fork04.c

cygwin, 著名的在win32下模拟unix操作系统的东东

/*
 * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Further, this software is distributed without any warranty that it is
 * free of the rightful claim of any third person regarding infringement
 * or the like.  Any license provided herein, whether implied or
 * otherwise, applies only to this software file.  Patent licenses, if
 * any, provided herein do not apply to combinations of this program with
 * other software, or any other product whatsoever.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write the Free Software Foundation, Inc., 59
 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
 *
 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
 * Mountain View, CA  94043, or:
 *
 * http://www.sgi.com
 *
 * For further information regarding this notice, see:
 *
 * http://oss.sgi.com/projects/GenInfo/NoticeExplan/
 *
 */
/* $Id: fork04.c,v 1.2 2000/09/06 14:21:53 duda Exp $ */
/**********************************************************
 * 
 *    OS Test - Silicon Graphics, Inc.
 * 
 *    TEST IDENTIFIER	: fork04
 * 
 *    TEST TITLE	: Child inheritance of Environment Variables after fork()
 * 
 *    PARENT DOCUMENT	: frktds01
 * 
 *    TEST CASE TOTAL	: 3
 * 
 *    WALL CLOCK TIME	: 1
 * 
 *    CPU TYPES		: ALL
 * 
 *    AUTHOR		: Kathy Olmsted
 * 
 *    CO-PILOT		: Steve Shaw
 * 
 *    DATE STARTED	: 06/17/92
 * 
 *    INITIAL RELEASE	: UNICOS 7.0
 * 
 *    TEST CASES
 *       Test these environment variables correctly inherited by child:
 *       1. TERM 
 *       2. NoTSetzWq
 *       3. TESTPROG 
 *	
 *    INPUT SPECIFICATIONS
 * 	The standard options for system call tests are accepted.
 *	(See the parse_opts(3) man page).
 * 
 *    DURATION
 * 	Terminates - with frequency and infinite modes.
 * 
 *    SIGNALS
 * 	Uses SIGUSR1 to pause before test if option set.
 * 	(See the parse_opts(3) man page).
 *
 *    ENVIRONMENTAL NEEDS
 *      No run-time environmental needs.
 * 
 *    DETAILED DESCRIPTION
 *
 * 	Setup:
 * 	  Setup signal handling.
 *        Make and change to a temporary directory.
 *	  Pause for SIGUSR1 if option specified.
 *        Add TESTPROG variable to the environment
 * 
 * 	Test:
 *	 Loop if the proper options are given.
 *	 fork()
 *	 Check return code, if system call failed (return=-1)
 *		Log the errno
 *	   CHILD:
 *              open a temp file
 *		Determine environment values and write to file
 *		close file containing test values.
 *		exit.
 *	    PARENT:
 *		Wait for child to exit.
 *              Verify exit status
 *		Open file containing test values.
 *		For each test case:
 *			Read the value from the file.
 *			Determine and report PASS/FAIL result.
 *
 * 	Cleanup:
 * 	  Print errno log and/or timing stats if options given
 *        Remove the temporary directory and exit. 
 * 
 * 
 *#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#**/
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <sys/param.h>
#include <signal.h>		/*Includes signal information. */
#include <errno.h>
#include "test.h"    
#include "usctest.h"

char *TCID="fork04";		/* Test program identifier.    */
extern int Tst_count;		/* Test Case counter for tst_* routines */



#define	KIDEXIT	42		/* Known value for child exit status */
#define MAX_LINE_LENGTH 256
#define OUTPUT_FILE  "env.out"
#define ENV_NOT_SET  "getenv() does not find variable set"

/* list of environment variables to test */
char *environ_list[] = {"TERM","NoTSetzWq","TESTPROG"};
#define NUMBER_OF_ENVIRON sizeof(environ_list)/sizeof(char *)
int TST_TOTAL=NUMBER_OF_ENVIRON;		/* Total number of test cases. */

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

  /* remove the temporary directory and exit with 
       return code appropriate for results */
  tst_rmdir();
  tst_exit();

}	/* End cleanup() */

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

  /* make and change to a temporary directory */
  tst_tmpdir();

  /* add a variable to the environment */
  putenv("TESTPROG=FRKTCS04");

