From 3a21b9b19034b09c704db66ba35ed1038e739eba Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Wed, 4 Jan 2023 16:14:51 -0800
Subject: [PROPOSED] Prefer fprintf+strerror to perror

* date.c (main):
* zdump.c (tzalloc, gmtzinit, main): Improve quality of
diagnostics by using strerror and fprintf with suitable formatting
strings, rather than perror which is less flexible.
---
 date.c  |  4 +++-
 zdump.c | 11 ++++++++---
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/date.c b/date.c
index 5819aa0e..b62f04d7 100644
--- a/date.c
+++ b/date.c
@@ -86,7 +86,9 @@ main(const int argc, char *argv[])
 			else if (! (TIME_T_MIN <= secs && secs <= TIME_T_MAX))
 				errno = ERANGE;
 			if (errno) {
-				perror(optarg);
+				char const *e = strerror(errno);
+				fprintf(stderr, _("date: %s: %s\n"),
+					optarg, e);
 				errensure();
 				exit(retval);
 			}
diff --git a/zdump.c b/zdump.c
index b93910ed..0e759d61 100644
--- a/zdump.c
+++ b/zdump.c
@@ -253,7 +253,8 @@ tzalloc(char const *val)
 {
 # if HAVE_SETENV
   if (setenv("TZ", val, 1) != 0) {
-    perror("setenv");
+    char const *e = strerror(errno);
+    fprintf(stderr, _("%s: setenv: %s\n"), progname, e);
     exit(EXIT_FAILURE);
   }
   tzset();
@@ -332,7 +333,9 @@ gmtzinit(void)
       static char const gmt0[] = "GMT0";
       gmtz = tzalloc(gmt0);
       if (!gmtz) {
-	perror(gmt0);
+	char const *e = strerror(errno);
+	fprintf(stderr, _("%s: unknown timezone '%s': %s\n"),
+		progname, gmt0, e);
 	exit(EXIT_FAILURE);
       }
     }
@@ -597,7 +600,9 @@ main(int argc, char *argv[])
 		struct tm tm, newtm;
 		bool tm_ok;
 		if (!tz) {
-		  perror(argv[i]);
+		  char const *e = strerror(errno);
+		  fprintf(stderr, _("%s: unknown timezone '%s': %s\n"),
+			  progname, argv[1], e);
 		  return EXIT_FAILURE;
 		}
 		if (now) {
-- 
2.37.2