On 4/27/23 06:34, Janis Papanagnou wrote:
> s sees what files the shell matched and provides an
> expanded matching files list (unless there's no match, in that case
> the literal 'x*' is passed).

flatbush:[ruben]:~$ cd ~/mnt/ ; ls *
AVF_INFO:
AVIN0001.BNP AVIN0001.INP AVIN0001.INT PRV00001.BIN

that lists the subdirectory

flatbush:[ruben]:~$ ps -ef | grep "$(basename "$0")"
root 339 2991 0 Apr09 tty3 00:00:00 -bash
ruben 1091 1090 0 Apr24 pts/5 00:00:00 -bash
ruben 7745 7743 0 Apr19 pts/8 00:00:00 bash
ruben 8999 8996 0 Apr17 pts/4 00:00:00 bash
ruben 9260 9258 0 Apr24 pts/1 00:00:00 bash
ruben 14427 14425 0 06:10 pts/6 00:00:00 bash
ruben 18922 14427 0 06:46 pts/6 00:00:00 grep --colour=auto bash
ruben 28570 28569 0 Apr24 pts/3 00:00:00 -bash
ruben 30315 30314 0 Apr24 pts/2 00:00:00 -bash
ruben 30844 30842 0 Apr23 pts/0 00:00:00 bash
ruben 31263 2986 0 Mar17 tty2 00:00:00 -bash

* Popping Mad <rainbow@colition.gov>:
> flatbush:[ruben]:~$ ps -ef | grep "$(basename "$0")"

Because you're obviously running that from bash?

I mean, what else would you expect there?

--
Dipl.-Inform. Felix Palmen <felix@palmen-it.de> ,.//..........
{web} http://palmen-it.de {jabber} [see email] ,//palmen-it.de
{pgp public key} http://palmen-it.de/pub.txt // """""""""""
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On 4/25/23 07:05, Felix Palmen wrote:
> * Popping Mad <rainbow@colition.gov>:
>> flatbush:[ruben]:~$ ps -ef | grep "$(basename "$0")"
>
> Because you're obviously running that from bash?
>
> I mean, what else would you expect there?
>

ps

Popping Mad <rainbow@colition.gov> writes:
> On 4/25/23 07:05, Felix Palmen wrote:
>> * Popping Mad <rainbow@colition.gov>:
>>> flatbush:[ruben]:~$ ps -ef | grep "$(basename "$0")"
>>
>> Because you're obviously running that from bash?
>>
>> I mean, what else would you expect there?
>>
>
>
> ps

"$0" is expanded by the bash process, not by the ps process.

--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for XCOM Labs
void Void(void) { Void(); } /* The recursive call of the void */

On 26.04.23 03:39, Keith Thompson wrote:
> Popping Mad <rainbow@colition.gov> writes:
>> On 4/25/23 07:05, Felix Palmen wrote:
>>> * Popping Mad <rainbow@colition.gov>:
>>>> flatbush:[ruben]:~$ ps -ef | grep "$(basename "$0")"
>>>
>>> Because you're obviously running that from bash?
>>>
>>> I mean, what else would you expect there?
>>>
>>
>>
>> ps
>
> "$0" is expanded by the bash process, not by the ps process.
>
Hint: count the double quotes until you reach the $0, or better yet ...
toggle "inside"/"outside" each time you encounter one.
NB Not that the double quotes will prevent the $0 from bein expanded
when seen!

Josef

On 26.04.2023 10:46, Josef Moellers wrote:
> On 26.04.23 03:39, Keith Thompson wrote:
>> Popping Mad <rainbow@colition.gov> writes:
>>> On 4/25/23 07:05, Felix Palmen wrote:
>>>> * Popping Mad <rainbow@colition.gov>:
>>>>> flatbush:[ruben]:~$ ps -ef | grep "$(basename "$0")"
>>>>
>>>> Because you're obviously running that from bash?
>>>> I mean, what else would you expect there?
>>>
>>> ps
>>
>> "$0" is expanded by the bash process, not by the ps process.
>>
> Hint: count the double quotes until you reach the $0, or better yet ...
> toggle "inside"/"outside" each time you encounter one.

To "toggle" is a wrong advice _here_; for nested subshells,
like "$(basename "$0")" it is _counting_.

