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/***
*mktemp.c - create a unique file name
*
* Copyright (c) 1985-1993, Microsoft Corporation. All rights reserved.
*
*Purpose:
* defines _mktemp() - create a unique file name
*
*Revision History:
* 06-02-86 JMB eliminated unneccesary routine exits
* 05-26-87 JCR fixed bug where mktemp was incorrectly modifying
* the errno value.
* 12-11-87 JCR Added "_LOAD_DS" to declaration
* 07-11-88 JCR Optimized REG allocation
* 03-12-90 GJF Replaced _LOAD_DS with _CALLTYPE1, added #include
* <cruntime.h>, removed #include <register.h> and
* fixed the copyright. Also, cleaned up the formatting
* a bit.
* 04-04-90 GJF Added #include <process.h> and #include <io.h>. Removed
* #include <sizeptr.h>.
* 07-23-90 SBM Replaced <assertm.h> by <assert.h>
* 08-13-90 SBM Compiles cleanly with -W3
* 09-28-90 GJF New-style function declarator.
* 01-16-91 GJF ANSI naming.
* 11-30-92 KRS Ported _MBCS code from 16-bit tree.
* 06-18-93 KRS MBCS-only bug fix ported from 16-bit tree.
* 08-03-93 KRS Call _ismbstrail instead of isdbcscode.
*
*******************************************************************************/
#include <cruntime.h>
#include <stdio.h>
#include <io.h>
#include <process.h>
#include <errno.h>
#include <assert.h>
#include <stddef.h>
#ifdef _MBCS
#include <mbctype.h>
#include <mbdata.h>
#endif
/***
*char *_mktemp(template) - create a unique file name
*
*Purpose:
* given a template of the form "fnamXXXXXX", insert number on end
* of template, insert unique letter if needed until unique filename
* found or run out of letters
#ifdef OS2_COMMENT
* Note: this version can be used for both DOS 3 and OS/2
#endif
*
*Entry:
* char *template - template of form "fnamXXXXXX"
*
*Exit:
* return pointer to modifed template
* returns NULL if template malformed or no more unique names
*
*Exceptions:
*
*******************************************************************************/
char * _CALLTYPE1 _mktemp (
char *template
)
{
REG1 char *string = template;
REG3 unsigned number;
int letter = 'a';
REG2 int xcount = 0;
int olderrno;
assert(template != NULL);
assert(*template != '\0');
number = _getpid();
while (*string)
string++;
#ifdef _MBCS
while ((--string>=template) && (!_ismbstrail(template,string))
&& (*string == 'X'))
#else
while (*--string == 'X')
#endif
{
xcount++;
*string = (char)((number % 10) + '0');
number /= 10;
}
if (*++string == '\0' || xcount != 6 )
return(NULL);
olderrno = errno; /* save current errno */
errno = 0; /* make sure errno isn't EACCESS */
while ((_access(template,0) == 0) || (errno == EACCES))
/* while file exists */
{
errno = 0;
if (letter == 'z'+1) {
errno = olderrno;
return(NULL);
}
*string = (char)letter++;
}
errno = olderrno;
return(template);
}
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