read04.c

cygwin, 著名的在win32下模拟unix操作系统的东东

/*
 *
 *   Copyright (c) International Business Machines  Corp., 2001
 *
 *   This program is free software;  you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program;  if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

/*
 * NAME
 *	read01.c
 *
 * DESCRIPTION
 *	Testcase to check if read returns the number of bytes read correctly.
 *
 * ALGORITHM
 *	Create a file and write some bytes out to it.
 *	Attempt to read more than written.
 *	Check the return count, and the read buffer. The read buffer should be
 *	same as the write buffer.
 *
 * USAGE:  <for command-line>
 *  read01 [-c n] [-f] [-i n] [-I x] [-P x] [-t]
 *     where,  -c n : Run n copies concurrently.
 *             -f   : Turn off functionality Testing.
 *             -i n : Execute test n times.
 *             -I x : Execute test for x seconds.
 *             -P x : Pause for x seconds between iterations.
 *             -t   : Turn on syscall timing.
 *
 * HISTORY
 *	07/2001 Ported by Wayne Boyer
 *
 * RESTRICTIONS
 *	None
 */
#include <stdio.h>
#include <fcntl.h>
#include <errno.h>
#include "test.h"
#include "usctest.h"

void cleanup(void);
void setup(void);

char *TCID = "read01";
int TST_TOTAL = 1;
extern int Tst_count;

#define TST_SIZE	26		/* could also do strlen(palfa) */
char    fname[255];
char    palfa[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" ;
int fild;

main(int ac, char **av)
{
	int lc;			/* loop counter */
	const char *msg;	/* message returned from parse_opts */

	int n;
	int rfild;
	char prbuf[BUFSIZ];

	/*
	 * parse standard options
	 */
	if ((msg = parse_opts(ac, av, (option_t *)NULL, NULL)) != (char *)NULL){
		tst_brkm(TBROK, tst_exit, "OPTION PARSING ERROR - %s", msg);
		/*NOTREACHED*/
	}

	setup();		/* global setup for test */

	/* check looping state if -i option given */
	for (lc = 0; TEST_LOOPING(lc); lc++) {

		Tst_count = 0;		/* reset Tst_count while looping */

		if ((rfild = open(fname, O_RDONLY)) == -1) {
			tst_brkm(TBROK, cleanup, "can't open for reading");
			/*NOTREACHED*/
		}
		TEST(read(rfild, prbuf, BUFSIZ));

		if (TEST_RETURN == -1) {
			tst_resm(TFAIL, "call failed unexpectedly");
			continue;
		}

		if (STD_FUNCTIONAL_TEST) {
			if (TEST_RETURN != TST_SIZE) {
				tst_resm(TFAIL, "Bad read count - got %d - "
					 "expected %d", TEST_RETURN, TST_SIZE);
				continue;
			}
			if (memcmp(palfa, prbuf, TST_SIZE) != 0) {
				tst_resm(TFAIL, "read buffer not equal "
					 "to write buffer");
				continue;
			}
			tst_resm(TPASS, "functionality of read() is correct");
		} else {
			tst_resm(TPASS, "call succeeded");
		}
		if (close(rfild) == -1) {
			tst_brkm(TBROK, cleanup, "close() failed");
			/*NOTREACHED*/
		}
	}
	cleanup();
	/*NOTREACHED*/
}

/*
 * setup() - performs all ONE TIME setup for this test 
 */
void
setup(void)
{
	/* capture signals */
	tst_sig(NOFORK, DEF_HANDLER, cleanup);

	umask(0);

	/* Pause if that option was specified */
	TEST_PAUSE;

	/* make a temp directory and cd to it */
	tst_tmpdir();

	sprintf(fname,"tfile_%d",getpid());

	if ((fild = creat(fname, 0777)) == -1) {
		tst_brkm(TBROK, cleanup, "creat(%s, 0777) Failed, errno = %d"
			 " : %s", fname, errno, strerror(errno));
		/*NOTREACHED*/
	}
	if (write(fild, palfa, TST_SIZE) != TST_SIZE) {
		tst_brkm(TBROK, cleanup, "can't write to Xread");
		/*NOTREACHED*/
	}
        close (fild);
}

/*
 * cleanup() - performs all ONE TIME cleanup for this test at completion or
 *	       premature exit.
 */
void
cleanup(void)
{
	/*
	 * print timing stats if that option was specified.
	 * print errno log if that option was specified.
	 */
	TEST_CLEANUP;

	/* Remove tmp dir and all files in it */
	unlink(fname);
	tst_rmdir();

	/* exit with return code appropriate for results */
	tst_exit();
}