolutely love powershell JSON support, miss native yaml support.
Love parameter globing
Love integration of parameters with a script, dislike that auto generated help can’t be done via single line comment to function
Set-PSBreakpoint -Command Write-Error -Action { break; }
similarly: trap { <# IDE breakpoint here #> }
> Find it hard to set a script to abort with a stack trace. $script:ErrorActionPreference = 'Stop'
# or
throw "Oops!"
> Find it hard to deal with relative importsThat's a very unfortunate limitation that I've never understood myself, to be honest. The typical "best practice" is to not use relative imports, but to use "installed" modules or scripts instead.
> explaining the scoping rules
https://docs.microsoft.com/en-us/powershell/module/microsoft...
> Disklike explains how your array is now a single object when you returned it from a function
This is also "one of those irritations" that tends to bite people when dealing with search results, e.g.: "Get-ADUser". If you always want an array (even an empty or single-valued array) then wrap functions in @(...), e.g.:
$users = @( Get-ADUser -Filter ... )
This is also the syntax to create an empty array, or an array of one item: $empty = @()
$listOfOne = @( 'foo' )
> miss native yaml supportBut this would be trivial to add. Writing a module to provide commandlets such as "ConvertFrom-Yaml" and "ConvertTo-Yaml" is about a day of effort in PowerShell. Good luck doing the same thing in Bash and producing something useful, let alone full-featured!
In fact, someone has done it:
https://github.com/cloudbase/powershell-yaml
> auto generated help can’t be done via single line comment to function
Two lines for automatically generated help is one too many?
# .SYNOPSIS
# This works...
echo 'foo' Set-PSBreakpoint -Command Write-Error -Action { break; }
cmd.exe /c "exit 1"
echo "if this->($LASTEXITCODE) is 1 I shouldn't be here"
Your stack trace code is wrong. What your code is doing is essentially saying throw an exception when you encounter an error. All I am asking is when exception hits the top, dump the stack trace. $script:ErrorActionPreference = 'Stop'
function bar() {
throw "oops"
}
function foo() {
$a = 123
bar
}
foo
PS C:\tmp> .\a.ps1
Exception: C:\tmp\a.ps1:6:5
Line |
6 | throw "oops"
| ~~~~~~~~~~~~
| oops
I use `trap{$_.ScriptStackTrace; break}` but unfortunately I cannot hide this code into a helper script that I can dot source... because of scoping rules! Even though I am dot sourcing a file which I would think would load it into my current scope according to dot sourcing link you sent.Why this is not the default behavior when leaking an exception and aborting I have no clue
enforcing things are arrays
yes you can wrap stuff in arrays, but that is making the callsite look ugly for a function definition problem. The solution "return ,$array" is just weird
Honestly I prefer the bash way of $yaml | yaml2json(.exe) | convert-fromjson. Easier to find cross platform converters which your example is not. Takes me like 5 seconds to write, however then I have to teach others to do it as well, I want it in the platform. Also why they are at it, add toml support as well.for documentation
# .SYNOPSIS
# Why do I need to type .SYNOPSIS above here, and yes that extra line is too many
function foo(
# but here its just obviously a comment for a parameter
[string] $param=""
) {
$param
}
Also didn't mention this before I wish there was a version of powershell that was static checked like typescript for javascript.I always prefer native support, but that's just me. I recently even wrote a converter for DNS bind zone files because they're such a pain to deal with as "text" files.
> Why do I need to type .SYNOPSIS above here, and yes that extra line is too many
Because there are other sections as well.
Consider yourself lucky! If you're writing binary modules in C#, the automatic help generation is missing. Instead, you have to use a hideous legacy XML-based help system nobody asked for. There are thankfully generators available now that plug into the Visual Studio build system, but in the past you literally had to author these by hand.
> I wish there was a version of powershell that was static checked like typescript for javascript.
Don't we all?
Set-StrictMode adds some static checks (not enough IMHO), and there are also linters available. If using VS Code, you get a bunch by default.
Fundamentally, once I start getting too frustrated by the weak typing, I realise that I'm writing software, not scripts. I simply crack open Visual Studio and start writing C#...
> Why this is not the default behavior
PowerShell conceptually is nearly perfect at a high level. It was originally called the "monad shell", and that design pedigree still shines through.
Unfortunately the implementation has many gaps that are as yet unresolved.
I was hoping PowerShell Core would fix everything, but it only fixed a few things (parallel foreach finally!) while leaving simple things like break-on-exception on the table.
Nonetheless, having worked with both Bash and PowerShell, I hugely prefer the latter because of that purity of vision.
If it's for a day to day usage as a shell, bash / fish / zsh... are more concise and faster.
The example given on the article :
# Get all file modified in the last 3 days
Get-ChildItem -Path path -Recurse | Where-Object {
$_.LastWriteTime -gt (Get-Date).AddDays(-3)
}Is just:
find path -mtime 3
in bash ...
The object thing is nice, but using strings as output is universal.