diff --git a/update-pytorch.sh b/update-pytorch.sh
index 141890a..b2d936b 100755
--- a/update-pytorch.sh
+++ b/update-pytorch.sh
@@ -1,26 +1,26 @@
 #!/bin/bash
 
-# old non-updated compute platforms:
-# cu75 cu80 cu90 cu91 cu92 cu100 cu101 cu102 cu110 cu111 cu113 cu115 cu116 cu117 cu117_pypi_cudnn
-# rocm3.10 rocm3.7 rocm3.8 rocm4.0.1 rocm4.1 rocm4.2 rocm4.3.1 rocm4.5.2 rocm5.0 rocm5.1.1 rocm5.2 rocm5.3 rocm5.4.2 rocm5.5 rocm5.6 rocm5.7
-for d in . cpu cpu-cxx11-abi cpu_pypi_pkg cu118 cu121 cu124 rocm6.0 rocm6.1
-do
-  d="whl/$d"
-  [ "$d" == "whl/." ] && d="whl"
+# update a PyPI index from PyTorch = https://download.pytorch.org/$d with d=whl or whl/<compute platform>
+# this copies the content (main url + follows links to projects) and does 2 updates:
+# 1. copies the content in a "simple/" sub-directory to match the convention from PEP 503 simple (that allows other APIs in parallel)
+# 2. updates the links to binary packages by adding "https://download.pytorch.org" prefix to PyTorch-provided "/whl/*" path to link back to PyTorch binaries in their home location
+function updateIndex() {
+  local d=$1
+
+  # will copy source $d to $d/simple
   mkdir -p $d/simple
-  dir="$(pwd)"
+  local dir="$(pwd)"
   cd $d/simple
+
+  # projects list
   curl -s https://download.pytorch.org/$d/ | grep -v 'TIMESTAMP 1' > index.html
-  count="$(cat index.html | cut -d '>' -f 2 | cut -d '<' -f 1 | grep -cve '^\s*$')"
+  local count="$(cat index.html | cut -d '>' -f 2 | cut -d '<' -f 1 | grep -cve '^\s*$')"
 
-  echo "https://download.pytorch.org/$d/ $count => $d/simple/"
-  if [ $count -lt 40 ]
-  then
-    echo "failing because low packages count for $d: $count (intermittent download failure?)"
-    exit 1
-  fi
+  echo "https://download.pytorch.org/$d/ => $d/simple/"
+  checkCount $d $count 40
 
-  i=0
+  # copy also content of each project
+  local i=0
   for p in `cat index.html | cut -d '>' -f 2 | cut -d '<' -f 1`
   do
     mkdir -p $p
@@ -31,20 +31,51 @@ do
       | grep -v 'TIMESTAMP 1' \
       > index.html
 
-    count="$(cat index.html | grep -c 'https://download.pytorch.org/whl/')"
-    echo "$i                            $d/$p/ => $d/simple/$p/ $count"
-    if [ $count -lt 1 ]
-    then
-      echo "failing because low packages count for $d/$p: $count (intermittent download failure?)"
-      exit 1
-    fi
+    local pcount="$(cat index.html | grep -c 'https://download.pytorch.org/whl/')"
+    printf "%5d / $count                   $d/$p/ => $d/simple/$p/ $pcount\n" $i
+    checkCount $d/$p $count 1
     cd ..
   done
   echo
   cd "$dir"
+}
+
+function checkCount() {
+  local content="$1"
+  local count="$2"
+  local minimum="$3"
+
+  if [ $count -lt $minimum ]
+  then
+    echo "!!! failing because low packages count for $content: $count (probably intermittent download failure)"
+    exit 1
+  fi
+}
+
+# update main PyTorch index, that contains everything, whatever the compute platform
+updateIndex "whl"
+
+# see resulting updates
+git update-index -q --refresh
+git diff-index --name-status HEAD
+
+if `git diff-index --quiet HEAD`
+then
+  echo "no update found in PyTorch main index."
+  exit 0
+fi
+echo "updates found in PyTorch main index: updating also compute platform specific ones..."
+
+# update compute-platform specific indexes
+# ignore old non-updated ones:
+# - cu75 cu80 cu90 cu91 cu92 cu100 cu101 cu102 cu110 cu111 cu113 cu115 cu116 cu117 cu117_pypi_cudnn
+# - rocm3.10 rocm3.7 rocm3.8 rocm4.0.1 rocm4.1 rocm4.2 rocm4.3.1 rocm4.5.2 rocm5.0 rocm5.1.1 rocm5.2 rocm5.3 rocm5.4.2 rocm5.5 rocm5.6 rocm5.7
+for d in cpu cpu-cxx11-abi cpu_pypi_pkg cu118 cu121 cu124 rocm6.0 rocm6.1
+do
+  updateIndex "whl/$d"
 done
 
 du -sh whl/*
 
-for d in whl/simple whl/*/simple ; do echo "$(ls $d | wc -l) $d" ; done > summary.txt
+for d in whl/simple whl/*/simple ; do echo "$(ls $d | wc -l | xargs) $d" ; done > summary.txt
 cat summary.txt