_SC_PAGESIZE

C:\cygwin\usr\include\sys\unistd.h

/*
 *  sysconf values per IEEE Std 1003.1, 2008 Edition
 */

#define _SC_ARG_MAX                       0
#define _SC_CHILD_MAX                     1
#define _SC_CLK_TCK                       2
#define _SC_NGROUPS_MAX                   3
#define _SC_OPEN_MAX                      4
#define _SC_JOB_CONTROL                   5
#define _SC_SAVED_IDS                     6
#define _SC_VERSION                       7
#define _SC_PAGESIZE                      8
#define _SC_PAGE_SIZE                     _SC_PAGESIZE