Subversion Repositories planix.SVN

/*

 * pANS stdio -- tmpfile

 *

 * Bug: contains a critical section.  Two executions by the same

 * user could interleave as follows, both yielding the same file:

 *	access fails

 *			access fails

 *	fopen succeeds

 *			fopen succeeds

 *	unlink succeeds

 *			unlink fails

 * As I read the pANS, this can't reasonably use tmpnam to generate

 * the name, so that code is duplicated.

 */

#include "iolib.h"

static char tmpsmade[FOPEN_MAX][L_tmpnam+1];

static int ntmps = 0;

static void rmtmps(void);

FILE *tmpfile(void){

	FILE *f;

	static char name[]="/tmp/tf0000000000000";

	char *p;

	while(access(name, 0)==0){

		p=name+7;

		while(*p=='9') *p++='0';

		if(*p=='\0') return NULL;

		++*p;

	}

	f=fopen(name, "wb+");

	if(f && ntmps<FOPEN_MAX){

		if(ntmps==0)

			atexit(rmtmps);

		strcpy(tmpsmade[ntmps++], name);

	}

	return f;

}

static void

rmtmps(void)

{

	int i;

	for(i=0; i<ntmps; i++)

		remove(tmpsmade[i]);

}