Global Variables

The Microsoft run-time library provides the following global variables. These global variables have been deprecated for the more secure functional versions, which should be used in place of the global variable (except _pgmptr and _wpgmptr).

Variable	Description
_acmdln, _tcmdln, _wcmdln	Contains the command line.
_amblksiz	Controls memory heap granularity
_daylight, _dstbias, _timezone, and _tzname	Adjust for local time; used in some date and time functions
errno, _doserrno, _sys_errlist, and _sys_nerr	Store error codes and related information
_environ, _wenviron	Pointers to arrays of pointers to strings that constitute process environment
_fileinfo	Specifies whether information regarding open files of a process is passed to new processes
_fmode	Sets default file-translation mode
_iob	The array of stdio control structures.
_pctype, _pwctype, _wctype, _mbctype, _mbcasemap	Contain information used by the character classification functions.
_pgmptr, _wpgmptr	Initialized at program startup to value such as program name, filename, relative path, or full path

See Also

Reference

Global Constants

_get_amblksiz

_set_amblksiz

_get_daylight

_get_dstbias

_get_timezone

_get_tzname

perror

strerror

_get_doserrno

_set_doserrno

_get_errno

_set_errno

getenv, _wgetenv

getenv_s, _wgetenv_s

_putenv, _wputenv

_putenv_s, _wputenv_s

_get_fmode

_set_fmode

Other Resources

Run-Time Library Reference