lib/openmax.c
#include "apue.h" #include <errno.h> #include <limits.h> #ifdef OPEN_MAX static long openmax = OPEN_MAX; #else static long openmax = 0; #endif /* * If OPEN_MAX is indeterminate, we‘re not * guaranteed that this is adequate. */ #define OPEN_MAX_GUESS 256 long open_max(void) { if (openmax == 0) { /* first time through */ errno = 0; if ((openmax = sysconf(_SC_OPEN_MAX)) < 0) { if (errno == 0) openmax = OPEN_MAX_GUESS; /* it‘s indeterminate */ else err_sys("sysconf error for _SC_OPEN_MAX"); } } return(openmax); }
原文地址:http://www.cnblogs.com/paullam/p/3849926.html