mknod: Factor out error printing

2 files changed, 47 insertions, 55 deletions

diff --git a/configure.ac b/configure.ac
index ad067cc..28e5d94 100644
--- a/configure.ac
+++ b/configure.ac
@@ -43,11 +43,12 @@ test -d "${srcdir}/.git" || CFLAGS="${save_CFLAGS}"
 funcs_missing=false
 AC_CHECK_FUNCS(
 	[\
-		calloc execve fclose fdopen feof ferror fopen fprintf fputs \
-		fread free fscanf fseek fwrite getgrgid getpwuid localtime \
-		lstat malloc memcmp memcpy memset mkdir mkfifo open printf \
-		puts readlink rename scandir sleep snprintf sprintf stat \
-		strchr strcmp strcpy strftime strlen strncpy strtol unlink
+		calloc execve fclose fdopen feof ferror fopen fprintf fputc \
+		fputs fread free fscanf fseek fwrite getgrgid getpwuid \
+		localtime lstat malloc memcmp memcpy memset mkdir mkfifo open \
+		printf puts readlink rename scandir sleep snprintf sprintf \
+		stat strchr strcmp strcpy strftime strlen strncpy strtol \
+		unlink vfprintf
 	],
 	[],
 	[funcs_missing=true])
@@ -62,6 +63,9 @@ fi
 AC_CHECK_DECLS([[major(dev_t)], [minor(dev_t)]], [],
 	[AC_MSG_ERROR([required macros are missing])],
 	[#include <sys/sysmacros.h>])
+AC_CHECK_DECLS([[va_start(ap, last)], [va_end(ap)]], [],
+	[AC_MSG_ERROR([required macros are missing])],
+	[#include <stdarg.h>])
 
 PKG_PROG_PKG_CONFIG()
 PKG_CHECK_MODULES([ZLIB], [zlib])
diff --git a/helpers/mknod.c b/helpers/mknod.c
index ef7ce98..58b0b03 100644
--- a/helpers/mknod.c
+++ b/helpers/mknod.c
@@ -21,6 +21,7 @@
 
 #include <errno.h>
 #include <fcntl.h>
+#include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -57,6 +58,18 @@ static const unsigned int _TIMEOUT = 10U;
 
 static char *_program_name;
 
+static void __attribute__((format(__printf__, 1, 2)))
+_err(const char *fmt, ...)
+{
+	va_list ap;
+
+	fprintf(stderr, "%s: ", _program_name);
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+	fputc('\n', stderr);
+}
+
 static int
 _strtol_or_err(const char *str, long int *l)
 {
@@ -64,8 +77,7 @@ _strtol_or_err(const char *str, long int *l)
 
 	*l = strtol(str, &end, 10);
 	if (*end != '\0') {
-		fprintf(stderr, _("%s: Invalid number \"%s\"\n"),
-				_program_name, str);
+		_err(_("Invalid number \"%s\""), str);
 		return OPKG_OPK_ERROR;
 	}
 	return OPKG_OPK_OK;
@@ -104,23 +116,18 @@ main(int argc, char *argv[])
 
 	work_area = getenv("OPK_WORK_AREA");
 	if (work_area == NULL || work_area[0] == '\0') {
-		fprintf(stderr, _("%s: OPK_WORK_AREA environment variable not "
-					"set\n"), _program_name);
-		fprintf(stderr, _("%s: Possibly building package dependent on "
-					"opkg-opk with opkbuild too old to use "
-					"it\n"), _program_name);
-		fprintf(stderr, _("%s: Executing system mknod instead\n"),
-			_program_name);
+		_err(_("OPK_WORK_AREA environment variable not set"));
+		_err(_("Possibly building package dependent on opkg-opk with "
+					"opkbuild too old to use it"));
+		_err(_("Executing system mknod instead"));
 		exec_argv = calloc(argc + 1, sizeof(*exec_argv));
 		if (exec_argv == NULL) {
-			fprintf(stderr, _("%s: Failed to allocate memory\n"),
-					_program_name);
+			_err(_("Failed to allocate memory"));
 			return EXIT_FAILURE;
 		}
 		exec_argv[0] = malloc(strlen(MKNOD) + 1);
 		if (exec_argv[0] == NULL) {
-			fprintf(stderr, _("%s: Failed to allocate memory\n"),
-					_program_name);
+			_err(_("Failed to allocate memory"));
 			free(exec_argv);
 			return EXIT_FAILURE;
 		}
@@ -130,8 +137,7 @@ main(int argc, char *argv[])
 		}
 		exec_argv[argc] = NULL;
 		execve(MKNOD, exec_argv, NULL);  /* Shouldn't return */
-		fprintf(stderr, _("%s: Failed to execute system mknod\n"),
-				_program_name);
+		_err(_("Failed to execute system mknod"));
 		free(exec_argv[0]);
 		free(exec_argv);
 		return EXIT_FAILURE;
@@ -151,16 +157,13 @@ main(int argc, char *argv[])
 				mode = 0666 ^ mode;
 				if (opkg_opk_helper_mode_parse(mode, optarg,
 							&mode) != OPKG_OPK_OK) {
-					fprintf(stderr, _("%s: Invalid mode "
-								"\"%s\"\n"),
-							_program_name, optarg);
+					_err(_("Invalid mode \"%s\""), optarg);
 					return EXIT_FAILURE;
 				}
 				break;
 			default:
-				fprintf(stderr, _("%s: Warning: Unknown option:"
-							" \"%c\"\n"),
-						_program_name, optopt);
+				_err(_("Warning: Unknown option: \"%c\""),
+						optopt);
 				return EXIT_FAILURE;
 		}
 	}
@@ -168,8 +171,7 @@ main(int argc, char *argv[])
 	argv += optind;
 
