1 files changed, 50 insertions, 11 deletions

diff --git a/libc/string/strerror.c b/libc/string/strerror.c
index 91565965f..3aa8b57e2 100644
--- a/libc/string/strerror.c
+++ b/libc/string/strerror.c
@@ -16,31 +16,70 @@ License along with the GNU C Library; see the file COPYING.LIB.  If
 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
 Cambridge, MA 02139, USA.  */
 
+/*
+ * Manuel Novoa III       Dec 2000
+ *
+ * Converted to use my new (un)signed long (long) to string routines, which
+ * are smaller than the previous functions and don't require static buffers.
+ * Removed dependence on strcat in the process.
+ *
+ * Also appended a test routine ( -DSTRERROR_TEST ) to allow a quick check
+ * on the buffer length when the sys_errorlist is modified.
+ */
+
 #include <stdio.h>
 #include <string.h>
 #include <errno.h>
+#include <limits.h>
+
+#if (INT_MAX >> 31)
+/* We're set up for 32 bit ints */
+#error need to check size allocation for static buffer 'retbuf'
+#endif
 
-extern char *itoa(int);
+extern char *__ltostr(char *buf, long uval, int base, int uppercase);
+
+static char retbuf[33];			/* 33 is sufficient for 32 bit ints */
+static const char unknown_error[] = "Unknown Error: errno"; /* = */
 
 /* Return a string descibing the errno code in ERRNUM.
    The storage is good only until the next call to strerror.
    Writing to the storage causes undefined behavior.  */
 char *strerror(int err)
 {
-	static char retbuf[80];
+	char *pos;
 
-	if (sys_nerr) {
-		if (err < 0 || err >= sys_nerr)
-			goto unknown;
+	if ((err >= 0) && (err < sys_nerr)) {
 		strcpy(retbuf, sys_errlist[err]);
 		return retbuf;
 	}
 
-	if (err <= 0)
-		goto unknown;
+	/* unknown error */
+	pos = __ltostr(retbuf + sizeof(retbuf) + 1, err, 10, 0)
+		- sizeof(unknown_error); /* leave space for the '=' */
+	strcpy(pos, unknown_error);
+	*(pos + sizeof(unknown_error) - 1) = '=';
+	return pos;
+}
+
+#if STRERROR_TEST
+/* quick way to check for sufficient buffer length */
+#include <stdio.h>
+#include <stdlib.h>
+int main(void)
+{
+	int max = 0;
+	int i, j;
+	char *p;
+	for ( i=0 ; i < sys_nerr ; i++ ) {
+		j = strlen(sys_errlist[i])+1;
+		if (j > max) max = j;
+	}
+	printf("max len = %i\n", j);
 
-  unknown:
-	strcpy(retbuf, "Unknown Error: errno=");
-	strcat(retbuf, (char *) itoa(err));
-	return retbuf;
+	p = strerror(INT_MIN);
+	printf("<%s>  %d\n", p, strlen(p)+1);
+	printf("current buffer length is %d\n", sizeof(retbuf));
+	return EXIT_SUCCESS;
 }
+#endif