redis作爲一個服務器，它的啓動是從main函數開始的。redis.c
1. 進程重命名
#ifdef INIT_SETPROCTITLE_REPLACEMENT spt_init(argc, argv); #endif
定義在config.h
/* Check if we can use setproctitle(). 修改進程名稱 * BSD systems have support for it, we provide an implementation for * Linux and osx. */ #if (defined __NetBSD__ || defined __FreeBSD__ || defined __OpenBSD__) //bsd（unix的變種）宏定義 #define USE_SETPROCTITLE #endif #if (defined __linux || defined __APPLE__) //linux和蘋果的宏定義 #define USE_SETPROCTITLE #define INIT_SETPROCTITLE_REPLACEMENT void spt_init(int argc, char *argv[]); void setproctitle(const char *fmt, ...); #endif
http://www.baike.com/wiki/BSD
BSD的開源後裔
不同的BSD操作系統針對不同的用途及用戶，可應用於多種硬件構架。在政府機構中常能看到BSD的身影。雖然下面的BSD功能可能並非獨有，但每種BSD在各自的領域，都逐漸具有了良好聲譽，有的專注於性能，有的則以安全見長。
DragonflyBSD是最年輕的BSD，專門提供比FreeBSD更優秀的對稱多處理機系統，並使內核直接支持SSI集羣，以取得更好的計算效果。這個項目在此方向上，纔開始數年，主要關注i386平臺。
FreeBSD在BSD家族中以易用性與高性能而着稱，由於主要用作微處理器架構，如i386、AMD's 64-bit i386擴展，所以FreeBSD非常關注多處理器。FreeBSD在i386和amd64服務器上，運行地非常好，當然，它也可以在其他硬件構架上運行。
NetBSD擁有特別出色的可移植性，能在多達54種平臺上運行，小到嵌入式的掌上設備，大到服務器羣，NetBSD甚至還在國際空間站中服務。
OpenBSD在密碼學和安全方面特別出衆，可移植性也很好，當然略遜於NetBSD。安全功能如OpenSSH，是由OpenBSD率先開創的。OpenBSD作爲安全請求機器（security demanding machines）運行，受到好評。
必須注意的是，上面所羅列的，更多地是基於感性認識，並針對其開發焦點，並沒有嚴格地比較規則。實際而言，每種具體的BSD都可擔當許多角色任務。
2. 設置locale
setlocale(LC_COLLATE,"");
http://manpages.ubuntu.com/manpages/lucid/en/man3/setlocale.3.html
NAME
setlocale - set the current locale
SYNOPSIS
#include <locale.h>
char *setlocale(int category, const char *locale);
DESCRIPTION
The setlocale() function is used to set or query the program’s current
locale.
If locale is not NULL, the program’s current locale is modified
according to the arguments. The argument category determines which
parts of the program’s current locale should be modified.
LC_ALL for all of the locale.
LC_COLLATE
for regular expression matching (it determines the meaning of
range expressions and equivalence classes) and string collation.
LC_CTYPE
for regular expression matching, character classification,
conversion, case-sensitive comparison, and wide character
functions.
LC_MESSAGES
for localizable natural-language messages.
LC_MONETARY
for monetary formatting.
LC_NUMERIC
for number formatting (such as the decimal point and the
thousands separator).
LC_TIME
for time and date formatting.
The argument locale is a pointer to a character string containing the
required setting of category. Such a string is either a well-known
constant like "C" or "da_DK" (see below), or an opaque string that was
returned by another call of setlocale().
If locale is "", each part of the locale that should be modified is set
according to the environment variables. The details are
implementation-dependent. For glibc, first (regardless of category),
the environment variable LC_ALL is inspected, next the environment
variable with the same name as the category (LC_COLLATE, LC_CTYPE,
LC_MESSAGES, LC_MONETARY, LC_NUMERIC, LC_TIME) and finally the
environment variable LANG. The first existing environment variable is
used. If its value is not a valid locale specification, the locale is
unchanged, and setlocale() returns NULL.
The locale "C" or "POSIX" is a portable locale; its LC_CTYPE part
corresponds to the 7-bit ASCII character set.
A locale name is typically of the form
language[_territory][.codeset][@modifier], where language is an ISO 639
language code, territory is an ISO 3166 country code, and codeset is a
character set or encoding identifier like ISO-8859-1 or UTF-8. For a
list of all supported locales, try "locale -a", cf. locale(1).
If locale is NULL, the current locale is only queried, not modified.
On startup of the main program, the portable "C" locale is selected as
default. A program may be made portable to all locales by calling:
setlocale(LC_ALL, "");
after program initialization, by using the values returned from a
localeconv(3) call for locale-dependent information, by using the
multi-byte and wide character functions for text processing if
MB_CUR_MAX > 1, and by using strcoll(3), wcscoll(3) or strxfrm(3),
wcsxfrm(3) to compare strings.
RETURN VALUE
A successful call to setlocale() returns an opaque string that
corresponds to the locale set. This string may be allocated in static
storage. The string returned is such that a subsequent call with that
string and its associated category will restore that part of the
process’s locale. The return value is NULL if the request cannot be
honored.
CONFORMING TO
C89, C99, POSIX.1-2001.
NOTES
Linux (that is, glibc) supports the portable locales "C" and "POSIX".
In the good old days there used to be support for the European Latin-1
"ISO-8859-1" locale (e.g., in libc-4.5.21 and libc-4.6.27), and the
Russian "KOI-8" (more precisely, "koi-8r") locale (e.g., in
libc-4.6.27), so that having an environment variable
LC_CTYPE=ISO-8859-1 sufficed to make isprint(3) return the right
answer. These days non-English speaking Europeans have to work a bit
harder, and must install actual locale files.
SEE ALSO
locale(1), localedef(1), isalpha(3), localeconv(3), nl_langinfo(3), rpmatch(3), strcoll(3), strftime(3), charsets(7), locale(7)
COLOPHON
This page is part of release 3.23 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.
