Linux CÓïÑÔѧϰ±Ê¼Ç
1¡¢int 4×Ö½Ú
long 8×Ö½Ú
float 4×Ö½Ú
double 8×Ö½Ú
long double 16×Ö½Ú
2¡¢Ò»¸ö×Ö·û±äÁ¿Ö»ÄÜ´æ·ÅÒ»¸ö×Ö·û¡¢Ò»¸ö×Ö½Ú´æ·ÅÒ»¸ö×Ö½Ú
char c;
c = 'a'; c = '\034' c = '\n'
c = '\x65' c = 65 c = 0101
c = 0x41
3¡¢ÔËËã·û²Ù×÷
-i++µÈ¼ÛÓÚ-(i++)
i = 2;
j = -i++;
ÔËËã½á¹ûi=3 j=-2
4¡¢ÓÅÏȼ¶
!Âß¼·Ç > ËãÊõÔËËã·û > ¹ØÏµÔËËã·û > &&Âß¼Óë > ||Âß¼»ò
a = 0; b = 1; c = 2; d = a++&&b++&&--c
µÈ¼ÛÓÚ
a = 0; b = 1; c = 2; d = (a++) && (b++) && (--c)
½á¹ûΪ
a = 1; b = 1; c = 2; d = 0;
a = 0; b = 1; c = 2; d = a++||b++||--c;
µÈ¼ÛÓÚ
a = 0; b = 1; c = 2; d = (a++) || (b++) || (--c);
½á¹ûΪ
a = 1; b = 2; c = 2; d = 1;
5¡¢¸´ºÏ¸³ÖµÔËËã·û
a += b Ï൱ÓÚ a = a + b;
a *= b + c Ï൱ÓÚ a = a * (b + c);
a = 2; a += a *= a; µÈ¼ÛÓÚ a += (a *= a); ×îºóa = 8£»
a = 5; b = 3;
int max = --a == b++ ? a++ : b++;
×îºómax = 4;
6¡¢Ç¿ÖÆÀàÐÍת»»
int a = 2;
int b = 5;
(float)b/aµÈÓÚ2.5
(float)(b/a)µÈÓÚ2.0
7¡¢×Ö·û´®¿½±´º¯Êý
char *strcpy(char *dest, const char *src);
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src¿ÉÒÔÊÇ×Ö·ûÊý×éÃû¡¢³£Á¿»ò×Ö·ûÖ¸Õë±äÁ¿¡£
dest¿ÉÒÔÊÇ×Ö·ûÊý×éÃû»ò×Ö·ûÖ¸Õë±äÁ¿¡£ÈôdestÊÇ×Ö·ûÖ¸Õë±äÁ¿£¬Òª×¢Òâ¸ø¸ÃÖ¸Õë±äÁ¿¸³³õÖµ¡£
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static char a[10] = "abcdefghi";
char b[] = "happy";
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1. HCI²ãÐÒé¸ÅÊö£º
HCIÌṩһÌ×ͳһµÄ·½·¨À´·ÃÎÊBluetoothµ×²ã¡£ÈçͼËùʾ£º
´ÓͼÉÏ¿ÉÒÔ¿´³ö£¬Host Controller Interface(HCI) ¾ÍÊÇÓÃÀ´¹µÍ¨HostºÍModule¡£Hostͨ³£¾ÍÊÇPC£¬ ModuleÔòÊÇÒÔ¸÷ÖÖÎïÀíÁ¬½ÓÐÎʽ£¨USB,serial,pc-cardµÈ£©Á¬½Óµ½PCÉϵÄbluetooth Dongle¡£
ÔÚHostÕâÒ»¶Ë£ºapplication,SDP,L2capµÈÐÒé ......
ÓÐʱÓöµ½ÈçÏÂÎÊÌâ£¬Íø¿¨ÉÏÓиö²æ£¬ÈκÎÃüÁî¶¼ÎÞ·¨ÐÞ¸´¡£
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sudo ifconfig eth0 down
sudo ifconfig eth0 up
sudo /etc/init.d/dhcp3-server restart
sudo /etc/init.d/networking restart
ÎÊÌâ½â¾öºÜ¼òµ¥£¬°ÑÈçϵĸ´Ñ¡¿ò¹´Éϼ´¿É£¬ÐéÄâ»ú¿ª» ......
//»ñÈ¡±¾»úMACµØÖ·º¯ÊýQString GetLocalMac()
{
int sock_mac;
struct ifreq ifr_mac;
char mac_addr[30];
sock_mac = socket( AF_INET, SOCK_STREAM, 0 );
if( sock_mac == -1)
{
perror("create socket falise...mac\n");
return "";
}
memset(&ifr_mac,0,sizeof(ifr_mac));
......
//»ñÈ¡×ÓÍøÑÚÂëµÄº¯ÊýQString GetLocalNetMask()
{
int sock_netmask;
char netmask_addr[50];
struct ifreq ifr_mask;
struct sockaddr_in *net_mask;
sock_netmask = socket( AF_INET, SOCK_STREAM, 0 );
if( sock_netmask == -1)
{
perror("create socket failture...GetLocalNetMask\n");
......