Re: [1] + suspended (tty output) zsh -fc 'echo bug'

[P.Stephenson@xxxxxxxxxxxxx]

hzoli@xxxxxxxxxx wrote:
> On some machines, e.g. on Solaris 2.4 or on AIX the following happens:
> 
> % zsh -fc 'echo hehe' &            
> [1] 6100
> % <RETURN>
> [1]  + suspended (tty output)  zsh -fc 'echo hehe'
> % 

It's happening on the SGI here, as well.

The problem beforehand was certainly the termcap library --- Sven
produced a patch for that and I made a more primitive one --- but this
seems to be coming from the terminal set up in init_io(), so more work
is needed.

This solution delays doing things like setting up the terminal and the
termcap entry when non-interactive until called for.  This happens in
two places (1) in the echotc builtin, which needs a proper termcap
entry, (2) in zleread() which needs everything (and before there
weren't any sanity checks, either).  I've made two functions
init_shout() and init_term() (in init.c, surprisingly enough) to take
care of the initialisation and called them where it seems appropriate.

This seems to work.  I've tried (1) the example above and (2) zsh -fc
'vared DISPLAY' and (3) zsh -fc 'echotc am' and everything looks OK.
There are probably some faintly pathological examples I haven't
handled which we shall no doubt find out about.

The other point is that I've made zleread() return NULL if it couldn't
get anything by the usual route.  What we really need is a general
input routine which will use zleread() if possible and read() if not.
This would be useful for the read builtin as well as (perhaps) vared.
In fact, most of the code to do this is already there in inputline(),
except that's currently hard-wired to the shell input.  It wouldn't be
hard to fix all this, except I haven't the stamina at the moment.
Anyone else is welcome to have a go.  Just (1) rewrite inputline() to
return the line, adding the test I just put in zleread() and thinking
about what to do with prompts and when isset(ZLE) needs checking (2)
rewrite ingetc() to use the new inputline(), moving the inputsetline()
call here (3) rewrite anything which needs to read a complete input
line to call the new input line (4) all the bits I've forgotten ---
and Bob's your uncle, 'read' will now use zle.

*** Src/builtin.c.term	Tue Oct 10 01:25:52 1995
--- Src/builtin.c	Wed Oct 18 10:06:14 1995
***************
*** 4185,4191 ****
      int num, argct;
  
      s = *argv++;
!     if (!termok)
  	return 1;
      /* if the specified termcap has a numeric value, display it */
      if ((num = tgetnum(s)) != -1) {
--- 4185,4191 ----
      int num, argct;
  
      s = *argv++;
!     if (!termok && (isset(INTERACTIVE) || !init_term()))
  	return 1;
      /* if the specified termcap has a numeric value, display it */
      if ((num = tgetnum(s)) != -1) {
*** Src/init.c.term	Tue Oct 10 01:26:10 1995
--- Src/init.c	Wed Oct 18 10:09:42 1995
***************
*** 314,319 ****
--- 314,339 ----
  
  /**/
  void
+ init_shout(void)
+ {
+ #if defined(JOB_CONTROL) && defined(TIOCSETD) && defined(NTTYDISC)
+   int ldisc = NTTYDISC;
+ 
+   ioctl(SHTTY, TIOCSETD, (char *)&ldisc);
+ #endif
+ 
+   /* Associate terminal file descriptor with a FILE pointer */
+   shout = fdopen(SHTTY, "w");
+   
+   gettyinfo(&shttyinfo);	/* get tty state */
+ #if defined(__sgi)
+   if (shttyinfo.tio.c_cc[VSWTCH] <= 0)	/* hack for irises */
+       shttyinfo.tio.c_cc[VSWTCH] = CSWTCH;
+ #endif
+ }
+ 
+ /**/
+ void
  init_io(void)
  {
      long ttpgrp;
***************
*** 348,372 ****
      if (SHTTY == -1)
  	SHTTY = movefd(open("/dev/tty", O_RDWR));
  
