libbb: introduce and use is_prefixed_with()

function                                             old     new   delta
is_prefixed_with                                       -      18     +18
complete_username                                     78      77      -1
man_main                                             737     735      -2
fsck_device                                          429     427      -2
unpack_ar_archive                                     80      76      -4
strip_unsafe_prefix                                  105     101      -4
singlemount                                         1054    1050      -4
rtc_adjtime_is_utc                                    90      86      -4
resolve_mount_spec                                    88      84      -4
parse_one_line                                      1029    1025      -4
parse_conf                                          1460    1456      -4
may_wakeup                                            83      79      -4
loadkmap_main                                        219     215      -4
get_irqs_from_stat                                   103      99      -4
get_header_cpio                                      913     909      -4
findfs_main                                           79      75      -4
fbsplash_main                                       1230    1226      -4
load_crontab                                         776     771      -5
expand_vars_to_list                                 1151    1146      -5
date_main                                            881     876      -5
skip_dev_pfx                                          30      24      -6
make_device                                         2199    2193      -6
complete_cmd_dir_file                                773     767      -6
run_applet_and_exit                                  715     708      -7
uudecode_main                                        321     313      -8
pwdx_main                                            197     189      -8
execute                                              568     560      -8
i2cdetect_main                                      1186    1176     -10
procps_scan                                         1242    1230     -12
procps_read_smaps                                   1017    1005     -12
process_module                                       746     734     -12
patch_main                                          1903    1891     -12
nfsmount                                            3572    3560     -12
stack_machine                                        126     112     -14
process_timer_stats                                  449     435     -14
match_fstype                                         111      97     -14
do_ipaddr                                           1344    1330     -14
open_list_and_close                                  359     343     -16
get_header_tar                                      1795    1779     -16
prepend_new_eth_table                                340     323     -17
fsck_main                                           1811    1794     -17
find_iface_state                                      56      38     -18
dnsd_main                                           1321    1303     -18
base_device                                          179     158     -21
find_keyword                                         104      82     -22
handle_incoming_and_exit                            2785    2762     -23
parse_and_put_prompt                                 774     746     -28
modinfo                                              347     317     -30
find_action                                          204     171     -33
update_passwd                                       1470    1436     -34
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/49 up/down: 18/-540)         Total: -522 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 5 insertions, 5 deletions

diff --git a/networking/ifupdown.c b/networking/ifupdown.c
index c35d97a1a..daabeec0c 100644
--- a/networking/ifupdown.c
+++ b/networking/ifupdown.c
@@ -289,7 +289,7 @@ static char *parse(const char *command, struct interface_defn_t *ifd)
                                         /* "hwaddress <class> <address>":
                                          * unlike ifconfig, ip doesnt want <class>
                                          * (usually "ether" keyword). Skip it. */
-                                        if (strncmp(command, "hwaddress", 9) == 0) {
+                                        if (is_prefixed_with(command, "hwaddress")) {
                                                 varvalue = skip_whitespace(skip_non_whitespace(varvalue));
                                         }
 # endif
@@ -298,7 +298,7 @@ static char *parse(const char *command, struct interface_defn_t *ifd)
 # if ENABLE_FEATURE_IFUPDOWN_IP
                                         /* Sigh...  Add a special case for 'ip' to convert from
                                          * dotted quad to bit count style netmasks.  */
-                                        if (strncmp(command, "bnmask", 6) == 0) {
+                                        if (is_prefixed_with(command, "bnmask")) {
                                                 unsigned res;
                                                 varvalue = get_var("netmask", 7, ifd);
                                                 if (varvalue) {
@@ -1159,12 +1159,12 @@ static char *run_mapping(char *physical, struct mapping_defn_t *map)
 
 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
 {
-        unsigned iface_len = strlen(iface);
         llist_t *search = state_list;
 
         while (search) {
-                if ((strncmp(search->data, iface, iface_len) == 0)
-                 && (search->data[iface_len] == '=')
+                char *after_iface = is_prefixed_with(search->data, iface);
+                if (after_iface
+                 && *after_iface == '='
                 ) {
                         return search;
                 }