Support THC secure-delete

Recent Linux distribution uses newer THC secure-delete and
it only supports few options.

src/_srm

@@ -36,8 +36,25 @@
 #
 # ------------------------------------------------------------------------------
 
-local -a opts args
+local -a args
+
 args=(
+  '*::files:->file'
+)
+
+_pick_variant -r variant gnu=gnu thc=THC unix --help
+
+if [[ $variant == "thc" ]]; then
+  args+=(
+    '-d[ignore the two special dot files . and .. on the commandline]'
+    '-f[fast (and insecure mode)]'
+    '*-l[lessens the security. -l for a second time lessons the security even more]'
+    '-r[recursive mode]'
+    '-v[verbose mode]'
+    '-z[wipes the last write with zeros instead of random data]'
+  )
+else
+  args+=(
     '(-f --force)'{-f,--force}'[ignore nonexistent files, never prompt]'
     '(-r --interactive)'{-i,--interactive}'[prompt before any removal]'
     '(-r -R --recursive)'{-r,-R,--recursive}'[remove the contents of directories recursively]'
@@ -45,29 +62,28 @@ args=(
     '(-v --verbose)'{-v,--verbose}'[explain what is being done]'
     '(- *)--help[display help message and exit]'
     '(- *)--version[output version information and exit]'
-  '*::files:->file'
+  )
-)
 
-if _pick_variant gnu=gnu unix --help; then
+  if [[ $variant == "gnu" ]]; then
     args+=(
       '(-x --one-file-system)'{-x,--one-file-system}'[stay within filesystems of files given as arguments]'
       '(-P --openbsd)'{-P,--openbsd}'[overwrite the file 3 times (0xff, 0x00, 0xff)]'
       '(-D --dod)'{-D,--dod}'[overwrite the file with 7 US DoD compliant passes (0xF6, 0x00, 0xFF, random, 0x00, 0xFF, random)]'
       '(-E --doe)'{-E,--doe}'[overwrite the file with 3 US DoE compliant passes (random, random, DoE)]'
     )
-else
+  else
     args+=(
       '(-m --medium)'{-m,--medium}'[overwrite the file with 7 US DoD compliant passes (0xF6, 0x00, 0xFF, random, 0x00, 0xFF, random)]'
       '(-z --zero)'{-z,--zero}'[after overwriting, zero blocks used by file]'
       '(-n --nounlink)'{-n,--nounlink}'[overwrite file, but do not rename or unlink it]'
     )
+  fi
 fi
 
 local curcontext=$curcontext state line ret=1
 local -A opt_args
 
-_arguments -s -S -C $opts \
+_arguments -s -S -C $args && ret=0
-  $args && ret=0
 
 case $state in
   (file)
@@ -82,3 +98,11 @@ case $state in
 esac
 
 return $ret
+
+# Local Variables:
+# mode: Shell-Script
+# sh-indentation: 2
+# indent-tabs-mode: nil
+# sh-basic-offset: 2
+# End:
+# vim: ft=zsh sw=2 ts=2 et