!     if (SHTTY != -1) {
! #if defined(JOB_CONTROL) && defined(TIOCSETD) && defined(NTTYDISC)
! 	int ldisc = NTTYDISC;
! 
! 	ioctl(SHTTY, TIOCSETD, (char *)&ldisc);
! #endif
! 
! 	/* Associate terminal file descriptor with a FILE pointer */
! 	shout = fdopen(SHTTY, "w");
  
          /* We will only use zle if shell is interactive, *
           * SHTTY != -1, and shout != 0                   */
  	opts[USEZLE] = (interact && shout) ? OPT_SET : OPT_UNSET;
- 
- 	gettyinfo(&shttyinfo);	/* get tty state */
- #if defined(__sgi)
- 	if (shttyinfo.tio.c_cc[VSWTCH] <= 0)	/* hack for irises */
- 	    shttyinfo.tio.c_cc[VSWTCH] = CSWTCH;
- #endif
      } else {
  	opts[USEZLE] = OPT_UNSET;
      }
--- 368,379 ----
      if (SHTTY == -1)
  	SHTTY = movefd(open("/dev/tty", O_RDWR));
  
!     if (SHTTY != -1 && isset(INTERACTIVE)) {
! 	init_shout();
  
          /* We will only use zle if shell is interactive, *
           * SHTTY != -1, and shout != 0                   */
  	opts[USEZLE] = (interact && shout) ? OPT_SET : OPT_UNSET;
      } else {
  	opts[USEZLE] = OPT_UNSET;
      }
***************
*** 393,398 ****
--- 400,467 ----
  #else
      opts[MONITOR] = OPT_UNSET;
  #endif
+ }
+ 
+ /* Initialise termcap. */
+ extern hasam;
+ 
+ /**/
+ int
+ init_term(void)
+ {
+     if (!*term)
+ 	return termok = 0;
+ 
+     if (tgetent(termbuf, term) != 1) {
+ 	if (isset(INTERACTIVE))
+ 	    zerr("can't find termcap info for %s", term, 0);
+ 	errflag = 0;
+ 	return termok = 0;
+     } else {
+ 	char tbuf[1024], *pp;
+ 	int t0;
+ 
+ 	termok = 1;
+ 	for (t0 = 0; t0 != TC_COUNT; t0++) {
+ 	    pp = tbuf;
+ 	    zsfree(tcstr[t0]);
+ 	/* AIX tgetstr() ignores second argument */
+ 	    if (!(pp = tgetstr(tccapnams[t0], &pp)))
+ 		tcstr[t0] = NULL, tclen[t0] = 0;
+ 	    else {
+ 		tcstr[t0] = (char *) zalloc(tclen[t0] = strlen(pp) + 1);
+ 		memcpy(tcstr[t0], pp, tclen[t0]);
+ 	    }
+ 	}
+ 
+     /* if there's no termcap entry for cursor up, use single line mode. */
+ 
+ 	if (!tccan(TCUP)) {
+ 		tcstr[TCUP] = NULL;
+ 		opts[SINGLELINEZLE] = OPT_SET;
+ 	}
+ 	hasam = tgetflag("am");
+     /* if there's no termcap entry for cursor left, use \b. */
+ 
+ 	if (!tccan(TCLEFT)) {
+ 	    tcstr[TCLEFT] = ztrdup("\b");
+ 	    tclen[TCLEFT] = 1;
+ 	}
+     /* if there's no termcap entry for clear, use ^L. */
+ 
+ 	if (!tccan(TCCLEARSCREEN)) {
+ 	    tcstr[TCCLEARSCREEN] = ztrdup("\14");
+ 	    tclen[TCCLEARSCREEN] = 1;
+ 	}
+     /* if the termcap entry for down is \n, don't use it. */
+ 
+ 	if (tccan(TCDOWN) && tcstr[TCDOWN][0] == '\n') {
+ 	    tclen[TCDOWN] = 0;
+ 	    zsfree(tcstr[TCDOWN]);
+ 	    tcstr[TCDOWN] = NULL;
+ 	}
+     }
+     return termok;
  }
  
