Date formatting doesn't take locale in account.

[lowusage]

Currently, date formatting doesn't take the current locale in account.
For example, this file :

#date %d %B %Y

Will produce the following outputs :

$ ./src/gpp test.gpp 
11 May 2026
$ LANG=fr_FR.utf8 ./src/gpp test.gpp 
11 May 2026
$ LC_ALL=fr_FR.utf8 ./src/gpp test.gpp 
11 May 2026

Instead of the correct localized outputs.

The expected output being :

$ ./src/gpp test.gpp 
11 May 2026
$ LANG=fr_FR.utf8 ./src/gpp test.gpp 
11 mai 2026
$ LC_ALL=fr_FR.utf8 ./src/gpp test.gpp 
11 mai 2026

This is an easy fix : include the locale C header and use setlocale(LC_ALL, "") at initialization. The attached patch does that (I don't exactly know if initthings() is the right place through).

Thanks.

0001-Fix-localization-support.patch

From d41e09dc44bad94a167f05dfa1df5faf5f507296 Mon Sep 17 00:00:00 2001
From: lzigmann <laura@zigmann.org>
Date: Mon, 11 May 2026 13:04:49 +0200
Subject: [PATCH] Fix localization support

Signed-off-by: lzigmann <laura@zigmann.org>
---
 src/gpp.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/gpp.c b/src/gpp.c
index 1ade1fa..9ee79bd 100644
--- a/src/gpp.c
+++ b/src/gpp.c
@@ -44,6 +44,7 @@
 #  include <fnmatch.h>
 #endif
 #include <time.h>
+#include <locale.h>
 
 #define STACKDEPTH 50
 #define MAXARGS 100
@@ -1247,6 +1248,9 @@ void initthings(int argc, char **argv) {
     autoswitch = 0;
     dosmode = DEFAULT_CRLF;
 
+    /* set locale global state for date formating */
+    setlocale(LC_ALL, "");
+
     for (arg = argv + 1; *arg; arg++) {
         if (!endofoptions && strcmp(*arg, "--") == 0) {
             endofoptions = 1;
-- 
2.47.3

EDIT: example outputs takes place on a system with "C" as its default locale.
EDIT2: added patch as plain text content