get_avphys_pages(3)

1get_phys_pages(3)          Library Functions Manual          get_phys_pages(3)
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NAME

6       get_phys_pages,  get_avphys_pages  -  get  total and available physical
7       page counts
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LIBRARY

10       Standard C library (libc, -lc)
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SYNOPSIS

13       #include <sys/sysinfo.h>
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15       long get_phys_pages(void);
16       long get_avphys_pages(void);
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DESCRIPTION

19       The function get_phys_pages() returns  the  total  number  of  physical
20       pages of memory available on the system.
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22       The  function get_avphys_pages() returns the number of currently avail‐
23       able physical pages of memory on the system.
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RETURN VALUE

26       On success, these functions return a nonnegative value as given in  DE‐
27       SCRIPTION.   On  failure,  they return -1 and set errno to indicate the
28       error.
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ERRORS

31       ENOSYS The system could not provide the required information  (possibly
32              because the /proc filesystem was not mounted).
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STANDARDS

35       GNU.
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HISTORY

38       Before glibc 2.23, these functions obtained the required information by
39       scanning the MemTotal and MemFree fields of /proc/meminfo.  Since glibc
40       2.23,  these  functions obtain the required information by calling sys‐
41       info(2).
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NOTES

44       The following sysconf(3) calls provide a portable  means  of  obtaining
45       the same information as the functions described on this page.
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47           total_pages = sysconf(_SC_PHYS_PAGES);    /* total pages */
48           avl_pages = sysconf(_SC_AVPHYS_PAGES);    /* available pages */
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EXAMPLES

51       The following example shows how get_phys_pages() and get_avphys_pages()
52       can be used.
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54       #include <stdio.h>
55       #include <stdlib.h>
56       #include <sys/sysinfo.h>
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58       int
59       main(void)
60       {
61           printf("This system has %ld pages of physical memory and "
62                   "%ld pages of physical memory available.\n",
63                   get_phys_pages(), get_avphys_pages());
64           exit(EXIT_SUCCESS);
65       }
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