set_program_name(), error(): New functions

6 files changed, 93 insertions, 14 deletions

diff --git a/src/image.c b/src/image.c
index e55f955..59716da 100644
--- a/src/image.c
+++ b/src/image.c
@@ -49,8 +49,7 @@ image_new(const char *file_name)
 	if (strcmp(file_name, "-") != 0) {
 		image->fp = fopen(file_name, "wb");
 		if (!image->fp) {
-			printf(_("Error: Cannot open \"%s\" for writing\n"),
-					file_name);
+			error(_("Cannot open \"%s\" for writing"), file_name);
 			return image_destroy(&image);
 		}
 	}
diff --git a/src/image.h b/src/image.h
index ece53f7..be3b66d 100644
--- a/src/image.h
+++ b/src/image.h
@@ -27,6 +27,7 @@
 #include <string.h>
 
 #include "font.h"
+#include "output.h"
 
 #define IMAGE_BIT_DEPTH  8
 #define IMAGE_CHANNELS   3
diff --git a/src/local.mk b/src/local.mk
index 24d8af2..27ceddb 100644
--- a/src/local.mk
+++ b/src/local.mk
@@ -2,5 +2,6 @@ fbcon2png_SOURCES += \
 	%reldir%/font.c \
 	%reldir%/image.c \
 	%reldir%/main.c \
+	%reldir%/output.c \
 	%reldir%/sgr.c \
 	%reldir%/text.c
diff --git a/src/main.c b/src/main.c
index e6fdada..cd7b04a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -26,6 +26,7 @@
 #include "font.h"
 #include "i18n.h"
 #include "image.h"
+#include "output.h"
 #include "text.h"
 
 static void
@@ -54,6 +55,8 @@ main(int argc, char **argv)
 	struct text  *text;
 	struct image *image;
 
+	set_program_name(argv[0]);
+
 	font = NULL;
 	w = 0;
 	h = 0;
@@ -66,8 +69,7 @@ main(int argc, char **argv)
 				}
 				font = font_find(optarg);
 				if (!font) {
-					fprintf(stderr, _("Font \"%s\" not "
-								"found\n"),
+					error(_("Font \"%s\" not found"),
 							optarg);
 					usage(stderr, argv[0]);
 					return 1;
@@ -76,10 +78,9 @@ main(int argc, char **argv)
 			case 'w':
 				w = strtol(optarg, &end, 10);
 				if (*optarg == '\0' || *end != '\0' || w <= 0) {
-					fprintf(stderr, _("Width must be an "
-								"integer "
-								"greater than "
-								"0\n"));
+					error(_("Width must be an integer "
+								"greater than 0"
+								));
 					usage(stderr, argv[0]);
 					return 1;
 				}
@@ -87,10 +88,9 @@ main(int argc, char **argv)
 			case 'h':
 				h = strtol(optarg, &end, 10);
 				if (*optarg == '\0' || *end != '\0' || h <= 0) {
-					fprintf(stderr, _("Height must be an "
-								"integer "
-								"greater than "
-								"0\n"));
+					error(_("Height must be an integer "
+								"greater than 0"
+								));
 					usage(stderr, argv[0]);
 					return 1;
 				}
@@ -113,8 +113,8 @@ main(int argc, char **argv)
 	if (strcmp(input, "-") != 0) {
 		fp = fopen(input, "r");
 		if (!fp) {
-			fprintf(stderr, _("Error: Cannot open \"%s\" for "
-						"reading\n"), input);
+			error(_("Error: Cannot open \"%s\" for reading"),
+					input);
 			return 1;
 		}
 	} else {
diff --git a/src/output.c b/src/output.c
new file mode 100644
index 0000000..0d8341c
--- /dev/null
+++ b/src/output.c
@@ -0,0 +1,47 @@
+/*
+ * Program output functions
+ *
+ * Copyright (C) 2019  Patrick McDermott
+ *
+ * This file is part of fbcon2png.
+ *
+ * fbcon2png is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * fbcon2png is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with fbcon2png.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "output.h"
+
+#include <stdarg.h>
+#include <stdio.h>
+
+#include "i18n.h"
+
+static const char *_program_name;
+
+void
+set_program_name(const char *name)
+{
+	_program_name = name;
+}
+
+void
+error(const char *format, ...)
+{
+	va_list ap;
+
+	fprintf(stderr, _("%s: Error: "), _program_name);
+	va_start(ap, format);
+	vfprintf(stderr, format, ap);
+	va_end(ap);
+	fputs("\n", stderr);
+}
diff --git a/src/output.h b/src/output.h
new file mode 100644
index 0000000..a2c83b5
--- /dev/null
+++ b/src/output.h
@@ -0,0 +1,31 @@
+/*
+ * Program output functions
+ *
+ * Copyright (C) 2019  Patrick McDermott
+ *
+ * This file is part of fbcon2png.
+ *
+ * fbcon2png is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * fbcon2png is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with fbcon2png.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef OUTPUT_H_
+#define OUTPUT_H_
+
+void
+set_program_name(const char *name);
+
+void
+error(const char *format, ...) __attribute__((format(gnu_printf, 1, 2)));
+
+#endif  /* OUTPUT_H_ */