utils-std

commit: cb63c7b5437116d5f79c83c400f2e79aa324b75d
parent d3e79ea42c4d17fde77f719c79d4763ddc74dad8
Author: Haelwenn (lanodan) Monnier <contact@hacktivis.me>
Date:   Fri, 20 Sep 2024 03:33:48 +0200

cmd/nproc: unify error message formatting

Diffstat:
M
cmd/nproc.c
16
++++++++++++----

1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/cmd/nproc.c b/cmd/nproc.c
@@ -2,12 +2,17 @@
 // SPDX-FileCopyrightText: 2017 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
 // SPDX-License-Identifier: MPL-2.0
 
-// _SC_NPROCESSORS_CONF &_SC_NPROCESSORS_ONLN aren't in POSIX yet but have been accepted
+// _SC_NPROCESSORS_CONF &_SC_NPROCESSORS_ONLN got added in POSIX.1-2024
 // https://www.austingroupbugs.net/view.php?id=339
 #define _DEFAULT_SOURCE
+#define _POSIX_C_SOURCE 202405L
+#include <errno.h>
 #include <stdio.h>  // printf
+#include <string.h> // strerror
 #include <unistd.h> // sysconf, getopt, opt*
 
+const char *argv0 = "nproc";
+
 static void
 usage(void)
 {
@@ -19,6 +24,7 @@ main(int argc, char *argv[])
 {
 	// currently available
 	int target = _SC_NPROCESSORS_ONLN;
+	const char *target_str = "_SC_NPROCESSORS_ONLN";
 
 	int c = -1;
 	while((c = getopt(argc, argv, ":a")) != -1)
@@ -27,13 +33,14 @@ main(int argc, char *argv[])
 		{
 		case 'a': // can be made available
 			target = _SC_NPROCESSORS_CONF;
+			target_str = "_SC_NPROCESSORS_CONF";
 			break;
 		case ':':
-			fprintf(stderr, "nproc: Error: Missing operand for option: '-%c'\n", optopt);
+			fprintf(stderr, "%s: error: Missing operand for option: '-%c'\n", argv0, optopt);
 			usage();
 			return 1;
 		case '?':
-			fprintf(stderr, "nproc: Error: Unrecognised option: '-%c'\n", optopt);
+			fprintf(stderr, "%s: error: Unrecognised option: '-%c'\n", argv0, optopt);
 			usage();
 			return 1;
 		}
@@ -42,7 +49,8 @@ main(int argc, char *argv[])
 	long np = sysconf(target);
 	if(np < 0)
 	{
-		perror("nproc: sysconf");
+		fprintf(
+		    stderr, "%s: error: Failed getting sysconf '%s': %s\n", argv0, target_str, strerror(errno));
 		return 1;
 	}