From: Eric Freese <ericdfreese@gmail.com>
To: Peter Stephenson <p.stephenson@samsung.com>
Cc: Zsh Users <zsh-users@zsh.org>
Subject: Re: Anyone familiar with auto-fu.zsh project?
Date: Tue, 12 Jun 2018 22:09:59 -0600 [thread overview]
Message-ID: <CAAikoAJYE=vyLUpwZcG4j85ENxqVVfRqDSFms1dOFUTzx52Pig@mail.gmail.com> (raw)
In-Reply-To: <20180612113257eucas1p2342f735bcea27bb1009aee1b23c682f0~3ZmPbMrh61839118391eucas1p2G@eucas1p2.samsung.com>
[-- Attachment #1: Type: text/plain, Size: 5490 bytes --]
> We could add it to the $sysparams hash provided by the zsh/system
module?
It just occurred to me that, with zsh/system, I can have the child process
send its pid as the first line of output.
Something like:
```
% zmodload zsh/system
% exec {FOO}< <(echo $sysparams[pid]; sleep 100; echo foo bar)
% read childpid <&$FOO # Get the pid, stored in $childpid
% cat <&$FOO # Handle the rest of the output
```
So it may not actually be necessary to add procsubstpid.
In fact, the approach above may be preferred if you need to get pids for
multiple process substitutions in one command (which I think is possible?).
Next question:
Is it possible to get the current subshell's pid without having to load the
zsh/system module ($sysparams param)? Bash seems to have the $BASHPID
variable. Is there anything like that in zsh core?
Or, alternatively, is it reasonable to assume that everyone will be able to
load the zsh/system module? Background here is that I had a user send a
pull request to zsh-autosuggestions requesting we don't depend on zsh/zpty
module since some people may not have it installed, so I'm trying to
minimize dependencies on non-core modules.
Eric Freese
303 875 2359
On Tue, Jun 12, 2018 at 5:32 AM, Peter Stephenson <p.stephenson@samsung.com>
wrote:
> On Mon, 11 Jun 2018 19:55:32 -0600
> Eric Freese <ericdfreese@gmail.com> wrote:
> > Do you know if there is any way to get the PID of the process spawned
> > for process substitution? It looks like `$!` doesn't hold it as it
> > does in bash.
>
> Hmm, this is obviously useful but I'd be loath simply to make $! do this
> as the fact there's an asynchronous process involved is a bit hidden and
> the mechanism is rather different from creating a background job, so
> that could be confusing.
>
> We could add it to the $sysparams hash provided by the zsh/system
> module? This already contains some PID information. (It's
> not strictly a system parameter but I don't think anyone's
> going to hold a gun to my head and tell me this hash can only
> return the result of immediate system calls.)
>
> pws
>
> diff --git a/Doc/Zsh/mod_system.yo b/Doc/Zsh/mod_system.yo
> index 7f2009b..a27bab4 100644
> --- a/Doc/Zsh/mod_system.yo
> +++ b/Doc/Zsh/mod_system.yo
> @@ -255,6 +255,11 @@ Returns the process ID of the parent of the current
> process, even in
> subshells. Compare tt($PPID), which returns the process ID of the parent
> of the main shell process.
> )
> +item(tt(procsubstpid))(
> +Returns the process ID of the last process started for process
> +substitution, i.e. the tt(<LPAR())var(...)tt(RPAR()) and
> +tt(>LPAR())var(...)tt(RPAR()) expansions.
