exclude users in watch variable?

exclude users in watch variable?

[Andy Spiegl]

"watch=( notme )" excludes myself but is there a way to exclude other usernames?

I was trying "watch=( notme ^user1 ^user2 )" but I am expecting too much, right?

Thanks!
 Andy.


-- 
 Some people will never learn anything because they understand everything too soon.
   (Alexander Pope)

Re: exclude users in watch variable?

[Andy Spiegl]

I suppose no answer by noone means that it's impossible, right?
Thanks,
 Andy.

On 2015-02-04, 18:46, Andy Spiegl wrote:
> "watch=( notme )" excludes myself but is there a way to exclude other usernames?
> 
> I was trying "watch=( notme ^user1 ^user2 )" but I am expecting too much, right?

-- 
 me@condor:~> find . -name home
 There's no place like home.

Re: exclude users in watch variable?

[Daniel Shahaf]

$watch does not support patterns.  For an alternative I'd suggest
writing a custom precmd.  Maybe someone else has a better idea.

(Incidentally, if $watch did support patterns, you'd have needed
to (a) quote the ^ so it isn't interpreted as filename generation,
(b) consolidate the two negative patterns as '^(user1|user2)' because
otherwise between them they'd match everything.

Cheers,

Daniel

Andy Spiegl wrote on Tue, Feb 10, 2015 at 20:28:57 +0100:
> I suppose no answer by noone means that it's impossible, right?
> Thanks,
>  Andy.
> 
> On 2015-02-04, 18:46, Andy Spiegl wrote:
> > "watch=( notme )" excludes myself but is there a way to exclude other usernames?
> > 
> > I was trying "watch=( notme ^user1 ^user2 )" but I am expecting too much, right?
> 
> -- 
>  me@condor:~> find . -name home
>  There's no place like home.

Re: exclude users in watch variable?

[Andy Spiegl]

> For an alternative I'd suggest writing a custom precmd.
Thanks for the suggestion.  I started to think about how to implement
this but came to the conclusion that my zsh knowledge is not good
enough for this. :-(  I could write a perl script but in precmd ... No!

Could one of you zsh cracks give me a good start, please?

Thanks!
 Andy.

-- 
 The opossum is a very sophisticated animal.  It doesn't even get up
 until 5 or 6 pm.

Re: exclude users in watch variable?

[Daniel Shahaf]

Andy Spiegl wrote on Wed, Feb 11, 2015 at 12:46:55 +0100:
> > For an alternative I'd suggest writing a custom precmd.
> Thanks for the suggestion.  I started to think about how to implement
> this but came to the conclusion that my zsh knowledge is not good
> enough for this. :-(  I could write a perl script but in precmd ... No!
> 
> Could one of you zsh cracks give me a good start, please?
> 

Like this? ---

    autoload -Uz add-zsh-hook
    old=
    precmd_who() {
      local new="$(who)"$'\n' # add newline to reduce spurious diffs
      if [[ -n $old ]] ; then diff =(<<<$old) =(<<<$new) ; fi
      old=$new
    }
    add-zsh-hook precmd precmd_who

If 'who' doesn't run quickly in your environment you'll notice delays
before shell prompts are drawn.  The variable 'old' is in the global
namespace, you should probably name it something more unique to avoid
name collisions.

Daniel

Re: exclude users in watch variable?

[Bart Schaefer]

On Feb 11,  4:56pm, Daniel Shahaf wrote:
}
}     autoload -Uz add-zsh-hook
}     old=
}     precmd_who() {
}       local new="$(who)"$'\n' # add newline to reduce spurious diffs
}       if [[ -n $old ]] ; then diff =(<<<$old) =(<<<$new) ; fi
}       old=$new
}     }
}     add-zsh-hook precmd precmd_who
} 
} If 'who' doesn't run quickly in your environment you'll notice delays

This seems like an ideal application for the delayed-update trick.

  typeset -gH update_prompt_fd old_who
  typeset -g normal_prompt='%m $ '

  # watch_who expects a single argument that looks like "$(who)" and
  # compares it to the argument passed to the previous watch_who call
  watch_who() {
    local new="$1"$'\n'
    if [[ -n $old_who ]]
    then
      local who_prompt="$(diff =(<<<$old_who) =(<<<$new))"
      if [[ -n $who_prompt ]]
      then PROMPT="$who_prompt"$'\n'"$normal_prompt"
      fi
    fi
    old_who="$new"
  }

  # update_who is a ZLE I/O handler, which reads output from a background
  # process (expected to be "who"), passes it through watch_who, and then
  # deletes the handler instance and updates the prompt
  update_who () {
    watch_who "$(read -d '' -rE -u$1)"
    update_prompt_fd=0
    zle -F $1
    exec {1}>&-
    zle reset-prompt
  }
  zle -N update_who  

  # precmd_who sets up the update_who handler if it is available, and
  # otherwise runs watch_who directly to put the diffs into the prompt.
  # If your "who" is fast, simply skip the "zle -N" above.
  precmd_who() {
    PROMPT="$normal_prompt"
    if zle -l update_who
    then
      (( update_prompt_fd )) && zle -F $update_prompt_fd >/dev/null
      exec {update_prompt_fd}<<( who )
      zle -F -w $update_prompt_fd update_who
    else
      watch_who "$(who)"
    fi
  }

  autoload -Uz add-zsh-hook
  add-zsh-hook precmd precmd_who

Re: exclude users in watch variable?

