Index: openacs-4/packages/assessment/tcl/as-qti-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/assessment/tcl/as-qti-procs.tcl,v
diff -u -r1.50.2.3 -r1.50.2.4
--- openacs-4/packages/assessment/tcl/as-qti-procs.tcl	8 Aug 2020 11:19:23 -0000	1.50.2.3
+++ openacs-4/packages/assessment/tcl/as-qti-procs.tcl	21 May 2021 07:40:57 -0000	1.50.2.4
@@ -21,7 +21,7 @@
         # Create a temporary directory
         file mkdir $tmpdirectory
         # UNZIP the zip file in the temporary directory
-        catch { exec unzip ${tmp_dir} -d $tmpdirectory } outMsg
+        util::unzip -source ${tmp_dir} -destination $tmpdirectory
 
         set url_assessment {}
         # Read the content of the temporary directory
@@ -53,7 +53,7 @@
         # Create a temporary directory
         file mkdir $tmpdirectory
         # UNZIP the zip file in the temporary directory
-        catch { exec unzip ${tmp_dir} -d $tmpdirectory } outMsg
+        util::unzip -source ${tmp_dir} -destination $tmpdirectory
 
         set assessment_id {}
         # Read the content of the temporary directory
Index: openacs-4/packages/assessment/www/asm-admin/unzip-file.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/assessment/www/asm-admin/unzip-file.tcl,v
diff -u -r1.5 -r1.5.2.1
--- openacs-4/packages/assessment/www/asm-admin/unzip-file.tcl	7 Aug 2017 23:48:04 -0000	1.5
+++ openacs-4/packages/assessment/www/asm-admin/unzip-file.tcl	21 May 2021 07:40:56 -0000	1.5.2.1
@@ -22,7 +22,7 @@
 file mkdir $tmpdirectory
 
 # UNZIP the zip file in the temporary directory
-catch { exec unzip ${zipfile.tmpfile} -d $tmpdirectory } outMsg
+util::unzip -source ${zipfile.tmpfile} -destination $tmpdirectory
 
 # Read the content of the temporary directory
 foreach file_i [ glob -directory $tmpdirectory *{.xml}  ] {
Index: openacs-4/packages/file-storage/www/folder-zip-add.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/file-storage/www/folder-zip-add.tcl,v
diff -u -r1.11.2.7 -r1.11.2.8
--- openacs-4/packages/file-storage/www/folder-zip-add.tcl	31 Mar 2021 11:32:54 -0000	1.11.2.7
+++ openacs-4/packages/file-storage/www/folder-zip-add.tcl	21 May 2021 07:40:55 -0000	1.11.2.8
@@ -141,6 +141,11 @@
     # Uncompress the file.
     #
     set unzip_binary [string trim [parameter::get -parameter UnzipBinary]]
+    if {$unzip_binary ne ""} {
+        ns_log warning "package parameter UnzipBinary of file-storage is ignored, using systemwide util::unzip"
+    }
+    
+    set unzip_binary [util::which unzip]
     if { $unzip_binary ne "" } {
         #
         # Create temp directory to unzip.
@@ -151,19 +156,14 @@
         #
         # Unzip.
         #
-        # More flexible parameter design could be:
-        # zip {unzip -jd {out_path} {in_file}} tar {tar xf {in_file} {out_path}} tgz {tar xzf {in_file} {out_path}}
-        #
-        # save paths! get rid of -j switch --DAVEB 20050628
-        #
-        catch { exec $unzip_binary -d $unzip_path ${upload_file.tmpfile} } errmsg
+        util::unzip -source ${upload_file.tmpfile} -destination $unzip_path
 
         #
         # Get two lists of the files to upload, with and without their full path.
         #
         set upload_files [list]
         set upload_tmpfiles [list]
-        foreach file [ad_find_all_files "$unzip_path"] {
+        foreach file [ad_find_all_files $unzip_path] {
             lappend upload_files [regsub "^$unzip_path\/" $file {}]
             lappend upload_tmpfiles $file
         }
Index: openacs-4/packages/richtext-ckeditor4/tcl/richtext-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/richtext-ckeditor4/tcl/richtext-procs.tcl,v
diff -u -r1.14.2.12 -r1.14.2.13
--- openacs-4/packages/richtext-ckeditor4/tcl/richtext-procs.tcl	16 Dec 2020 18:55:43 -0000	1.14.2.12
+++ openacs-4/packages/richtext-ckeditor4/tcl/richtext-procs.tcl	21 May 2021 07:40:57 -0000	1.14.2.13
@@ -378,7 +378,7 @@
         #
         foreach url [dict get $resource_info downloadURLs] {
             set fn [file tail $url]
-            set output [exec $unzip -o $resourceDir/$version/$fn -d $resourceDir/$version]
+            util::unzip -overwrite -source $resourceDir/$version/$fn -destination $resourceDir/$version
             file rename -- \
                 $resourceDir/$version/ckeditor \
                 $resourceDir/$version/$ck_package