> What's the point of the shell, if not to manage your databases, your REST APIs, files, and mail? Is it something you use for playing games on, or just for fun?
To call other programs to do those things. Why on earth would I want my shell to directly manage any of those things?
I think you're forgetting something: *nix tools are built by a community, PowerShell is built by a company. Much like Apple, Microsoft can insist on and guarantee that their internal API is consistent. *nix tooling cannot (nor would it ever try to) do the same.
> It means that "ps" has a built-in sort command, as do most other UNIX standard utilities, but they all do it differently.
I haven't done an exhaustive search, but I doubt that most *nix tooling has a built-in sort. Generally speaking, they're built on the assumption that you'll pipe output as necessary to other tools.
> This also means that you just "need to know" how to convince each and every command to output machine-readable formats that other tools on the pipeline can pick up safely.
No, you don't, because plaintext output is the lingua franca of *nix tooling. If you build a tool intended for public consumption and it _doesn't_ output in plaintext by default, you're doing it wrong.
Here's a one-liner with GNU awk; you can elide the first `printf` if you don't want headers. Similarly, you can change the output formatting however you want. Or, you could skip that altogether, and pipe the output to `column -t` to let it handle alignment.
netstat -nA inet | gawk -F':' 'NR > 2 { split($2, a, / /); pc[a[1]]++ } END { printf "%-5s %s\n", "PORT", "COUNT"; PROCINFO["sorted_in"]="@val_num_desc"; c=0; for(i in pc) if (c++ < 10) { printf "%-5s %-5s\n", i, pc[i] } }'
Obviously this is not as immediately straight-forward for the specific task, though if you already know awk, it kind of is:
Set the field separator to `:`
Skip the first two lines (because they're informational headers)
Split the 2nd column on space to skip the foreign IP
Store that result in variable `a`
Create and increment array `pc` keyed on the port
When done, do the following
Print a header
Sort numerically, descending
Initialize a counter at 0
For every element in the pc array, until count hits 10, print the value and key
You can also chain together various `grep`, `sort`, and `uniq` calls as a sibling comment did. And if your distro doesn't include GNU awk, then you probably _would_ have to do this.
You may look at this and scoff, but really, what is the difference? With yours, I have to learn a bunch of commands, predicates, options, and syntax. With mine, I have to... learn a bunch of commands, predicates, options, and syntax (or just awk ;-)).
> This kind of thing is a challenge with UNIX tools
It's only a challenge if you don't know how to use the tools.
> Any change to the output format of netstat breaks scripts in fun and create ways
The last release of `netstat` was in 2014. *nix tools aren't like JavaScript land; they tend to be extremely stable. Even if they _do_ get releases, if you're using a safe distro in prod (i.e. Debian, RedHat), you're not going to get a surprise update. Finally, the authors and maintainers of such tools are painfully aware that tons of scripts around the world depend on them being consistent, and as such, are highly unlikely to break that.
> Silently. In production.
If you aren't thoroughly testing and validating changes in prod, that's not the fault of the tooling.
To call other programs to do those things. Why on earth would I want my shell to directly manage any of those things?
I think you're forgetting something: *nix tools are built by a community, PowerShell is built by a company. Much like Apple, Microsoft can insist on and guarantee that their internal API is consistent. *nix tooling cannot (nor would it ever try to) do the same.
> It means that "ps" has a built-in sort command, as do most other UNIX standard utilities, but they all do it differently.
I haven't done an exhaustive search, but I doubt that most *nix tooling has a built-in sort. Generally speaking, they're built on the assumption that you'll pipe output as necessary to other tools.
> This also means that you just "need to know" how to convince each and every command to output machine-readable formats that other tools on the pipeline can pick up safely.
No, you don't, because plaintext output is the lingua franca of *nix tooling. If you build a tool intended for public consumption and it _doesn't_ output in plaintext by default, you're doing it wrong.
Here's a one-liner with GNU awk; you can elide the first `printf` if you don't want headers. Similarly, you can change the output formatting however you want. Or, you could skip that altogether, and pipe the output to `column -t` to let it handle alignment.
Example output: Obviously this is not as immediately straight-forward for the specific task, though if you already know awk, it kind of is: You can also chain together various `grep`, `sort`, and `uniq` calls as a sibling comment did. And if your distro doesn't include GNU awk, then you probably _would_ have to do this.You may look at this and scoff, but really, what is the difference? With yours, I have to learn a bunch of commands, predicates, options, and syntax. With mine, I have to... learn a bunch of commands, predicates, options, and syntax (or just awk ;-)).
> This kind of thing is a challenge with UNIX tools
It's only a challenge if you don't know how to use the tools.
> Any change to the output format of netstat breaks scripts in fun and create ways
The last release of `netstat` was in 2014. *nix tools aren't like JavaScript land; they tend to be extremely stable. Even if they _do_ get releases, if you're using a safe distro in prod (i.e. Debian, RedHat), you're not going to get a surprise update. Finally, the authors and maintainers of such tools are painfully aware that tons of scripts around the world depend on them being consistent, and as such, are highly unlikely to break that.
> Silently. In production.
If you aren't thoroughly testing and validating changes in prod, that's not the fault of the tooling.