rssg: fix date formatting

use RSSG_DATE_IMPL environmental variable to set date(1) flavour of your
choice.

1 files changed, 15 insertions, 2 deletions

diff --git a/bin/rssg b/bin/rssg
index 099fe67..2d22a1a 100755
--- a/bin/rssg
+++ b/bin/rssg
@@ -2,6 +2,7 @@
 #
 # https://www.romanzolotarev.com/bin/rssg
 # Copyright 2018 Roman Zolotarev <hi@romanzolotarev.com>
+# Copyright 2022 la-ninpre <aaoth@aaoth.xyz>
 #
 # Permission to use, copy, modify, and/or distribute this software for any
 # purpose with or without fee is hereby granted, provided that the above
@@ -18,6 +19,7 @@
 set -e
 set -x
 
+[ -z "$RSSG_DATE_IMPL" ] && RSSG_DATE_IMPL="GNU"
 
 main () {
 	test -n "$1" || usage
@@ -118,8 +120,19 @@ rel_to_abs_urls() {
 
 
 date_rfc_822() {
-	date '+%a, %d %b %Y %H:%M:%S %z' \
-	"$(echo "$1"| tr -cd '[:digit:]')0000"
+    _format='+%a, %d %b %Y %H:%M:%S %z'
+    _date="$1"
+    case "$RSSG_DATE_IMPL" in
+        "BSD")
+            _date="$(echo "$1" | tr -cd '[:digit:]')0000"
+            date -j "$_format" "$_date"
+            ;;
+        "GNU")
+            date -d "$_date" "$_format"
+            ;;
+        *)
+            ;;
+    esac
 }