Reduce libc.so's memory footprint by lazily allocating memory used internally

by basename() and dirname().
Reviewed by: eric

2 files changed, 16 insertions, 4 deletions

diff --git a/lib/libc/gen/basename.c b/lib/libc/gen/basename.c
index cbeb1d5..9bd2dc2 100644
--- a/lib/libc/gen/basename.c
+++ b/lib/libc/gen/basename.c
@@ -42,9 +42,15 @@ char *
 basename(path)
 	const char *path;
 {
-	static char bname[MAXPATHLEN];
+	static char *bname = NULL;
 	const char *endp, *startp;
 
+ 	if (bname == NULL) {
+		bname = (char *)malloc(MAXPATHLEN);
+		if (bname == NULL)
+			return(NULL);
+	}
+
 	/* Empty or NULL string gets treated as "." */
 	if (path == NULL || *path == '\0') {
 		(void)strcpy(bname, ".");
@@ -67,7 +73,7 @@ basename(path)
 	while (startp > path && *(startp - 1) != '/')
 		startp--;
 
-	if (endp - startp + 2 > sizeof(bname)) {
+	if (endp - startp + 2 > MAXPATHLEN) {
 		errno = ENAMETOOLONG;
 		return(NULL);
 	}
diff --git a/lib/libc/gen/dirname.c b/lib/libc/gen/dirname.c
index 8e287af..4e5ecb4 100644
--- a/lib/libc/gen/dirname.c
+++ b/lib/libc/gen/dirname.c
@@ -42,9 +42,15 @@ char *
 dirname(path)
 	const char *path;
 {
-	static char bname[MAXPATHLEN];
+	static char *bname = NULL;
 	const char *endp;
 
+	if (bname == NULL) {
+		bname = (char *)malloc(MAXPATHLEN);
+		if (bname == NULL)
+			return(NULL);
+	}
+
 	/* Empty or NULL string gets treated as "." */
 	if (path == NULL || *path == '\0') {
 		(void)strcpy(bname, ".");
@@ -70,7 +76,7 @@ dirname(path)
 		} while (endp > path && *endp == '/');
 	}
 
-	if (endp - path + 2 > sizeof(bname)) {
+	if (endp - path + 2 > MAXPATHLEN) {
 		errno = ENAMETOOLONG;
 		return(NULL);
 	}