Add ynh_secure_remove helper

scripts/_common.sh

@@ -131,3 +131,101 @@ ynh_remove_uwsgi_service () {
         ynh_secure_remove --file="/etc/systemd/system/uwsgi-app@$app.service.d"
     fi
 }
+
+
+#=================================================
+
+# Remove a file or a directory securely
+#
+# usage: ynh_secure_remove --file=path_to_remove [--regex=regex to append to $file] [--non_recursive] [--dry_run]
+# | arg: -f, --file - File or directory to remove
+# | arg: -r, --regex - Regex to append to $file to filter the files to remove
+# | arg: -n, --non_recursive - Perform a non recursive rm and a non recursive search with the regex
+# | arg: -d, --dry_run - Do not remove, only list the files to remove
+#
+# Requires YunoHost version 2.6.4 or higher.
+ynh_secure_remove () {
+    # Declare an array to define the options of this helper.
+    local legacy_args=frnd
+    declare -Ar args_array=( [f]=file= [r]=regex= [n]=non_recursive [d]=dry_run )
+    local file
+    local regex
+    local dry_run
+    local non_recursive
+    # Manage arguments with getopts
+    ynh_handle_getopts_args "$@"
+    regex=${regex:-}
+    dry_run=${dry_run:-0}
+    non_recursive=${non_recursive:-0}
+
+    local forbidden_path="
+/var/www \
+/home/yunohost.app"
+
+    # Fail if no argument is provided to the helper.
+    if [ -z "$file" ]
+    then
+        ynh_print_warn --message="ynh_secure_remove called with no argument --file, ignoring."
+        return 0
+    fi
+
+    if [ -n "$regex" ]
+    then
+        if [ -e "$file" ]
+        then
+            if [ $non_recursive -eq 1 ]; then
+                local recursive="-maxdepth 1"
+            else
+                local recursive=""
+            fi
+            # Use find to list the files in $file and grep to filter with the regex
+            files_to_remove="$(find -P "$file" $recursive -name ".." -prune -o -print | grep --extended-regexp "$regex")"
+        else
+            ynh_print_info --message="'$file' wasn't deleted because it doesn't exist."
+            return 0
+        fi
+    else
+        files_to_remove="$file"
+    fi
+
+    # Check each file before removing it
+    while read file_to_remove
+    do
+        if [ -n "$file_to_remove" ]
+        then
+            # Check all forbidden path before removing anything
+            # First match all paths or subpaths in $forbidden_path
+            if [[ "$forbidden_path" =~ "$file_to_remove" ]] || \
+                # Match all first level paths from / (Like /var, /root, etc...)
+                [[ "$file_to_remove" =~ ^/[[:alnum:]]+$ ]] || \
+                # Match if the path finishes by /. Because it seems there is an empty variable
+                [ "${file_to_remove:${#file_to_remove}-1}" = "/" ]
+            then
+                ynh_print_err --message="Not deleting '$file_to_remove' because this path is forbidden !!!"
+
+            # If the file to remove exists
+            elif [ -e "$file_to_remove" ]
+            then
+                if [ $dry_run -eq 1 ]
+                then
+                    ynh_print_warn --message="File to remove: $file_to_remove"
+                else
+                    if [ $non_recursive -eq 1 ]; then
+                        local recursive=""
+                    else
+                        local recursive="--recursive"
+                    fi
+
+                    # Remove a file or a directory
+                    rm --force $recursive "$file_to_remove"
+                fi
+            else
+                # Ignore non existent files with regex, as we likely remove the parent directory before its content is listed.
+                if [ -z "$regex" ]
+                then
+                    ynh_print_info --message="'$file_to_remove' wasn't deleted because it doesn't exist."
+                fi  
+            fi
+        fi
+    done <<< "$(echo "$files_to_remove")"
+}