> +)
> enditem()
> )
> enditem()
> diff --git a/Src/Modules/system.c b/Src/Modules/system.c
> index 9fd4d25..7a4f4ee 100644
> --- a/Src/Modules/system.c
> +++ b/Src/Modules/system.c
> @@ -772,6 +772,8 @@ fillpmsysparams(Param pm, const char *name)
> num = (int)getpid();
> } else if (!strcmp(name, "ppid")) {
> num = (int)getppid();
> + } else if (!strcmp(name, "procsubstpid")) {
> + num = (int)procsubstpid;
> } else {
> pm->u.str = dupstring("");
> pm->node.flags |= PM_UNSET;
> @@ -805,6 +807,8 @@ scanpmsysparams(UNUSED(HashTable ht), ScanFunc func,
> int flags)
> func(&spm.node, flags);
> fillpmsysparams(&spm, "ppid");
> func(&spm.node, flags);
> + fillpmsysparams(&spm, "procsubstpid");
> + func(&spm.node, flags);
> }
>
> static struct mathfunc mftab[] = {
> diff --git a/Src/exec.c b/Src/exec.c
> index 963b0a5..d445278 100644
> --- a/Src/exec.c
> +++ b/Src/exec.c
> @@ -174,6 +174,11 @@ mod_export int zleactive;
> /**/
> pid_t cmdoutpid;
>
> +/* pid of last process started by <(...), >(...) */
> +
> +/**/
> +mod_export pid_t procsubstpid;
> +
> /* exit status of process undergoing 'process substitution' */
>
> /**/
> @@ -4850,6 +4855,7 @@ getproc(char *cmd, char **eptr)
> return NULL;
> if (!out)
> addproc(pid, NULL, 1, &bgtime);
> + procsubstpid = pid;
> return pnam;
> }
> closem(FDT_UNUSED, 0);
> @@ -4887,6 +4893,7 @@ getproc(char *cmd, char **eptr)
> {
> addproc(pid, NULL, 1, &bgtime);
> }
> + procsubstpid = pid;
> return pnam;
> }
> entersubsh(ESUB_ASYNC|ESUB_PGRP);
> @@ -4937,6 +4944,7 @@ getpipe(char *cmd, int nullexec)
> }
> if (!nullexec)
> addproc(pid, NULL, 1, &bgtime);
> + procsubstpid = pid;
> return pipes[!out];
> }
> entersubsh(ESUB_PGRP);
> @@ -6172,6 +6180,7 @@ execsave(void)
> es->cmdoutpid = cmdoutpid;
> es->cmdoutval = cmdoutval;
> es->use_cmdoutval = use_cmdoutval;
> + es->procsubstpid = procsubstpid;
> es->trap_return = trap_return;
> es->trap_state = trap_state;
> es->trapisfunc = trapisfunc;
> @@ -6207,6 +6216,7 @@ execrestore(void)
> cmdoutpid = en->cmdoutpid;
> cmdoutval = en->cmdoutval;
> use_cmdoutval = en->use_cmdoutval;
> + procsubstpid = en->procsubstpid;
> trap_return = en->trap_return;
> trap_state = en->trap_state;
> trapisfunc = en->trapisfunc;
> diff --git a/Src/zsh.h b/Src/zsh.h
> index 8535d48..8e7f20b 100644
> --- a/Src/zsh.h
> +++ b/Src/zsh.h
> @@ -1095,6 +1095,7 @@ struct execstack {
> pid_t cmdoutpid;
> int cmdoutval;
> int use_cmdoutval;
> + pid_t procsubstpid;
> int trap_return;
> int trap_state;
> int trapisfunc;
>
>
next prev parent reply other threads:[~2018-06-13 4:10 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-06 17:42 Sebastian Gniazdowski
2018-06-06 18:35 ` Eric Freese
2018-06-09 15:30 ` Sebastian Gniazdowski
2018-06-10 0:58 ` Eric Freese
2018-06-11 5:24 ` Sebastian Gniazdowski
2018-06-11 8:25 ` Eric Freese
2018-06-11 9:46 ` Sebastian Gniazdowski
2018-06-12 1:55 ` Eric Freese
2018-06-12 10:23 ` Sebastian Gniazdowski
2018-06-12 11:32 ` Peter Stephenson
2018-06-13 4:09 ` Eric Freese [this message]
2018-06-13 7:26 ` dana
2018-06-13 7:32 ` Sebastian Gniazdowski
2018-06-13 8:28 ` Sebastian Gniazdowski
2018-06-13 9:17 ` dana
2018-06-13 10:48 ` Sebastian Gniazdowski
2018-06-13 11:43 ` dana
2018-06-14 8:55 ` Peter Stephenson
2018-06-14 9:48 ` dana
2018-06-14 10:00 ` Peter Stephenson
2018-06-13 7:27 ` Sebastian Gniazdowski
2018-06-06 23:45 ` Takeshi Banse
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