Janis

On 26.04.23 11:16, Janis Papanagnou wrote:
> On 26.04.2023 10:46, Josef Moellers wrote:
>> On 26.04.23 03:39, Keith Thompson wrote:
>>> Popping Mad <rainbow@colition.gov> writes:
>>>> On 4/25/23 07:05, Felix Palmen wrote:
>>>>> * Popping Mad <rainbow@colition.gov>:
>>>>>> flatbush:[ruben]:~$ ps -ef | grep "$(basename "$0")"
>>>>>
>>>>> Because you're obviously running that from bash?
>>>>> I mean, what else would you expect there?
>>>>
>>>> ps
>>>
>>> "$0" is expanded by the bash process, not by the ps process.
>>>
>> Hint: count the double quotes until you reach the $0, or better yet ...
>> toggle "inside"/"outside" each time you encounter one.
>
> To "toggle" is a wrong advice _here_; for nested subshells,
> like "$(basename "$0")" it is _counting_.

I stand corrected!

Josef

On 4/26/23 05:16, Janis Papanagnou wrote:
> or nested subshells,
> like "$(basename "$0")" it is _counting_.

counting what?

On 26.04.23 13:03, Popping Mad wrote:
> On 4/26/23 05:16, Janis Papanagnou wrote:
>> or nested subshells,
>> like "$(basename "$0")" it is _counting_.
>
>
> counting what?

"count the double quotes"

Josef

On 26.04.2023 13:03, Popping Mad wrote:
> On 4/26/23 05:16, Janis Papanagnou wrote:
>> or nested subshells,
>> like "$(basename "$0")" it is _counting_.
>
>
> counting what?

Josef mentioned two cases; toggling and counting [of quotes].

Example for case 1, toggling: x="ab cd"*"de fg"
the first quote gets closed by the second one, unquoted *,
the third one gets closed by the fourth one.

Example for case 2, counting: echo "$(basename "$0")"
the $(...) subshell expansion opens its own new embedded
"quote space", so the first quote is closed by the fourth,
and the second one by the third.
"$(
"$0"
)"

Janis

Popping Mad <rainbow@colition.gov> writes:
> flatbush:[ruben]:~$ ps -ef | grep "$(basename "$0")"
> root 339 2991 0 Apr09 tty3 00:00:00 -bash
> ruben 1091 1090 0 Apr24 pts/5 00:00:00 -bash
> ruben 7745 7743 0 Apr19 pts/8 00:00:00 bash
> ruben 8999 8996 0 Apr17 pts/4 00:00:00 bash
> ruben 9260 9258 0 Apr24 pts/1 00:00:00 bash
> ruben 14427 14425 0 06:10 pts/6 00:00:00 bash
> ruben 18922 14427 0 06:46 pts/6 00:00:00 grep --colour=auto bash
> ruben 28570 28569 0 Apr24 pts/3 00:00:00 -bash
> ruben 30315 30314 0 Apr24 pts/2 00:00:00 -bash
> ruben 30844 30842 0 Apr23 pts/0 00:00:00 bash
> ruben 31263 2986 0 Mar17 tty2 00:00:00 -bash

I don't think you ever said what you're trying to accomplish. If your
question was based on idle curiousity, that's fine, but if you're trying
to do something specific (apparently filtering the output of `ps -ef`),
you need to tell us what your goal is.

--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for XCOM Labs
void Void(void) { Void(); } /* The recursive call of the void */

In article <87cz3qeib2.fsf@nosuchdomain.example.com>,
Keith Thompson <Keith.S.Thompson+u@gmail.com> wrote:
>Popping Mad <rainbow@colition.gov> writes:
>> flatbush:[ruben]:~$ ps -ef | grep "$(basename "$0")"
>> root 339 2991 0 Apr09 tty3 00:00:00 -bash
>> ruben 1091 1090 0 Apr24 pts/5 00:00:00 -bash
>> ruben 7745 7743 0 Apr19 pts/8 00:00:00 bash
>> ruben 8999 8996 0 Apr17 pts/4 00:00:00 bash
>> ruben 9260 9258 0 Apr24 pts/1 00:00:00 bash
>> ruben 14427 14425 0 06:10 pts/6 00:00:00 bash
>> ruben 18922 14427 0 06:46 pts/6 00:00:00 grep --colour=auto bash
>> ruben 28570 28569 0 Apr24 pts/3 00:00:00 -bash
>> ruben 30315 30314 0 Apr24 pts/2 00:00:00 -bash
>> ruben 30844 30842 0 Apr23 pts/0 00:00:00 bash
>> ruben 31263 2986 0 Mar17 tty2 00:00:00 -bash
>
>I don't think you ever said what you're trying to accomplish.