 	if (argc < 2) {
-		fprintf(stderr, _("%s: Wrong number of operands\n"),
-				_program_name);
+		_err(_("Wrong number of operands"));
 		return EXIT_FAILURE;
 	}
 	name = argv[0];
@@ -183,27 +185,21 @@ main(int argc, char *argv[])
 			break;
 		case 'p':
 			if (argc != 2) {
-				fprintf(stderr, _("%s: Wrong number of "
-							"operands\n"),
-						_program_name);
+				_err(_("Wrong number of operands"));
 				return EXIT_FAILURE;
 			}
 			if (mkfifo(name, mode) != 0) {
-				fprintf(stderr, _("%s: Failed to create link "
-							"\"%s\"\n"),
-						_program_name, name);
+				_err(_("Failed to create link \"%s\""), name);
 				return EXIT_FAILURE;
 			}
 			return EXIT_SUCCESS;
 		default:
-			fprintf(stderr, _("%s: Invalid node type \"%c\"\n"),
-						_program_name, argv[1][0]);
+			_err(_("Invalid node type \"%c\""), argv[1][0]);
 			return EXIT_FAILURE;
 	}
 
 	if (argc != 4) {
-		fprintf(stderr, _("%s: Wrong number of operands\n"),
-				_program_name);
+		_err(_("Wrong number of operands"));
 		return EXIT_FAILURE;
 	}
 	if (_strtol_or_err(argv[2], &major) != OPKG_OPK_OK ||
@@ -214,15 +210,13 @@ main(int argc, char *argv[])
 	specials_file_name = malloc(strlen(work_area) + strlen("/specials")
 			+ 1 /* "\0" */);
 	if (specials_file_name == NULL) {
-		fprintf(stderr, _("%s: Failed to allocate memory\n"),
-				_program_name);
+		_err(_("Failed to allocate memory"));
 		return EXIT_FAILURE;
 	}
 	specials_lock_name = malloc(strlen(work_area) + strlen("/specials~")
 			+ 1 /* "\0" */);
 	if (specials_lock_name == NULL) {
-		fprintf(stderr, _("%s: Failed to allocate memory\n"),
-				_program_name);
+		_err(_("Failed to allocate memory"));
 		free(specials_file_name);
 		return EXIT_FAILURE;
 	}
@@ -234,8 +228,7 @@ main(int argc, char *argv[])
 	 */
 	fd = open(name, O_CREAT | O_EXCL, mode);
 	if (fd < 0 || close(fd) < 0) {
-		fprintf(stderr, _("%s: Failed to create node\n"),
-				_program_name);
+		_err(_("Failed to create node"));
 		free(specials_file_name);
 		free(specials_lock_name);
 		return EXIT_FAILURE;
@@ -249,7 +242,7 @@ main(int argc, char *argv[])
 			goto opened;
 		}
 	}
-	fprintf(stderr, _("%s: Failed to lock specials file\n"), _program_name);
+	_err(_("Failed to lock specials file"));
 	free(specials_file_name);
 	free(specials_lock_name);
 	unlink(name);
@@ -258,8 +251,7 @@ main(int argc, char *argv[])
  opened:
 	specials_file = fdopen(specials_fd, "a");
 	if (specials_file == NULL) {
-		fprintf(stderr, _("%s: Failed to open specials file stream\n"),
-				_program_name);
+		_err(_("Failed to open specials file stream"));
 		close(specials_fd);
 		free(specials_file_name);
 		free(specials_lock_name);
@@ -270,8 +262,7 @@ main(int argc, char *argv[])
 	/* If "specials" doesn't exist, write header. */
 	if (stat(specials_file_name, &stat_buf) != 0) {
 		if (errno != ENOENT) {
-			fprintf(stderr, _("%s: Failed to stat specials file\n"),
-					_program_name);
+			_err(_("Failed to stat specials file"));
 			fclose(specials_file);
 			free(specials_file_name);
 			free(specials_lock_name);
@@ -281,8 +272,7 @@ main(int argc, char *argv[])
 		if (fputs("version=1\n", specials_file) < 0 ||
 				fputs("type     major     minor  name\n",
 					specials_file) < 0) {
-			fprintf(stderr, _("%s: Failed to write specials file\n")
-					, _program_name);
+			_err(_("Failed to write specials file"));
 			fclose(specials_file);
 			free(specials_file_name);
 			free(specials_lock_name);
@@ -292,8 +282,7 @@ main(int argc, char *argv[])
 	}
 	if (fprintf(specials_file, "%c  %8ld  %8ld  %s\n", type, major, minor,
 				name) < 0) {
-		fprintf(stderr, _("%s: Failed to write specials file\n"),
-				_program_name);
+		_err(_("Failed to write specials file"));
 		fclose(specials_file);
 		free(specials_file_name);
 		free(specials_lock_name);
@@ -303,8 +292,7 @@ main(int argc, char *argv[])
 	fclose(specials_file);
 
 	if (rename(specials_lock_name, specials_file_name) != 0) {
-		fprintf(stderr, _("%s: Failed to move specials file\n"),
-				_program_name);
+		_err(_("Failed to move specials file"));
 		free(specials_file_name);
 		free(specials_lock_name);
 		unlink(name);