[Peter Stephenson]

On Wed, 4 Feb 2015 18:46:06 +0100
Andy Spiegl <zsh.Andy@spiegl.de> wrote:
> "watch=( notme )" excludes myself but is there a way to exclude other
> usernames?
> 
> I was trying "watch=( notme ^user1 ^user2 )" but I am expecting too
> much, right? 

Patterns are easy to add, we might as well do it.  I can't see how this
could be problematic since user names tty names and host names can't
contain pattern characters.

Note you'll need to do it the way suggested in the example: the list
you've got won't work because you're looking for an "or" of 'anyone apart
from me', 'anyone apart from user1', 'anyone apart from user2'.  In
fact, you can basically only use one negative in the list since "or"ing
negatives isn't useful.  I'm not proposing to change this since there
isn't a convenient alternative behaviour.

pws

diff --git a/Doc/Zsh/params.yo b/Doc/Zsh/params.yo
index ee7c054..273be21 100644
--- a/Doc/Zsh/params.yo
+++ b/Doc/Zsh/params.yo
@@ -1472,15 +1472,27 @@ vindex(watch)
 vindex(WATCH)
 item(tt(watch) <S> <Z> (tt(WATCH) <S>))(
 An array (colon-separated list) of login/logout events to report.
+
 If it contains the single word `tt(all)', then all login/logout events
 are reported.  If it contains the single word `tt(notme)', then all
 events are reported as with `tt(all)' except tt($USERNAME).
+
 An entry in this list may consist of a username,
 an `tt(@)' followed by a remote hostname,
-and a `tt(%)' followed by a line (tty).
+and a `tt(%)' followed by a line (tty).  Any of these may
+be a pattern (be sure to quote this during the assignment to
+tt(watch) so that it does not immediately perform file generation);
+the setting of the tt(EXTENDED_GLOB) option is respected.
 Any or all of these components may be present in an entry;
 if a login/logout event matches all of them,
 it is reported.
+
+For example, with the tt(EXTENDED_GLOB) option set, the following:
+
+example(watch=('^(pws|barts)'))
+
+causes reports for activity assoicated with any user other than tt(pws)
+or tt(barts).
 )
 vindex(WATCHFMT)
 item(tt(WATCHFMT))(
diff --git a/Src/watch.c b/Src/watch.c
index 8dea0b4..fe409f9 100644
--- a/Src/watch.c
+++ b/Src/watch.c
@@ -372,6 +372,27 @@ watchlog2(int inout, WATCH_STRUCT_UTMP *u, char *fmt, int prnt, int fini)
     return fmt;
 }
 
+/* See if the watch entry matches */
+
+static int
+watchlog_match(char *teststr, char *actual, int len)
+{
+    int ret = 0;
+    Patprog pprog;
+    char *str = dupstring(teststr);
+
+    tokenize(str);
+
+    if ((pprog = patcompile(str, PAT_STATIC, 0))) {
+	queue_signals();
+	if (pattry(pprog, actual))
+	    ret = 1;
+	unqueue_signals();
+    } else if (!strncmp(actual, teststr, len))
+	ret = 1;
+    return ret;
+}
+
 /* check the List for login/logouts */
 
 /**/
@@ -400,7 +421,7 @@ watchlog(int inout, WATCH_STRUCT_UTMP *u, char **w, char *fmt)
 	    for (vv = v; *vv && *vv != '@' && *vv != '%'; vv++);
 	    sav = *vv;
 	    *vv = '\0';
-	    if (strncmp(u->ut_name, v, sizeof(u->ut_name)))
+	    if (!watchlog_match(v, u->ut_name, sizeof(u->ut_name)))
 		bad = 1;
 	    *vv = sav;
 	    v = vv;
@@ -410,7 +431,7 @@ watchlog(int inout, WATCH_STRUCT_UTMP *u, char **w, char *fmt)
 		for (vv = ++v; *vv && *vv != '@'; vv++);
 		sav = *vv;
 		*vv = '\0';
-		if (strncmp(u->ut_line, v, sizeof(u->ut_line)))
+		if (!watchlog_match(v, u->ut_line, sizeof(u->ut_line)))
 		    bad = 1;
 		*vv = sav;
 		v = vv;
@@ -420,7 +441,7 @@ watchlog(int inout, WATCH_STRUCT_UTMP *u, char **w, char *fmt)
 		for (vv = ++v; *vv && *vv != '%'; vv++);
 		sav = *vv;
 		*vv = '\0';
-		if (strncmp(u->ut_host, v, strlen(v)))
+		if (!watchlog_match(v, u->ut_host, strlen(v)))
 		    bad = 1;
 		*vv = sav;
 		v = vv;

Re: exclude users in watch variable?

[Andy Spiegl]

> Patterns are easy to add, we might as well do it.
Very cool, thanks!

> Note you'll need to do it the way suggested in the example:
Yes, sounds very logical.
When typing my example I was thinking on / proposing a much easier level. :-)

I assume this won't make it into the next Debian release, right?
I'm using zsh on too many machines to manually install this patch
without big efforts.

Thanks,
 Andy.


-- 
 All the President is, is a glorified public relations man who spends his time
 flattering, kissing and kicking people to get them to do what they are supposed
 to do anyway.  (Harry S. Truman)