1 files changed, 21 insertions, 14 deletions
diff --git a/libc/stdio/perror.c b/libc/stdio/perror.c
index d6274c056..04cd688d8 100644
--- a/libc/stdio/perror.c
+++ b/libc/stdio/perror.c
@@ -1,19 +1,26 @@
-#include <unistd.h>
-#include <string.h>
+#include <stdio.h>
 #include <errno.h>
 
-void perror(str)
-__const char *str;
-{
-	register char *ptr;
+/*
+ * Manuel Novoa III           Feb 2001
+ *
+ * Replaced old version that did write(2,...)'s with a version using
+ * stream functions.  If the program is calling perror, it's a safe
+ * bet that printf and friends are used as well.  It is also possible
+ * that the calling program could buffer stderr, or reassign it.
+ * Also, the old version did not conform the standards when the 
+ * passed char * was either NULL or pointed to an empty string.
+ */
 
-	if (str) {
-		write(2, str, strlen(str));
-		write(2, ": ", 2);
-	} else
-		write(2, "perror: ", 8);
+void perror(__const char *str)
+{
+	static const char perror_str[] = ": ";
+	const char *sep;
 
-	ptr = strerror(errno);
-	write(2, ptr, strlen(ptr));
-	write(2, "\n", 1);
+	sep = perror_str;
+	if (!(str && *str)) {		/* Caller did not supply a prefix message */
+		sep += 2;				/* or passed an empty string. */
+		str = sep;
+	}
+	fprintf(stderr, "%s%s%s\n", str, sep, strerror(errno));
 }