| title | Global Variables | Microsoft Docs | |||||||||||||
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| ms.date | 11/04/2016 | |||||||||||||
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| ms.assetid | 01d1551c-2f0c-4f72-935c-6442caccf84f | |||||||||||||
| caps.latest.revision | 15 | |||||||||||||
| author | corob-msft | |||||||||||||
| ms.author | corob | |||||||||||||
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The Microsoft C run-time library provides the following global variables or macros. Several of these global variables or macros have been deprecated in favor of more-secure functional versions, which we recommend you use instead of the global variables.
| Variable | Description |
|---|---|
| __argc, __argv, __wargv | Contains the command-line arguments. |
| _daylight, _dstbias, _timezone, and _tzname | Deprecated. Instead, use _get_daylight, _get_dstbias, _get_timezone, and _get_tzname.Adjusts for local time; used in some date and time functions. |
| errno, _doserrno, _sys_errlist, and _sys_nerr | Deprecated. Instead, use _get_errno, _set_errno, _get_doserrno, _set_doserrno, perror and strerror.Stores error codes and related information. |
| _environ, _wenviron | Deprecated. Instead, use getenv_s, _wgetenv_s, _dupenv_s, _wdupenv_s, _putenv_s, and _wputenv_s.Pointers to arrays of pointers to the process environment strings; initialized at startup. |
| _fmode | Deprecated. Instead, use _get_fmode or _set_fmode.Sets default file-translation mode. |
| _iob | Array of I/O control structures for the console, files, and devices. |
| _pctype, _pwctype, _wctype, _mbctype, _mbcasemap | Contains information used by the character-classification functions. |
| _pgmptr, _wpgmptr | Deprecated. Instead, use _get_pgmptr or _get_wpgmptr.Initialized at program startup to the fully-qualified or relative path of the program, the full program name, or the program name without its file name extension, depending on how the program was invoked. |
C Run-Time Library Reference
Global Constants
__argc, __argv, __wargv
_get_daylight
_get_dstbias
_get_timezone
_get_tzname
perror
strerror
_get_doserrno
_set_doserrno
_get_errno
_set_errno
_dupenv_s, _wdupenv_s
getenv, _wgetenv
getenv_s, _wgetenv_s
_putenv, _wputenv
_putenv_s, _wputenv_s
_get_fmode
_set_fmode