libbb: add strncpy_IFNAMSIZ

function                                             old     new   delta
...
udhcp_read_interface                                 225     220      -5
brctl_main                                          1151    1146      -5
add_interface                                        109     104      -5
ipaddr_list_or_flush                                2174    2167      -7
do_add_ioctl                                          88      80      -8
vconfig_main                                         249     240      -9
do_del_ioctl                                          78      68     -10
do_iplink                                           1186    1173     -13
do_if_fetch                                          766     753     -13
buffer_fill_and_print                                196     179     -17
parse_args                                          1709    1684     -25
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/20 up/down: 11/-140)         Total: -129 bytes

1 files changed, 1 insertions, 0 deletions

diff --git a/include/libbb.h b/include/libbb.h
index 77c4c6088..e4ccc7573 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -540,6 +540,7 @@ char *xstrdup(const char *s) FAST_FUNC;
 char *xstrndup(const char *s, int n) FAST_FUNC;
 void overlapping_strcpy(char *dst, const char *src) FAST_FUNC;
 char *safe_strncpy(char *dst, const char *src, size_t size) FAST_FUNC;
+char *strncpy_IFNAMSIZ(char *dst, const char *src) FAST_FUNC;
 /* Guaranteed to NOT be a macro (smallest code). Saves nearly 2k on uclibc.
  * But potentially slow, don't use in one-billion-times loops */
 int bb_putchar(int ch) FAST_FUNC;