Re: zsh detects rm * but not rm ** (multiple stars)

[Amm <ammdispose-zsh@xxxxxxxxx>]

On 03/13/2014 09:49 PM, Bart Schaefer wrote:

> On Mar 13,  5:26pm, Amm wrote:
> } Subject: zsh detects rm * but not rm ** (multiple stars)
> }
> } But I suppose match should not just be on single *
> } but on *+ (1 or more *)
>
> Thanks for the suggestion.  The "rm *" behavior is very old (was in
> the shell even before the special meaning of "**", something over 20
> years ago now) and hasn't changed in all that time, so I can't say
> with any confidence it'll change now.

Umm, I think it should be changed.

I have tried to fix this. I have attached a patch to exec.c file,

Patch is very small. It does not change logic. Just extends the check to 
checkriskyglob() function.

Currently checkriskyglob() checks for glob containing / and *.

So it will match / OR */ OR **/  OR */* OR **/* OR **/** so on

In future it may be extended to check other patterns which can cause 
accidental destruction.


> } Also is there a way to make zsh warn when there is * in
> } argument list, regardless of command?
>
> I think most people would just find this annoying :-)


I doubt it would be annoying because:

1) I dont think good administrator would ever use * directly for any 
command (Its better to be very specific by simply pressing *<TAB> - 
which will expand star to ALL files)

2) If one still feels annoyed then just like RM_STAR_SILENT|WAIT we can 
add CMD_STAR_SILENT/WAIT.

Only difference is that CMD_STAR_SILENT would be enabled by default and 
CMD_STAR_WAIT would be disabled by default.

So existing behaviour will continue by default but anyone who wants 
functionality I wanted, can activate accordingly.


> This behaves the way you wanted, aborting the entire command on any
> "no" answer (but leaving it in the editor for you to fix, which you
> didn't ask for but seemed reasonable).

Great thanks a lot. You have always been of great help.

Amm

--- exec.c.old	2014-03-14 10:31:32.071645866 +0530
+++ exec.c	2014-03-14 10:53:35.616798543 +0530
@@ -2351,6 +2351,18 @@
 }
 
 /**/
+static int
+checkriskyglob(const char *s)
+{
+    if (!s) return 0;
+    while (s[0] == Star || s[0] == '/') {
+        if (!s[1]) return 1;
+        ++s;
+    } 
+    return 0;
+}
+
+/**/
 static void
 execcmd(Estate state, int input, int output, int how, int last1)
 {
@@ -2729,20 +2741,18 @@
 	LinkNode node, next;
 
 	for (node = nextnode(firstnode(args)); node && !errflag; node = next) {
-	    char *s = (char *) getdata(node);
+	    char *rs, *s = (char *) getdata(node);
 	    int l = strlen(s);
 
 	    next = nextnode(node);
-	    if (s[0] == Star && !s[1]) {
+	    if (checkriskyglob(s)) {
 		if (!checkrmall(pwd))
 		    uremnode(args, node);
-	    } else if (l > 2 && s[l - 2] == '/' && s[l - 1] == Star) {
-		char t = s[l - 2];
-
-		s[l - 2] = 0;
+	    } else if (l > 2 && (rs = strrchr(l, '/')) && checkriskyglob(rs+1)) {
+		*rs = 0;
 		if (!checkrmall(s))
 		    uremnode(args, node);
-		s[l - 2] = t;
+		*rs = '/';
 	    }
 	}
 	if (!nextnode(firstnode(args)))