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, 7 insertions, 5 deletions

diff --git a/modutils/modinfo.c b/modutils/modinfo.c
index ee379304c..8e74b6438 100644
--- a/modutils/modinfo.c
+++ b/modutils/modinfo.c
@@ -62,7 +62,7 @@ static void modinfo(const char *path, const char *version,
                 "firmware",
         };
         size_t len;
-        int j, length;
+        int j;
         char *ptr, *the_module;
         const char *field = env->field;
         int tags = env->tags;
@@ -94,16 +94,18 @@ static void modinfo(const char *path, const char *version,
                 pattern = field;
                 if ((1<<j) & OPT_TAGS)
                         pattern = shortcuts[j];
-                length = strlen(pattern);
                 ptr = the_module;
                 while (1) {
+                        char *after_pattern;
+
                         ptr = memchr(ptr, *pattern, len - (ptr - (char*)the_module));
                         if (ptr == NULL) /* no occurance left, done */
                                 break;
-                        if (strncmp(ptr, pattern, length) == 0 && ptr[length] == '=') {
+                        after_pattern = is_prefixed_with(ptr, pattern);
+                        if (after_pattern && *after_pattern == '=') {
                                 /* field prefixes are 0x80 or 0x00 */
-                                if ((ptr[-1] & 0x7F) == '\0') {
-                                        ptr += length + 1;
+                                if ((ptr[-1] & 0x7F) == 0x00) {
+                                        ptr = after_pattern + 1;
                                         display(ptr, pattern, (1<<j) != tags);
                                         ptr += strlen(ptr);
                                 }