Add pre-commit, pre-push hooks formally

.hooks/link.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+hooks=(
+    "pre-commit"
+    "pre-push"
+)
+
+for hook in "${hooks[@]}"; do
+    chmod +x .hooks/$hook.sh
+    ln -s -f ../../.hooks/$hook.sh .git/hooks/$hook
+done

.hooks/pre-commit.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+
+# Remove all lines starting with >[! from CARGO_README.md
+sed -i '/^>\[!/d' CARGO_README.md
+
+# Add the modified file to the commit
+git add CARGO_README.md

.hooks/pre-push.sh

@@ -0,0 +1,96 @@
+#!/bin/bash
+
+# Script to be run as part of the github pre-push hook.
+#
+# Checks that, if there is a "version-like" tag being pushed, all the files which are supposed to contain the tag do
+# actually have the correct tag value in them. If they do not, the push is blocked.
+# NB: this does _not_ automatically alter the source files and commit them with the correct tag value, nor prevent the
+# tag to be added to the wrong git commit locally (ie. a commit in which the source files have the wrong tag value).
+# All it does is prevent the developer from pushing the 'bad tags' to remote repositories, giving him/her the chance to
+# manually rectify the situation on the local repo before retrying to push.
+#
+# @todo could this be run as pre-commit hook instead? We have to test if adding a tag does trigger pre-commit hook...
+# @see https://stackoverflow.com/questions/56538621/git-hook-to-check-tag-name
+# @see https://stackoverflow.com/questions/8418071/is-there-a-way-to-check-that-a-git-tag-matches-the-content-of-the-corresponding
+#      for an alternative take (enforcing this with a server-side hook)
+#
+# NB: remember that this can be run within a windows env too, via fe. the tortoisegit or the git-4-win on the cli!
+# git for windows comes with its own copy of common unix utils such as bash, grep. But they are sometimes old and/or
+# buggy compared to what one gets in current linux distros :-(
+#
+# This hook is called with the following parameters:
+#
+# $1 -- Name of the remote to which the push is being done
+# $2 -- URL to which the push is being done
+#
+# If pushing without using a named remote those arguments will be equal.
+#
+# Information about the commits which are being pushed is supplied as lines to
+# the standard input in the form:
+#
+#   <local ref> <local oid> <remote ref> <remote oid>
+
+# We do not abort the push in case there is an error in this script. No `set -e`
+#set -e
+
+# @todo detect if this is run outside git hook, and give a warning plus explain how to pass in $local_ref $local_oid $remote_ref $remote_oid
+# @todo allow a git config parameter to switch on/off a 'verbose mode'
+# @todo we could allow the variables `files` and `version_tag_regexp` to be set via git config parameters instead of hardcoded
+
+# List of files which do contain the version tag
+files='Cargo.toml'
+
+# Regexp use to decide if a git tag is a version label
+version_tag_regexp='^v?[0-9]{1,4}\.[0-9]{1,4}(\.[0-9]{1,4})?'
+
+# Create a string of '0' chars of appropriate length for the current git version
+zero="$(git hash-object --stdin </dev/null | tr '[0-9a-f]' '0')"
+
+echo "Checking commits for version tags before push..."
+
+# check all commits which we are pushing
+while read local_ref local_oid remote_ref remote_oid; do
+    #echo "Checking commit $local_oid ..."
+    # skip ref deletions
+    if [ "$local_oid" != "$zero" ]; then
+        #if [ "$remote_oid" = "$zero" ]; then
+        #    # 'new branch'
+        #    range="$local_oid"
+        #else
+        #    # 'update to existing branch'
+        #    range="$remote_oid..$local_oid"
+        #fi
+        # @todo in case we have a range (see commented out code 2 lines above), should we check more commits?
+        tags="$(git tag --points-at $local_oid)"
+        if [ -n "$tags" ]; then
+            # @todo this will not work predictably if there are 2 version tags attached to the same commit. Which probably
+            #       there should not be anyway. Should we check for that too and abort in case?
+            while IFS= read -r tag; do
+                echo "Found tag: '$tag'..."
+                if [[ "$tag" =~ $version_tag_regexp ]]; then
+                    echo "Tag looks like a version number. Checking if code is matching..."
+                    for file in $files; do
+                        if [ ! -f "$file" ]; then
+                            echo "File is missing: '$file'. Please fix config of github hook script"
+                            exit 2
+                        fi
+                        echo "Looking for '$tag' in '$file'"
+                        # @todo atm if the version tag is f.e. v1.1, any file containing the string "clamav1.10' will
+                        #       match. We should improve this match to avoid such scenarios
+                        # Note: we can not use `-i` as it crashes git-4-win's grep
+                        if grep -F -q "$tag" "$file"; then
+                            :
+                        else
+                            echo "Tag is missing from file '$file'"
+                            exit 1
+                        fi
+                    done
+                    echo "All files ok!"
+                    break 2; # exit from both while loops: no need to check for further tags
+                fi
+            done <<< "$tags"
+        fi
+    fi
+done
+
+exit 0