58 lines
1.3 KiB
C
58 lines
1.3 KiB
C
/*
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* This file is part of the UCB release of Plan 9. It is subject to the license
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* terms in the LICENSE file found in the top-level directory of this
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* distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
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* part of the UCB release of Plan 9, including this file, may be copied,
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* modified, propagated, or distributed except according to the terms contained
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* in the LICENSE file.
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*/
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/*
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* pANS stdio -- tmpfile
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*
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* Bug: contains a critical section. Two executions by the same
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* user could interleave as follows, both yielding the same file:
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* access fails
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* access fails
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* fopen succeeds
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* fopen succeeds
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* unlink succeeds
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* unlink fails
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* As I read the pANS, this can't reasonably use tmpnam to generate
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* the name, so that code is duplicated.
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*/
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#include "iolib.h"
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static char tmpsmade[FOPEN_MAX][L_tmpnam+1];
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static int ntmps = 0;
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static void rmtmps(void);
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FILE *tmpfile(void){
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FILE *f;
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static char name[]="/tmp/tf0000000000000";
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char *p;
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while(access(name, AEXIST)==0){
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p=name+7;
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while(*p=='9') *p++='0';
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if(*p=='\0') return NULL;
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++*p;
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}
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f=fopen(name, "wb+");
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if(f && ntmps<FOPEN_MAX){
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if(ntmps==0)
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atexit(rmtmps);
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strcpy(tmpsmade[ntmps++], name);
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}
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return f;
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}
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static void
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rmtmps(void)
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{
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int i;
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for(i=0; i<ntmps; i++)
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remove(tmpsmade[i]);
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}
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