[9fans] rc: <{command} and > mess with exit status

[9fans] rc: <{command} and > mess with exit status

[adr via 9fans]

; if(grep a <{echo a}) echo true
a
true

;  if(echo a | grep a >/tmp/1) echo true
true

But now:
; if(grep a <{echo a} >/tmp/1) echo true
;

Is this expected?

Regards,
adr.

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Re: [9fans] rc: <{command} and > mess with exit status

[Sigrid Solveig Haflínudóttir]

; if(grep a <{echo a}) echo true
a
true
; if(echo a | grep a >/tmp/1) echo true
true
; if(grep a <{echo a} >/tmp/1) echo true
true

9front.


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Re: [9fans] rc: <{command} and > mess with exit status

[adr via 9fans]

Thanks, it looks like a bug.

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[9fans] Re: rc: <{command} and > mess with exit status

[Anthony Martin]

adr via 9fans <9fans@9fans.net> once said:
> ; if(grep a <{echo a} >/tmp/1) echo true
> ;
>
> Is this expected?

This was fixed a few years ago in 9front:

http://git.9front.org/plan9front/plan9front/2839760066e578e449ebc8b3d71297b9f79a8c99/commit.html

Cheers,
  Anthony

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Re: [9fans] rc: <{command} and > mess with exit status

[ori]

Quoth adr via 9fans <9fans@9fans.net>:
> ; if(grep a <{echo a}) echo true
> a
> true
> 
> ;  if(echo a | grep a >/tmp/1) echo true
> true
> 
> But now:
> ; if(grep a <{echo a} >/tmp/1) echo true
> ;
> 
> Is this expected?

It's been fixed. Here's the patch:

<git/export 2839760066e578e449ebc8b3d71297b9f79a8c99

From 2839760066e578e449ebc8b3d71297b9f79a8c99
From: cinap_lenrek <cinap_lenrek@felloff.net>
Date: Sat, 08 Sep 2018 12:49:00 +0000
Subject: [PATCH] rc: fix Xpipefd unbalancing the redir stack


Xpipefd wants the pipe descriptor to be closed in turfredir(), so
it pushes the redirection, but this breaks Xpopredir after normal
redirection. so we shuffle the Xpipefd redir to the bottom of the
stack.
---
diff 217e8a06198cf6681fb0c38c26f34d96ae4302f6 2839760066e578e449ebc8b3d71297b9f79a8c99
--- a/sys/src/cmd/rc/exec.c     Mon Sep  3 16:37:45 2018
+++ b/sys/src/cmd/rc/exec.c     Sat Sep  8 08:49:00 2018
@@ -123,6 +123,21 @@
        runq->redir = rp;
 }
 
+void
+shuffleredir(void)
+{
+       redir **rr, *rp;
+
+       rp = runq->redir;
+       if(rp==0)
+               return;
+       runq->redir = rp->next;
+       rp->next = runq->startredir;
+       for(rr = &runq->redir; *rr != rp->next; rr = &((*rr)->next))
+               ;
+       *rr = rp;
+}
+
 var*
 newvar(char *name, var *next)
 {
--- a/sys/src/cmd/rc/fns.h      Mon Sep  3 16:37:45 2018
+++ b/sys/src/cmd/rc/fns.h      Sat Sep  8 08:49:00 2018
@@ -55,6 +55,7 @@
 word*  searchpath(char*);
 void   setstatus(char*);
 void   setvar(char*, word*);
+void   shuffleredir(void);
 void   skipnl(void);
 void   start(code*, int, var*);
 int    truestatus(void);
--- a/sys/src/cmd/rc/havefork.c Mon Sep  3 16:37:45 2018
+++ b/sys/src/cmd/rc/havefork.c Sat Sep  8 08:49:00 2018
@@ -185,7 +185,8 @@
        default:
                addwaitpid(pid);
                close(sidefd);
-               pushredir(ROPEN, mainfd, mainfd);       /* isn't this a noop? */
+               pushredir(ROPEN, mainfd, mainfd);
+               shuffleredir(); /* shuffle redir to bottom of stack for turfredir() */
                strcpy(name, Fdprefix);
                inttoascii(name+strlen(name), mainfd);
                pushword(name);
@{
        bind -ac /dist/plan9front/ /
        git/export 2839760066e578e449ebc8b3d71297b9f79a8c99
}

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Re: [9fans] rc: <{command} and > mess with exit status

[adr via 9fans]

Thanks for the patch!

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