linux C forkº¯Êý
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1.1.1. forkº¯Êý¸Éʲô£¿
#include <sys/types.h>
#include <unistd.h>
pid_t fork(void);
‘fork()’º¯ÊýÓÃÓÚ´ÓÒÑ´æÔÚ½ø³ÌÖд´½¨Ò»¸öнø³Ì¡£Ð½ø³Ì³ÆÎª×Ó½ø³Ì£¬¶øÔ½ø³Ì³ÆÎª¸¸½ø³Ì¡£Äã¿ÉÒÔͨ¹ý¼ì²é‘fork()’º¯ÊýµÄ·µ»ØÖµÖªµÀÄĸöÊǸ¸½ø³Ì£¬ÄĸöÊÇ×Ó½ø³Ì¡£¸¸½ø³ÌµÃµ½µÄ·µ»ØÖµÊÇ×Ó½ø³ÌµÄ½ø³ÌºÅ£¬¶ø×Ó½ø³ÌÔò·µ»Ø0¡£ÒÔÏÂÕâ¸ö·¶Àý³ÌÐò˵Ã÷ËüµÄ»ù±¾¹¦ÄÜ£º
pid_t pid;
switch (pid = fork())
{
case -1:
/* ÕâÀïpidΪ-1£¬forkº¯Êýʧ°Ü */
/* һЩ¿ÉÄܵÄÔÒòÊÇ */
/* ½ø³ÌÊý»òÐéÄâÄÚ´æÓþ¡ */
perror("The fork failed!");
break;
case 0:
/* pidΪ0£¬×Ó½ø³Ì */
/* ÕâÀÎÒÃÇÊǺ¢×Ó£¬Òª×öʲô£¿ */
/* ... */
/* µ«ÊÇ×öÍêºó, ÎÒÃÇÐèÒª×öÀàËÆÏÂÃæ£º */
_exit(0);
default:
/* pid´óÓÚ0£¬Îª¸¸½ø³ÌµÃµ½µÄ×Ó½ø³ÌºÅ */
printf("Child's pid is %d\n",pid);
}
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#include <math.h>
int main(void)
{
int number = -1234;
printf("number: %d absolute value: %d\n", number, abs(number));
return 0;
}
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