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>

7 files changed, 18 insertions, 18 deletions

diff --git a/networking/dnsd.c b/networking/dnsd.c
index fe98400f7..923ad6bc6 100644
--- a/networking/dnsd.c
+++ b/networking/dnsd.c
@@ -194,7 +194,7 @@ static char *table_lookup(struct dns_entry *d,
 		if ((len != 1 || d->name[1] != '*')
 		/* we assume (do not check) that query_string
 		 * ends in ".in-addr.arpa" */
-		 && strncmp(d->rip, query_string, strlen(d->rip)) == 0
+		 && is_prefixed_with(query_string, d->rip)
 		) {
 #if DEBUG
 			fprintf(stderr, "Found name:%s\n", d->name);
diff --git a/networking/httpd.c b/networking/httpd.c
index 9cf080401..7a9065fcc 100644
--- a/networking/httpd.c
+++ b/networking/httpd.c
@@ -697,7 +697,7 @@ static void parse_conf(const char *path, int flag)
 				goto config_error;
 			}
 			*host_port++ = '\0';
-			if (strncmp(host_port, "http://", 7) == 0)
+			if (is_prefixed_with(host_port, "http://"))
 				host_port += 7;
 			if (*host_port == '\0') {
 				goto config_error;
@@ -1894,7 +1894,7 @@ static Htaccess_Proxy *find_proxy_entry(const char *url)
 {
 	Htaccess_Proxy *p;
 	for (p = proxy; p; p = p->next) {
-		if (strncmp(url, p->url_from, strlen(p->url_from)) == 0)
+		if (is_prefixed_with(url, p->url_from))
 			return p;
 	}
 	return NULL;
@@ -2183,7 +2183,7 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
 			if (STRNCASECMP(iobuf, "Range:") == 0) {
 				/* We know only bytes=NNN-[MMM] */
 				char *s = skip_whitespace(iobuf + sizeof("Range:")-1);
-				if (strncmp(s, "bytes=", 6) == 0) {
+				if (is_prefixed_with(s, "bytes=") == 0) {
 					s += sizeof("bytes=")-1;
 					range_start = BB_STRTOOFF(s, &s, 10);
 					if (s[0] != '-' || range_start < 0) {
@@ -2269,7 +2269,7 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
 	tptr = urlcopy + 1;      /* skip first '/' */
 
 #if ENABLE_FEATURE_HTTPD_CGI
-	if (strncmp(tptr, "cgi-bin/", 8) == 0) {
+	if (is_prefixed_with(tptr, "cgi-bin/")) {
 		if (tptr[8] == '\0') {
 			/* protect listing "cgi-bin/" */
 			send_headers_and_exit(HTTP_FORBIDDEN);
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;
 		}
diff --git a/networking/inetd.c b/networking/inetd.c
index 8148925ce..dce5a0885 100644
--- a/networking/inetd.c
+++ b/networking/inetd.c
@@ -727,7 +727,7 @@ static NOINLINE servtab_t *parse_one_line(void)
 			goto parse_err;
 #endif
 		}
-		if (strncmp(arg, "rpc/", 4) == 0) {
+		if (is_prefixed_with(arg, "rpc/")) {
 #if ENABLE_FEATURE_INETD_RPC
 			unsigned n;
 			arg += 4;
diff --git a/networking/libiproute/ipaddress.c b/networking/libiproute/ipaddress.c
index aa4779ad1..4072d0626 100644
--- a/networking/libiproute/ipaddress.c
+++ b/networking/libiproute/ipaddress.c
@@ -701,7 +701,7 @@ static int ipaddr_modify(int cmd, char **argv)
 		/* There was no "dev IFACE", but we need that */
 		bb_error_msg_and_die("need \"dev IFACE\"");
 	}
-	if (l && strncmp(d, l, strlen(d)) != 0) {
+	if (l && !is_prefixed_with(l, d)) {
 		bb_error_msg_and_die("\"dev\" (%s) must match \"label\" (%s)", d, l);
 	}
 
diff --git a/networking/nameif.c b/networking/nameif.c
index 9a8846dc0..9b18a6d16 100644
--- a/networking/nameif.c
+++ b/networking/nameif.c
@@ -161,19 +161,19 @@ static void nameif_parse_selector(ethtable_t *ch, char *selector)
 		if (*next)
 			*next++ = '\0';
 		/* Check for selectors, mac= is assumed */
-		if (strncmp(selector, "bus=", 4) == 0) {
+		if (is_prefixed_with(selector, "bus=")) {
 			ch->bus_info = xstrdup(selector + 4);
 			found_selector++;
-		} else if (strncmp(selector, "driver=", 7) == 0) {
+		} else if (is_prefixed_with(selector, "driver=")) {
 			ch->driver = xstrdup(selector + 7);
 			found_selector++;
-		} else if (strncmp(selector, "phyaddr=", 8) == 0) {
+		} else if (is_prefixed_with(selector, "phyaddr=")) {
 			ch->phy_address = xatoi_positive(selector + 8);
 			found_selector++;
 		} else {
 #endif
 			lmac = xmalloc(ETH_ALEN);
-			ch->mac = ether_aton_r(selector + (strncmp(selector, "mac=", 4) != 0 ? 0 : 4), lmac);
+			ch->mac = ether_aton_r(selector + (is_prefixed_with(selector, "mac=") ? 4 : 0), lmac);
 			if (ch->mac == NULL)
 				bb_error_msg_and_die("can't parse %s", selector);
 #if  ENABLE_FEATURE_NAMEIF_EXTENDED
diff --git a/networking/netstat.c b/networking/netstat.c
index f80b845bc..02f4cc7cc 100644
--- a/networking/netstat.c
+++ b/networking/netstat.c
@@ -228,12 +228,12 @@ static long extract_socket_inode(const char *lname)
 {
 	long inode = -1;
 
-	if (strncmp(lname, "socket:[", sizeof("socket:[")-1) == 0) {
+	if (is_prefixed_with(lname, "socket:[")) {
 		/* "socket:[12345]", extract the "12345" as inode */
 		inode = bb_strtoul(lname + sizeof("socket:[")-1, (char**)&lname, 0);
 		if (*lname != ']')
 			inode = -1;
-	} else if (strncmp(lname, "[0000]:", sizeof("[0000]:")-1) == 0) {
+	} else if (is_prefixed_with(lname, "[0000]:")) {
 		/* "[0000]:12345", extract the "12345" as inode */
 		inode = bb_strtoul(lname + sizeof("[0000]:")-1, NULL, 0);
 		if (errno) /* not NUL terminated? */