libbb: new option FEATURE_ETC_SERVICES: if off, /etc/services reads often avoided

In practice, "wget http://host.com/" always uses port 80.
People explicitly set non-standard ports via options or parameters
("telnet 1.2.3.4 567" or "telnet 1.2.3.4 ftp") instead of modifying
/etc/services.

function                                             old     new   delta
telnet_main                                         1466    1464      -2
rdate_main                                           215     198     -17
fakeidentd_main                                      269     252     -17
parse_url                                            459     392     -67
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/4 up/down: 0/-103)           Total: -103 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
2018-04-17 12:43:54 +02:00
parent 816d8d7a66
commit 2aeb201c97
6 changed files with 25 additions and 7 deletions

View File

@ -45,7 +45,7 @@ static time_t askremotedate(const char *host)
alarm(10);
signal(SIGALRM, socket_timeout);
fd = create_and_connect_stream_or_die(host, bb_lookup_port("time", "tcp", 37));
fd = create_and_connect_stream_or_die(host, bb_lookup_std_port("time", "tcp", 37));
if (safe_read(fd, &nett, 4) != 4) /* read time from server */
bb_error_msg_and_die("%s: %s", host, "short read");