  /* Initialize lots of global variables and hash tables */
*** Src/params.c.term	Tue Oct 10 01:26:24 1995
--- Src/params.c	Wed Oct 18 10:09:45 1995
***************
*** 1700,1707 ****
      return term;
  }
  
- extern hasam;
- 
  /* Function to set value of special parameter `TERM' */
  
  /**/
--- 1700,1705 ----
***************
*** 1710,1765 ****
  {
      zsfree(term);
      term = x ? x : ztrdup("");
!     if (!*term) {
! 	termok = 0;
!     } else if (tgetent(termbuf, term) != 1) {
! 	zerr("can't find termcap info for %s", term, 0);
! 	errflag = 0;
  	termok = 0;
!     } else {
! 	char tbuf[1024], *pp;
! 	int t0;
! 
! 	termok = 1;
! 	for (t0 = 0; t0 != TC_COUNT; t0++) {
! 	    pp = tbuf;
! 	    zsfree(tcstr[t0]);
! 	/* AIX tgetstr() ignores second argument */
! 	    if (!(pp = tgetstr(tccapnams[t0], &pp)))
! 		tcstr[t0] = NULL, tclen[t0] = 0;
! 	    else {
! 		tcstr[t0] = (char *) zalloc(tclen[t0] = strlen(pp) + 1);
! 		memcpy(tcstr[t0], pp, tclen[t0]);
! 	    }
! 	}
! 
!     /* if there's no termcap entry for cursor up, use single line mode. */
! 
! 	if (!tccan(TCUP)) {
! 		tcstr[TCUP] = NULL;
! 		opts[SINGLELINEZLE] = OPT_SET;
! 	}
! 	hasam = tgetflag("am");
!     /* if there's no termcap entry for cursor left, use \b. */
! 
! 	if (!tccan(TCLEFT)) {
! 	    tcstr[TCLEFT] = ztrdup("\b");
! 	    tclen[TCLEFT] = 1;
! 	}
!     /* if there's no termcap entry for clear, use ^L. */
! 
! 	if (!tccan(TCCLEARSCREEN)) {
! 	    tcstr[TCCLEARSCREEN] = ztrdup("\14");
! 	    tclen[TCCLEARSCREEN] = 1;
! 	}
!     /* if the termcap entry for down is \n, don't use it. */
! 
! 	if (tccan(TCDOWN) && tcstr[TCDOWN][0] == '\n') {
! 	    tclen[TCDOWN] = 0;
! 	    zsfree(tcstr[TCDOWN]);
! 	    tcstr[TCDOWN] = NULL;
! 	}
!     }
  }
  
  /* We could probably replace the replenv with the actual code to *
--- 1708,1718 ----
  {
      zsfree(term);
      term = x ? x : ztrdup("");
!     if (!*term || !isset(INTERACTIVE)) {
! 	/* If non-interactive, delay setting up term till we need it. */
  	termok = 0;
!     } else 
! 	init_term();
  }
  
  /* We could probably replace the replenv with the actual code to *
*** Src/zle_main.c.term	Tue Oct 17 09:44:34 1995
--- Src/zle_main.c	Wed Oct 18 10:26:29 1995
***************
*** 354,359 ****
--- 354,372 ----
      tv.tv_sec = 0;
  #endif
  
+     if (!shout) {
+ 	if (SHTTY != -1)
+ 	    init_shout();
+ 
+ 	if (!shout)
+ 	    return NULL;
+ 	/* We could be smarter and default to a system read. */
+ 
+ 	/* If we just got a new shout, make sure the terminal is set up. */
+ 	if (!termok)
+ 	    init_term();
+     }
+ 
      fflush(shout);
      fflush(stderr);
      intr();



-- 
Peter Stephenson <pws@xxxxxx>       Tel: +49 33762 77366
WWW:  http://www.ifh.de/~pws/       Fax: +49 33762 77330
Deutches Electronen-Synchrotron --- Institut fuer Hochenergiephysik Zeuthen
DESY-IfH, 15735 Zeuthen, Germany.