PATCH: _tar (autodetection of compression by GNU tar >= 1.14.91)

PATCH: _tar (autodetection of compression by GNU tar >= 1.14.91)

[Clint Adams]

Since version 1.14.91, GNU tar has autodetected compressed
archives.

Index: Completion/Unix/Command/_tar
===================================================================
RCS file: /cvsroot/zsh/zsh/Completion/Unix/Command/_tar,v
retrieving revision 1.3
diff -u -r1.3 _tar
--- Completion/Unix/Command/_tar	27 Feb 2003 09:29:26 -0000	1.3
+++ Completion/Unix/Command/_tar	24 Jun 2006 19:24:54 -0000
@@ -21,6 +21,8 @@
 # from some of the possible long options, and from the second word if
 # that does not start with a hyphen.
 
+_pick_variant gnu=GNU unix --version
+
 tmp=("${(@M)words:#-[^-]*}")
 _tar_cmd="${(j::)tmp#-}"
 
Index: Completion/Unix/Type/_tar_archive
===================================================================
RCS file: /cvsroot/zsh/zsh/Completion/Unix/Type/_tar_archive,v
retrieving revision 1.3
diff -u -r1.3 _tar_archive
--- Completion/Unix/Type/_tar_archive	21 Jan 2004 13:53:29 -0000	1.3
+++ Completion/Unix/Type/_tar_archive	24 Jun 2006 19:24:54 -0000
@@ -18,6 +18,8 @@
     _files "$expl[@]" -g '*.((tar|TAR).(gz|GZ|Z)|tgz)(-.)'
   elif [[ "$1" = *[Ijy]* ]]; then
     _files "$expl[@]" -g '*.(tar|TAR).bz2(-.)'
+  elif [[ "$_cmd_variant[$service]" == gnu ]]; then
+    _files "$expl[@]" -g '*.((tar|TAR).(gz|GZ|Z|bz2)|tgz)(-.)'
   else
     _files "$expl[@]" -g '*.(tar|TAR)(-.)'
   fi

Re: PATCH: _tar (autodetection of compression by GNU tar >= 1.14.91)

[Bart Schaefer]

On Jun 24,  3:26pm, Clint Adams wrote:
}
} Since version 1.14.91, GNU tar has autodetected compressed
} archives.

I'm not entirely certain this patch is a good idea.  It doesn't
really hurt to have a completer offer things like command-line
options for the latest version of a program, but to complete a
file that an older version won't know what to do with is a bit
worse.

What proportion of zsh users can be expected to have the latest
version of tar?  There is not one single machine where I use zsh
where this completion would be correct, because all of them have
GNU tar but the latest is 1.14.10 (and most are much older).

Re: PATCH: _tar (autodetection of compression by GNU tar >= 1.14.91)

[Clint Adams]

> I'm not entirely certain this patch is a good idea.  It doesn't
> really hurt to have a completer offer things like command-line
> options for the latest version of a program, but to complete a
> file that an older version won't know what to do with is a bit
> worse.

How about this?

Index: Completion/Unix/Command/_tar
===================================================================
RCS file: /cvsroot/zsh/zsh/Completion/Unix/Command/_tar,v
retrieving revision 1.4
diff -u -r1.4 _tar
--- Completion/Unix/Command/_tar	24 Jun 2006 19:28:55 -0000	1.4
+++ Completion/Unix/Command/_tar	24 Jun 2006 20:13:34 -0000
@@ -21,7 +21,13 @@
 # from some of the possible long options, and from the second word if
 # that does not start with a hyphen.
 
-_pick_variant gnu=GNU unix --version
+if _pick_variant gnu=GNU unix --version; then
+  case "$($service --version)" in
+    (tar \(GNU tar\) (#b)([0-9.-]##)*)
+    is_at_least 1.14.91 "$match[1]" || _cmd_variant[$service]="gnu-old"
+    ;;
+  esac
+fi
 
 tmp=("${(@M)words:#-[^-]*}")
 _tar_cmd="${(j::)tmp#-}"

Re: PATCH: _tar (autodetection of compression by GNU tar >= 1.14.91)

[Bart Schaefer]

On Jun 24,  4:14pm, Clint Adams wrote:
} 
} How about this?

Except that is_at_least may not be autoloaded yet at that point, it
looks OK.  (I like the trick of putting a backreference in the case
pattern.)

Re: PATCH: _tar (autodetection of compression by GNU tar >= 1.14.91)

[Oliver Kiddle]

Clint Adams wrote:
> 
> How about this?

> +    is_at_least 1.14.91 "$match[1]" || _cmd_variant[$service]="gnu-old"

You should use the -r option to _pick_variant. The use of the
_cmd_variant associative array for a cache is really an internal
implementation detail of _pick_variant. Also, if we ever have
namespaces, it'd be renamed.

Oliver