C/C++——С±à̸CÓïÑÔº¯ÊýÄÇЩÊÂ(6)
C³ÌÐòÊÇÓÉÒ»×é»òÊDZäÁ¿»òÊǺ¯ÊýµÄÍⲿ¶ÔÏó×é³ÉµÄ¡£ º¯ÊýÊÇÒ»¸ö×ÔÎÒ°üº¬µÄÍê³ÉÒ»¶¨Ïà¹Ø¹¦ÄܵÄÖ´ÐдúÂë¶Î¡£ÏÂÃæС±àºÍ´ó¼Ò·ÖÏíÏÂCÓïÑÔÖеĺ¯Êý¡£
1. fcloseº¯Êý
fcloseº¯ÊýµÄ¹¦ÄÜÊǹرÕÒ»¸öÁ÷£¬ÆäÓ÷¨ÊÇ£ºint fclose(FILE *stream); ³ÌÐòÀý×ÓÈçÏ£º
#include <string.h>
#include <stdio.h>
int main(void)
{
FILE *fp;
char buf[11] = "0123456789";
/* create a file containing 10 bytes */
fp = fopen("DUMMY.FIL", "w");
fwrite(&buf, strlen(buf), 1, fp);
/* close the file */
fclose(fp);
return 0;
}
2. fcloseallº¯Êý
fcloseallº¯ÊýµÄ¹¦ÄÜÊǹرմò¿ªÁ÷£¬ÆäÓ÷¨ÊÇ£ºint fcloseall(void); ³ÌÐòÀý×ÓÈçÏ£º
#include <stdio.h>
int main(void)
{
int streams_closed;
/* open two streams */
fopen("DUMMY.ONE", "w");
fopen("DUMMY.TWO", "w");
/* close the open streams */
streams_closed = fcloseall();
if (streams_closed == EOF)
/* issue an error message */
perror("Error");
else
/* print result of fcloseall() function */
printf("%d streams were closed.\n", streams_closed);
return 0;
}
3. fcvtº¯Êý
fcvtº¯ÊýµÄ¹¦ÄÜÊÇ°ÑÒ»¸ö¸¡µãÊýת»»Îª×Ö·û´®£¬ÆäÓ÷¨ÊÇ£ºchar *fcvt(double value, int ndigit, int *decpt, int *sign); ³ÌÐòÀý×ÓÈçÏ£º
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
int main(void)
{
char *string;
double value;
int dec, sign;
int ndig = 10;
clrscr();
value = 9.876;
string = ecvt(value, ndig, &dec, &sign);
printf("string = %s
Ïà¹ØÎĵµ£º
1. ÓÃÔ¤´¦ÀíÖ¸Áî#define ÉùÃ÷Ò»¸ö³£Êý£¬ÓÃÒÔ±íÃ÷1ÄêÖÐÓжàÉÙÃ루ºöÂÔÈòÄêÎÊÌ⣩
#define SECONDS_PER_YEAR (60 * 60 * 24 * 365)UL
ÎÒÔÚÕâÏë¿´µ½¼¸¼þÊÂÇ飺
1). #define Óï·¨µÄ»ù±¾ÖªÊ¶£¨ÀýÈ磺²»ÄÜÒԷֺŽáÊø£¬À¨ºÅµÄʹÓ㬵ȵȣ©
2). ¶®µÃÔ¤´¦ÀíÆ÷½«Î ......
C/C++/VC++ ±äÁ¿ÃüÃû¹æÔò
ÊÇVC++µÄô£¿
4.±äÁ¿·ç¸ñ
±äÁ¿¾¡Á¿²ÉÓÃÐÙÑÀÀûÃüÃû·¨£¬Í¬Ê±½áºÏVCµÄÔÔò£»Ò»°ãÇé¿öÏ£¬±äÁ¿µÄÈ¡Ãû·½Ê½Îª£º
<scope><prefix><qualifier>
ÓйØÏîÄ¿µÄÈ«¾Ö±äÁ¿±ØÐëÓÃg_¿ªÊ¼£¬Àà³ÉÔ±±äÁ¿ÓÃm_£¬¾Ö²¿±äÁ¿Èôº¯Êý½Ï´óÔò¿É¿¼ÂÇÓÃl_ÓÃÒÔÏÔʾ˵Ã÷ÆäÊǾֲ¿±äÁ¿¡£
ǰ׺
ÀàÐÍ
ʾÀý
g_
......
ͻ񻣼
±¾ÎÄ´Ó½éÉÜ»ù´¡¸ÅÄîÈëÊÖ£¬Ì½ÌÖÁËÔÚC/C++ÖжÔÈÕÆÚºÍʱ¼ä²Ù×÷ËùÓõ½µÄÊý¾Ý½á¹¹ºÍº¯Êý£¬²¢¶Ô¼Æʱ¡¢Ê±¼äµÄ»ñÈ¡¡¢Ê±¼äµÄ¼ÆËãºÍÏÔʾ¸ñʽµÈ·½Ãæ½øÐÐÁ˲ûÊö¡£±¾ÎÄ»¹Í¨¹ý´óÁ¿µÄʵÀýÏòÄãչʾÁËtime.hÍ·ÎļþÖÐÉùÃ÷µÄ¸÷ÖÖº¯ÊýºÍÊý¾Ý½á¹¹µÄÏêϸʹÓ÷½·¨¡£
¹Ø¼ü×Ö£ºUTC£¨ÊÀ½ç±ê׼ʱ¼ä£©£¬Calendar Time£¨ÈÕÀúʱ¼ä£©£¬epoch ......
Ò»¸ö¶¨ÒåΪvolatileµÄ±äÁ¿ÊÇ˵Õâ±äÁ¿¿ÉÄܻᱻÒâÏë²»µ½µØ¸Ä±ä£¬ÕâÑù£¬±àÒëÆ÷¾Í²»»áÈ¥¼ÙÉèÕâ¸ö±äÁ¿µÄÖµÁË¡£¾«È·µØ˵¾ÍÊÇ£¬ÓÅ»¯Æ÷ÔÚÓõ½Õâ¸ö±äÁ¿Ê±±ØÐëÿ´Î¶¼Ð¡ÐĵØÖØжÁÈ¡Õâ¸ö±äÁ¿µÄÖµ£¬¶ø²»ÊÇʹÓñ£´æÔڼĴæÆ÷ÀïµÄ±¸·Ý¡£ÏÂÃæÊÇvolatile±äÁ¿µÄ¼¸¸öÀý×Ó£º
1). ²¢ÐÐÉ豸µÄÓ²¼þ¼Ä´æÆ÷£¨È磺״̬¼Ä´æÆ ......
ÄÚÈÝ£ºIntroduction ºÍ Error Reporting
1. glibc ËùʵÏÖÈ«²¿»ò²¿·Ö¹æ·¶ÏµĹ¦ÄÜÓÐ
ISO C: The international standard for the C programming language.
POSIX: The ISO/IEC 9945 (aka IEEE 1003) standards for operating systems.
Berkeley Unix: BSD and SunOS.
SVID: The System V Interface Description.
X ......