That is standard for these kinds of questions. To tell, would give the
game away.

>If your question was based on idle curiosity, that's fine, but if you're
>trying to do something specific (apparently filtering the output of `ps
>-ef`), you need to tell us what your goal is.

Again, the whole point of threads like this is for us to guess at what OP's
real problem is (if indeed, there is any and it is not just trolling). And
to fight amongst ourselves over whose interpretation is correct. As we are
now doing.

--
If you ask a Trumper who is to blame for the debacle of Jan 6, they will almost certainly say
something about Antifa/BLM/something/whatever. This shows just how screwed up they are; they can't
even get their narrative straight. What they *should* say is "Eugene Goodman". If not for him, the plot
would probably have succeeded, so he (Eugene) is clearly to blame for the failure.

On 2023-04-26, Popping Mad <rainbow@colition.gov> wrote:
> On 4/25/23 07:05, Felix Palmen wrote:
>> * Popping Mad <rainbow@colition.gov>:
>>> flatbush:[ruben]:~$ ps -ef | grep "$(basename "$0")"
>>
>> Because you're obviously running that from bash?
>>
>> I mean, what else would you expect there?
>>
>
>
> ps

Let's assume we have no idea that $0 is expanded by the shell before
it executes the command.

Why would we expect "ps", rather than "grep"?

--
TXR Programming Language: http://nongnu.org/txr
Cygnal: Cygwin Native Application Library: http://kylheku.com/cygnal
Mastodon: @Kazinator@mstdn.ca

* Kaz Kylheku <864-117-4973@kylheku.com>:
> On 2023-04-26, Popping Mad <rainbow@colition.gov> wrote:
>> On 4/25/23 07:05, Felix Palmen wrote:
>>> * Popping Mad <rainbow@colition.gov>:
>>>> flatbush:[ruben]:~$ ps -ef | grep "$(basename "$0")"
>>>
>>> Because you're obviously running that from bash?
>>>
>>> I mean, what else would you expect there?
>>
>> ps

I see, this is an attempt to "reuse" a commandline, right? I mean,
"grep ps" would be horrible "hardcoding" ^^

> Let's assume we have no idea that $0 is expanded by the shell before
> it executes the command.
>
> Why would we expect "ps", rather than "grep"?

Then why "grep", rather than "basename"?

And then, we should finally see how $0 would be utterly pointless if
*not* expanded by the shell ;)

--
Dipl.-Inform. Felix Palmen <felix@palmen-it.de> ,.//..........
{web} http://palmen-it.de {jabber} [see email] ,//palmen-it.de
{pgp public key} http://palmen-it.de/pub.txt // """""""""""
{pgp fingerprint} 6936 13D5 5BBF 4837 B212 3ACC 54AD E006 9879 F231

On 4/26/23 12:44, Kaz Kylheku wrote:
> Why would we expect "ps", rather than "grep"?

actually, I would think it would be basename, not ps.

On 4/26/23 13:14, Felix Palmen wrote:
> And then, we should finally see how $0 would be utterly pointless if
> *not* expanded by the shell ;)

If it is always exanded by the shell prior to execution, it is then
always the name of the shell being invoked.. Does tht also not seem to
be pointless.

On 4/26/23 12:09, Keith Thompson wrote:
> I don't think you ever said what you're trying to accomplish. If your
> question was based on idle curiousity, that's fine, but if you're trying
> to do something specific (apparently filtering the output of `ps -ef`),
> you need to tell us what your goal is.
http://mywiki.wooledge.org/ProcessManagement#How_do_I_make_sure_only_one_copy_of_my_script_can_run_at_a_time.3F

On 4/26/23 12:38, Kenny McCormack wrote:
> Again, the whole point of threads like this is for us to guess at what OP's
> real problem is

No - but the cynicism is appreciated. It is ACTUALLY an attempt to
understand how it works with no specific task in mind.

