[src/trunk]: src/libexec/ld.elf_so Don't use internal libc function __findenv().

[tron <tron%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/02f756e4a322
branches:  trunk
changeset: 758750:02f756e4a322
user:      tron <tron%NetBSD.org@localhost>
date:      Sun Nov 14 22:09:16 2010 +0000

description:
Don't use internal libc function __findenv().

diffstat:

 libexec/ld.elf_so/xenv.c |  29 ++++++++++++++++++++---------
 1 files changed, 20 insertions(+), 9 deletions(-)

diffs (66 lines):

diff -r 8bbc3b4e9c7d -r 02f756e4a322 libexec/ld.elf_so/xenv.c
--- a/libexec/ld.elf_so/xenv.c  Sun Nov 14 22:04:36 2010 +0000
+++ b/libexec/ld.elf_so/xenv.c  Sun Nov 14 22:09:16 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: xenv.c,v 1.1 2010/10/29 15:08:17 christos Exp $        */
+/*     $NetBSD: xenv.c,v 1.2 2010/11/14 22:09:16 tron Exp $    */
 
 /*
  * Copyright (c) 1987, 1993
@@ -34,7 +34,7 @@
 #if 0
 static char sccsid[] = "from: @(#)setenv.c     8.1 (Berkeley) 6/4/93";
 #else
-__RCSID("$NetBSD: xenv.c,v 1.1 2010/10/29 15:08:17 christos Exp $");
+__RCSID("$NetBSD: xenv.c,v 1.2 2010/11/14 22:09:16 tron Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -42,9 +42,10 @@
 #include <string.h>
 #include "rtldenv.h"
 
-extern char * __findenv(const char *, int *);
 extern char **environ;
 
+#include <unistd.h>
+
 /*
  * xunsetenv(name) --
  *     Delete environmental variable "name".
@@ -52,19 +53,29 @@
 int
 xunsetenv(const char *name)
 {
-       int offset;
+       size_t l_name, r_offset, w_offset;
 
-       if (name == NULL || *name == '\0' || strchr(name, '=') != NULL) {
+       if (name == NULL) {
+               errno = EINVAL;
+               return -1;
+       }
+
+       l_name = strcspn(name, "=");
+       if (l_name == 0 || name[l_name] == '=') {
                errno = EINVAL;
                return -1;
        }
 
-       while (__findenv(name, &offset) != NULL) {
-               while (environ[offset] != NULL) {
-                       environ[offset] = environ[offset + 1];
-                       offset++;
+       for (r_offset = 0, w_offset = 0; environ[r_offset] != NULL;
+           r_offset++) {
+               if (strncmp(name, environ[r_offset], l_name) != 0 ||
+                   environ[r_offset][l_name] != '=') {
+                       environ[w_offset++] = environ[r_offset];
                }
        }
 
+       while (w_offset < r_offset)
+               environ[w_offset++] = NULL;
+
        return 0;
 }