From 35684c08a8429cf1c1148c74d2df8cdf4c31bbac Mon Sep 17 00:00:00 2001
From: Nick Bowler <nbowler@draconx.ca>
Date: Sat, 13 Mar 2021 18:53:31 -0500
Subject: [PATCH] Improve cdecl99 error output.

Ensure that printed error messages are appropriately prefixed,
and mark some missed strings as translateable.
---
 src/cdecl99.c     | 29 ++++++++++++++++++++++++-----
 src/cdecl99.h     |  2 ++
 src/commands.c    |  4 ++--
 src/execute.gperf |  3 +--
 4 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/src/cdecl99.c b/src/cdecl99.c
index 2a522d4..27ce048 100644
--- a/src/cdecl99.c
+++ b/src/cdecl99.c
@@ -25,6 +25,7 @@
 #include <errno.h>
 #include <locale.h>
 #include <assert.h>
+#include <stdarg.h>
 
 #include <getopt.h>
 #include <gettext.h>
@@ -37,6 +38,7 @@
 #include "cdecl.h"
 
 static const char *progname = "cdecl99";
+static bool interactive = true;
 
 #include "options.h"
 static const char sopts[] = SOPT_STRING;
@@ -45,6 +47,21 @@ static const struct option lopts[] = {
 	{0}
 };
 
+void print_error(const char *fmt, ...)
+{
+	va_list(ap);
+
+	if (!interactive)
+		fprintf(stderr, "%s: ", progname);
+	fprintf(stderr, "%s", _("error: "));
+
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+
+	fprintf(stderr, "\n");
+}
+
 static void print_version(void)
 {
 	const char *copysign = "(C)";
@@ -236,8 +253,7 @@ static int repl_noninteractive(void)
 	free(line);
 
 	if (ferror(stdin)) {
-		errno = saved_errno;
-		perror("read error");
+		print_error("%s", strerror(saved_errno));
 		return -1;
 	}
 
@@ -257,7 +273,7 @@ static void init_i18n(void)
 
 int main(int argc, char **argv)
 {
-	bool show_intro = true, interactive = true, execute = false;
+	bool show_intro = true, execute = false;
 	const char *filename = NULL;
 	int i, opt, rc;
 
@@ -296,7 +312,9 @@ int main(int argc, char **argv)
 	}
 
 	if (optind < argc) {
-		fprintf(stderr, _("%s: excess command-line arguments:"),
+		fprintf(stderr, "%s: ", progname);
+
+		fprintf(stderr, _("excess command-line arguments:"),
 		                progname);
 		for (i = optind; i < argc; i++) {
 			fprintf(stderr, " %s", argv[i]);
@@ -317,7 +335,8 @@ int main(int argc, char **argv)
 	/* --execute supersedes --filename */
 	if (filename && !execute) {
 		if (!freopen(filename, "r", stdin)) {
-			perror(filename);
+			print_error("failed to open %s: %s\n", filename,
+			                                strerror(errno));
 			return EXIT_FAILURE;
 		}
 	}
diff --git a/src/cdecl99.h b/src/cdecl99.h
index e1030d4..254b29f 100644
--- a/src/cdecl99.h
+++ b/src/cdecl99.h
@@ -28,6 +28,8 @@ int run_command_simplify(const char *arg);
 int run_command_explain(const char *arg);
 int run_command_declare(const char *cmdarg);
 
+void print_error(const char *fmt, ...);
+
 #if HAVE_RL_ADD_HISTORY && HAVE_READLINE_HISTORY_H
 #  include <readline/history.h>
 #else
diff --git a/src/commands.c b/src/commands.c
index d435f50..dea4219 100644
--- a/src/commands.c
+++ b/src/commands.c
@@ -45,7 +45,7 @@ retry:
 
 		tmp = realloc(buf, rc + 1);
 		if (!tmp) {
-			fprintf(stderr, "%s\n", _("failed to allocate memory"));
+			print_error("%s", _("failed to allocate memory)"));
 			return NULL;
 		}
 
@@ -67,7 +67,7 @@ int run_command_explain(const char *arg)
 	decl = cdecl_parse_decl(arg);
 	if (!decl) {
 		err = cdecl_get_error();
-		fprintf(stderr, "%s\n", err->str);
+		print_error("%s", err->str);
 		goto out;
 	}
 
diff --git a/src/execute.gperf b/src/execute.gperf
index 5f6740e..b1e7d59 100644
--- a/src/execute.gperf
+++ b/src/execute.gperf
@@ -94,8 +94,7 @@ int run_command(const char *line, int interactive)
 
 	c = in_word_set(cmd, arg-cmd);
 	if (!c) {
-		fprintf(stderr, _("unknown command %.*s\n"),
-		                (int)(arg-cmd), cmd);
+		print_error(_("unknown command %.*s"), (int)(arg-cmd), cmd);
 		if (interactive) {
 			fprintf(stderr, "%s\n",
 			        _("Try \"help\" for a list of possible commands."));
-- 
2.43.0