/***
*stdenvp.c - standard _setenvp routine
*
* Copyright (c) 1989-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
* This module is called by the C start-up routine to set up "_environ".
* Its sets up an array of pointers to strings in the environment.
* The global symbol "_environ" is set to point to this array.
*
*Revision History:
* 11-07-84 GFW initial version
* 01-08-86 SKS Modified for OS/2
* 05-21-86 SKS Call _stdalloc to get memory for strings
* 09-04-86 SKS Added check to skip the "*C_FILE_INFO" string
* 10-21-86 SKS Improved check for "*C_FILE_INFO"/"_C_FILE_INFO"
* 02-19-88 SKS Handle case where environment starts with a single null
* 05-10-88 JCR Modified code to accept far pointer from _stdalloc
* 06-01-88 PHG Merged DLL and normal versions
* 07-12-88 JCR Largely re-written: (1) split mem allocation into two
* seperate malloc() calls to help simplify putenv(),
* (2) stdalloc() no longer robs from stack, (3) cProc/cEnd
* sequence, (4) misc cleanup
* 09-20-88 WAJ Initial 386 version
* 12-13-88 JCR Use rterr.inc parameters for runtime errors
* 04-09-90 GJF Added #include <cruntime.h>. Made the calling type
* _CALLTYPE1. Also, fixed the copyright and cleaned up
* up the formatting a bit.
* 06-05-90 GJF Changed error message interface.
* 10-08-90 GJF New-style function declarator.
* 10-31-90 GJF Fixed statement appending the final NULL (Stevewo
* found the bug).
* 12-11-90 SRW Changed to include <oscalls.h> and setup _environ
* correctly for Win32
* 01-21-91 GJF ANSI naming.
* 02-07-91 SRW Change _WIN32_ specific code to allocate static copy
* 02-18-91 SRW Change _WIN32_ specific code to allocate copy of
* variable strings as well [_WIN32_]
* 07-25-91 GJF Changed strupr to _strupr.
* 03-31-92 DJM POSIX support.
* 04-20-92 GJF Removed conversion to upper-case code for Win32.
* 04-06-93 SKS Replace _CRTAPI* with __cdecl
* 11-24-93 CFW Rip out Cruiser and filter out "=c:\foo" type.
* 11-29-93 CFW Remove unused POSIX stuff, wide char enable.
* 12-07-93 CFW Change _TCHAR to _TSCHAR.
* 01-10-95 CFW Debug CRT allocs.
* 04-07-95 CFW Free environment block on demand.
* 07-03-95 GJF Always free environment block.
* 02-20-96 SKS Set _aenvptr/_wenvptr to NULL after freeing what it
* points to (a copy of environment strings).
* 06-30-97 GJF Added explicit, conditional init. of the mbctype table.
* Set __env_initialized flag. Also detab-ed.
* 01-04-99 GJF Changes for 64-bit size_t.
* 03-05-01 PML Don't AV if _aenvptr is NULL (vs7#174755).
* 03-27-01 PML Return error instead of calling amsg_exit (vs7#231220)
*
*******************************************************************************/
#include <cruntime.h>
#include <string.h>
#include <stdlib.h>
#include <internal.h>
#include <rterr.h>
#include <oscalls.h>
#include <tchar.h>
#include <dbgint.h>
#ifndef CRTDLL
#ifdef _MBCS
/*
* Flag to ensure multibyte ctype table is only initialized once
*/
extern int __mbctype_initialized;
#endif
/*
* Flag checked by getenv() and _putenv() to determine if the environment has
* been initialized.
*/
extern int __env_initialized;
#endif
/***
*_setenvp - set up "envp" for C programs
*
*Purpose:
* Reads the environment and build the envp array for C programs.
*
*Entry:
* The environment strings occur at _aenvptr.
* The list of environment strings is terminated by an extra null
* byte. Thus two null bytes in a row indicate the end of the
* last environment string and the end of the environment, resp.
*
*Exit:
* "environ" points to a null-terminated list of pointers to ASCIZ
* strings, each of which is of the form "VAR=VALUE". The strings
* are copied from the environment area. This array of pointers will
* be malloc'ed. The block pointed to by _aenvptr is deallocated.
*
*Uses:
* Allocates space on the heap for the environment pointers.
*
*Exceptions:
* If space cannot be allocated, program is terminated.
*
*******************************************************************************/
#ifdef WPRFLAG
int __cdecl _wsetenvp (
#else
int __cdecl _setenvp (
#endif
void
)
{
_TSCHAR *p;
_TSCHAR **env; /* _environ ptr traversal pointer */
int numstrings; /* number of environment strings */
int cchars;
#if !defined(CRTDLL) && defined(_MBCS)
/* If necessary, initialize the multibyte ctype table. */
if ( __mbctype_initialized == 0 )
__initmbctable();
#endif
numstrings = 0;
#ifdef WPRFLAG
p = _wenvptr;
#else
p = _aenvptr;
#endif
/*
* We called __crtGetEnvironmentStrings[AW] just before this,
* so if _[aw]envptr is NULL, we failed to get the environment.
* Return an error.
*/
if (p == NULL)
return -1;
/*
* NOTE: starting with single null indicates no environ.
* Count the number of strings. Skip drive letter settings
* ("=C:=C:\foo" type) by skipping all environment variables
* that begin with '=' character.
*/
while (*p != _T('\0')) {
/* don't count "=..." type */
if (*p != _T('='))
++numstrings;
p += _tcslen(p) + 1;
}
/* need pointer for each string, plus one null ptr at end */
if ( (_tenviron = env = (_TSCHAR **)
_malloc_crt((numstrings+1) * sizeof(_TSCHAR *))) == NULL )
return -1;
/* copy strings to malloc'd memory and save pointers in _environ */
#ifdef WPRFLAG
for ( p = _wenvptr ; *p != L'\0' ; p += cchars )
#else
for ( p = _aenvptr ; *p != '\0' ; p += cchars )
#endif
{
cchars = (int)_tcslen(p) + 1;
/* don't copy "=..." type */
if (*p != _T('=')) {
if ( (*env = (_TSCHAR *)_malloc_crt(cchars * sizeof(_TSCHAR)))
== NULL )
{
_free_crt(_tenviron);
_tenviron = NULL;
return -1;
}
_tcscpy(*env, p);
env++;
}
}
#ifdef WPRFLAG
_free_crt(_wenvptr);
_wenvptr = NULL;
#else
_free_crt(_aenvptr);
_aenvptr = NULL;
#endif
/* and a final NULL pointer */
*env = NULL;
#ifndef CRTDLL
/*
* Set flag for getenv() and _putenv() to know the environment
* has been set up.
*/
__env_initialized = 1;
#endif
return 0;
}