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setbuf

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setbuf, setbuffer, setlinebuf, setvbuf - ¥¹¥È¥ê¡¼¥à¤Î¥Ð¥Ã¥Õ¥¡¥ê¥ó¥°¤ÎÁàºî

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#include <stdio.h>

void setbuf(FILE *stream, char *buf);
void setbuffer(FILE *stream, char *buf, size_t size);
void setlinebuf(FILE *stream);
int setvbuf(FILE *stream, char *buf, int mode , size_t size);

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setvbuf() ´Ø¿ô¤Ï¡¢¥ª¡¼¥×¥ó¤·¤Æ¤¤¤ëǤ°Õ¤Î¥¹¥È¥ê¡¼¥à¤ËÂФ·¤Æ¥Ð¥Ã¥Õ¥¡¤òÊѹ¹¤Ç¤­¤ë¡£ ¥Ñ¥é¥á¡¼¥¿ mode ¤Ï¡¢¼¡¤Î 3 ¤Ä¤Î¥Þ¥¯¥í¤Î¤¦¤Á¤¤¤º¤ì¤«¤Ç¤¢¤ë:

_IONBF

unbuffered

_IOLBF

line buffered

_IOFBF

fully buffered

unbuffered ¤Î¥Õ¥¡¥¤¥ë¤ò½ü¤­¡¢ buf °ú¿ô¤Ï size ¥Ð¥¤¥È°Ê¾å¤ÎÂ礭¤µ¤Î¥Ð¥Ã¥Õ¥¡¤ò»Ø¤·¤Æ¤¤¤Ê¤±¤ì¤Ð¤Ê¤é¤Ê¤¤¡£¤³¤Î¥Ð¥Ã¥Õ¥¡¤Ï¸½ºß¤Î ¥Ð¥Ã¥Õ¥¡¤ÎÂå¤ï¤ê¤ËÍѤ¤¤é¤ì¤ë¡£¤â¤·¡¢°ú¿ô buf ¤¬ NULL ¤Ê¤é¤Ð¡¢¥â¡¼¥É¤À¤±¤¬Êѹ¹¤µ¤ì¤ë¡£ ¿·¤·¤¤¥Ð¥Ã¥Õ¥¡¤Ï¼¡¤ËÆɤ߽ñ¤­¤·¤¿ºÝ¤Ë³ä¤êÅö¤Æ¤é¤ì¤ë¡£ setvbuf() ´Ø¿ô¤Ï¡¢¥¹¥È¥ê¡¼¥à¤ò¥ª¡¼¥×¥ó¤·¤¿¸å¡¢ ¤½¤Î¥¹¥È¥ê¡¼¥à¤ËÂФ·¤Æ²¿¤é¤«¤ÎÁàºî¤ò¤¹¤ëÁ°¤Ë¤Î¤ß»ÈÍѤǤ­¤ë¡£

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setvbuf(stream, buf, buf ? _IOFBF : _IONBF, BUFSIZ);

¤ÈÁ´¤¯Æ±Åù¤À¤·¡¢ setbuffer() ´Ø¿ô¤Ï¡¢¥Ð¥Ã¥Õ¥¡¥µ¥¤¥º¤¬¥Ç¥Õ¥©¥ë¥ÈÃÍ BUFSIZ ¤Ç¤Ï¤Ê¤¯°ú¿ô¤ÇÍ¿¤¨¤é¤ì¤ëÅÀ°Ê³°¤ÏƱ¤¸¤Ç¤¢¤ë¡£ setlinebuf() ´Ø¿ô¤Ï

setvbuf(stream, (char *) NULL, _IOLBF, 0);

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setvbuf() ´Ø¿ô¤Ï¡¢À®¸ù¤·¤¿¾ì¹ç 0 ¤òÊÖ¤¹¡£ ¼ºÇÔ¤·¤¿¾ì¹ç¤ÏǤ°Õ¤ÎÃͤòÊÖ¤¹¤³¤È¤¬¤¢¤êÆÀ¤ë¤¬¡¢ mode ¤¬ÉÔÀµ¤Ê¾ì¹ç¤Þ¤¿¤Ï¥ê¥¯¥¨¥¹¥È¤¬¾ò·ï¤òËþ¤¿¤µ¤Ê¤¤¾ì¹ç¤Ï¡¢0 °Ê³°¤òÊÖ¤¹¡£ setvbuf() ´Ø¿ô¤¬¼ºÇÔ¤·¤¿¾ì¹ç¤Ï errno ¤òÀßÄꤹ¤ë¤³¤È¤â¤¢¤ë¡£ ¤½¤Î¾¤Î´Ø¿ô¤ÎÊÖ¤êÃÍ¤Ï void ¤Ç¤¢¤ë¡£

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setbuf() ´Ø¿ô¤ª¤è¤Ó setvbuf() ´Ø¿ô¤Ï C89 ¤È C99 ¤Ë½àµò¤·¤Æ¤¤¤ë¡£

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setbuffer() ´Ø¿ô¤ª¤è¤Ó setlinebuf() ´Ø¿ô¤Ï 4.2BSD ¤è¤êÁ°¤Î BSD ¤È¤Ï¸ß´¹À­¤¬¤Ê¤¤¡£¤Þ¤¿ Linux ¤Ç¤â(¸Å¤¤¥Ð¡¼¥¸¥ç¥ó ¤Ç¤Ï)ÍøÍѤǤ­¤Ê¤¤¤«¤â¤·¤ì¤Ê¤¤¡£4.2BSD ¤ª¤è¤Ó 4.3BSD ¤Î¥·¥¹¥Æ¥à¤Ç¤Ï setbuf() ¤Ïɬ¤ºÄɲäΥХåե¡¡¼¤Î¥µ¥¤¥º¤ò»ÈÍѤ¹¤ë¤Î¤Ç¡¢¤³¤ì¤â»È¤¦¤Ù¤­¤Ç¤Ê¤¤¡£ stream ¤òÊĤ¸¤ë»þ (¥×¥í¥°¥é¥à¤ò½ªÎ»¤¹¤ëºÝ¤Ë¤â¤³¤ì¤Ïµ¯¤­¤ë) ¤Ë¤Ï¡¢ buf ¤È ¤½¤Î»Ø¤·¼¨¤¹¶õ´Ö¤È¤¬Â¸ºß¤·¤Æ¤¤¤ë¤³¤È¤òÊݾڤ·¤Ê¤±¤ì¤Ð¤Ê¤é¤Ê¤¤¡£ Î㤨¤Ð¡¢¼¡¤Î¤è¤¦¤Ê»È¤¤Êý¤Ïµö¤µ¤ì¤Ê¤¤:

#include <stdio.h>



int

main(void)

{

    char buf[BUFSIZ];

    setbuf(stdin, buf);

    printf("Hello, world!\n");

    return 0;

}

´ØÏ¢¹àÌÜ

fclose(3), fflush(3), fopen(3), fread(3), malloc(3), printf(3), puts(3)