On 4/26/23 12:09, Keith Thompson wrote:
> I don't think you ever said what you're trying to accomplish. If your
> question was based on idle curiousity, that's fine, but if you're trying
> to do something specific (apparently filtering the output of `ps -ef`),
> you need to tell us what your goal is.

It was an example I read somewhere that I tried to execute in order to
understand it...

On 4/26/23 12:09, Keith Thompson wrote:
> I don't think you ever said what you're trying to accomplish. If your
> question was based on idle curiousity, that's fine, but if you're trying
> to do something specific (apparently filtering the output of `ps -ef`),
> you need to tell us what your goal is.

It was an example I read somewhere that I tried to execute in order to
understand it...

On Thu, 27 Apr 2023 00:55:53 -0400
Popping Mad <rainbow@colition.gov> wrote:
> On 4/26/23 13:14, Felix Palmen wrote:
> > And then, we should finally see how $0 would be utterly pointless if
> > *not* expanded by the shell ;)
>
> If it is always exanded by the shell prior to execution, it is then
> always the name of the shell being invoked.. Does tht also not seem to
> be pointless.

It isn't always the name of the shell. Say I have a file named
my-beautiful-shell-script which contains only 1 line :
echo $0

..If I do bash my-beautiful-shell-script I see
my-beautiful-shell-script

If I make my-beautiful-shell-script have 2 lines :
#!/bin/bash
echo $0

and make it executable and execute it with ./my-beautiful-shell-script ,
I see
../my-beautiful-shell-script

[ Post concerning expansion of basename "$0" ]

On 27.04.2023 06:52, Popping Mad wrote:
> On 4/26/23 12:44, Kaz Kylheku wrote:
>> Why would we expect "ps", rather than "grep"?
>
> actually, I would think it would be basename, not ps.

Ah, I see, thanks for clarifying. - This assumes that $0 is expanded
by the command using it as argument, i.e. the MD DOS approach; every
(raw!) text data passed with the call is expanded by the respective
command, so [in DOS] every command has to implement or call the same
argument parsing routines. - Unix shells are different; the shell is
doing expansions (typically expansions can be spotted by a '$', like
$var, ${var}, $(cmd), $((expr)), etc., or by the file globbing, *, ?,
[...], etc.) and the _expanded_ text is passed to the program. So in
basename "$0" ; ls x* ; # etc. (for example)
The command basename sees what is expanded by the shell (from where
you called it), ls sees what files the shell matched and provides an
expanded matching files list (unless there's no match, in that case
the literal 'x*' is passed). So an argument expansion with a $ will
not be seen literally by the program unless it is single quoted or
the $ escaped ('$0' or \$0). (The double quoting has also yet more
semantics (as opposed to no quoting), BTW; also important to know,
see "field-splitting" in the docs.)

This is how Unix shells work. It may make sense to take an hour or
two to read about "command processing" in shells; the command line
parsing process has a lot of steps that you shall be aware of if you
intend to program in shell.

Janis

On 4/27/23 04:33, Spiros Bousbouras wrote:
> If I make my-beautiful-shell-script have 2 lines :
> #!/bin/bash
> echo $0
>
> and make it executable and execute it with ./my-beautiful-shell-script ,
> I see
> ./my-beautiful-shell-script

Thank you.

But I fail to see the mechanism that would make that happen like that.
Why does it make a different from the command line than from a script?

* Popping Mad <rainbow@colition.gov>:
> But I fail to see the mechanism that would make that happen like that.
> Why does it make a different from the command line than from a script?

For a script, the script is (logically) the executable, the shell just
acts as an interpreter and will set $0 accordingly.

When you just type commands in an interactive shell, there's no
executable. Well, besides the shell itself of course.

--
Dipl.-Inform. Felix Palmen <felix@palmen-it.de> ,.//..........
{web} http://palmen-it.de {jabber} [see email] ,//palmen-it.de
{pgp public key} http://palmen-it.de/pub.txt // """""""""""
{pgp fingerprint} 6936 13D5 5BBF 4837 B212 3ACC 54AD E006 9879 F231