Format error messages properly

Make use of strerror(errno) and format all errors equally:
function ['parameters']: error message

1 files changed, 9 insertions, 8 deletions

diff --git a/components/swap.c b/components/swap.c
index b82ff46..f3bbeb2 100644
--- a/components/swap.c
+++ b/components/swap.c
@@ -1,5 +1,6 @@
 /* See LICENSE file for copyright and license details. */
 #if defined(__linux__)
+#include <errno.h>
 #include <stdio.h>
 #include <string.h>
 
@@ -15,12 +16,12 @@ swap_free(void)
 
 	fp = fopen("/proc/meminfo", "r");
 	if (fp == NULL) {
-		fprintf(stderr, "Failed to open file /proc/meminfo");
+		fprintf(stderr, "fopen '/proc/meminfo': %s\n", strerror(errno));
 		return NULL;
 	}
 
 	if ((bytes_read = fread(buf, sizeof(char), sizeof(buf) - 1, fp)) == 0) {
-		fprintf(stderr, "swap_free: read error");
+		fprintf(stderr, "fread '/proc/meminfo': %s\n", strerror(errno));
 		fclose(fp);
 		return NULL;
 	}
@@ -47,12 +48,12 @@ swap_perc(void)
 
 	fp = fopen("/proc/meminfo", "r");
 	if (fp == NULL) {
-		fprintf(stderr, "Failed to open file /proc/meminfo");
+		fprintf(stderr, "fopen '/proc/meminfo': %s\n", strerror(errno));
 		return NULL;
 	}
 
 	if ((bytes_read = fread(buf, sizeof(char), sizeof(buf) - 1, fp)) == 0) {
-		fprintf(stderr, "swap_perc: read error");
+		fprintf(stderr, "fread '/proc/meminfo': %s\n", strerror(errno));
 		fclose(fp);
 		return NULL;
 	}
@@ -83,11 +84,11 @@ swap_total(void)
 
 	fp = fopen("/proc/meminfo", "r");
 	if (fp == NULL) {
-		fprintf(stderr, "Failed to open file /proc/meminfo");
+		fprintf(stderr, "fopen '/proc/meminfo': %s\n", strerror(errno));
 		return NULL;
 	}
 	if ((bytes_read = fread(buf, sizeof(char), sizeof(buf) - 1, fp)) == 0) {
-		fprintf(stderr, "swap_total: read error");
+		fprintf(stderr, "fread '/proc/meminfo': %s\n", strerror(errno));
 		fclose(fp);
 		return NULL;
 	}
@@ -110,11 +111,11 @@ swap_used(void)
 
 	fp = fopen("/proc/meminfo", "r");
 	if (fp == NULL) {
-		fprintf(stderr, "Failed to open file /proc/meminfo");
+		fprintf(stderr, "fopen '/proc/meminfo': %s\n", strerror(errno));
 		return NULL;
 	}
 	if ((bytes_read = fread(buf, sizeof(char), sizeof(buf) - 1, fp)) == 0) {
-		fprintf(stderr, "swap_used: read error");
+		fprintf(stderr, "fread '/proc/meminfo': %s\n", strerror(errno));
 		fclose(fp);
 		return NULL;
 	}