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

}	/* End setup() */


/***************************************************************
 * child_environment - the child side of the environment tests
 *        determine values for the variables and write to a file
 ***************************************************************/
void child_environment()
{
  
  int fildes;
  int index;
  char msg[MAX_LINE_LENGTH];
  char *var;
  
  fildes = creat(OUTPUT_FILE,0700);

  
  for (index=0;index<NUMBER_OF_ENVIRON;index++) {
      memset(msg, 0, MAX_LINE_LENGTH);

      if ( (var=getenv(environ_list[index])) == NULL ) 
          (void)sprintf(msg,"%s:%s",environ_list[index], ENV_NOT_SET);
      else
          (void)sprintf(msg,"%s:%s",environ_list[index], var);

      write(fildes,msg,sizeof(msg));   /* includes extra null chars */
  }
  
  close(fildes);

}

/***********************************************************************
 *
 * Compare parent env string to child's string.
 * Each string is in the format:  <env var>:<value>
 *
 ***********************************************************************/
int
cmp_env_strings(char *pstring, char *cstring)
{
   char *penv, *cenv, *pvalue, *cvalue;

   /*
    * Break pstring into env and value
    */
   penv=pstring;
   if ( (pvalue=strchr(pstring, ':'))  == NULL )  {
       tst_resm(TBROK, 
           "internal error - parent's env string not in correct format:'%s'",
	   pstring);
       return -1;
   } else {
       *pvalue='\0';
       pvalue++;
       if ( *pvalue == '\0' ) {
	   tst_resm(TBROK, "internal error - missing parent's env value");
	   return -1;
       }
   }

   /*
    * Break cstring into env and value
    */
   cenv=cstring;
   if ( (cvalue=strchr(cstring, ':'))  == NULL )  {
       tst_resm(TBROK, 
           "internal error - parent's env string not in correct format:'%s'",
	   cstring);
       return -1;
   } else {
       *cvalue='\0';
       cvalue++;
       if ( *cvalue == '\0' ) {
	   tst_resm(TBROK, "internal error - missing child's env value");
	   return -1;
       }
   }

   if ( strcmp(penv, cenv) != 0 ) {
       tst_resm(TBROK, "internal error - parent(%s) != child (%s) env",
	penv, cenv);
       return -1;
   }

   if ( strcmp(pvalue, cvalue) != 0 ) {
      tst_resm(TFAIL, "Env var %s changed after fork(), parent's %s, child's %s",
	penv, pvalue, cvalue);
   } else {
      tst_resm(TPASS, "Env var %s unchanged after fork(): %s",
	penv, cvalue);
   }
   return 0;
   
}

/***************************************************************
 * parent_environment - the parent side of the environment tests
 *        determine values for the variables
 *        read the values determined by the child
 *        compare values 
 ***************************************************************/
void parent_environment()
{
  
  int fildes;
  char tmp_line[MAX_LINE_LENGTH];
  char parent_value[MAX_LINE_LENGTH];
  int index;
  int ret;
  char *var;
  
  if ((fildes = open(OUTPUT_FILE,O_RDWR)) == -1) {
    tst_brkm(TBROK, cleanup,
		 "fork() test. Parent open of temporary file failed. errno %d (%s)\n",
		 errno, strerror(errno));
  }
  for (index=0;index<NUMBER_OF_ENVIRON;index++) 
    {
      if ((ret=read(fildes,tmp_line,MAX_LINE_LENGTH)) == 0) {
	tst_resm(TBROK,"fork() test. parent_environment: failed to read from file with %d (%s)",
		errno,strerror(errno));
      }
      else {

	if ( (var=getenv(environ_list[index])) == NULL ) 
            sprintf(parent_value,"%s:%s", environ_list[index], ENV_NOT_SET);
	else
            sprintf(parent_value,"%s:%s", environ_list[index], var);

        cmp_env_strings(parent_value, tmp_line);
	
      }
    }
  close(fildes);

}

/***************************************************************
 * main() - performs tests
 *	
 ***************************************************************/

int
main(int ac, char **av)
{
    int lc;		/* loop counter */
    const char *msg;		/* message returned from parse_opts */
    int kid_status;     /* status returned from child */
    int wait_status;    /* status of wait system call in parent */
    int fails;          /* indicates whether to continue with tests */

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

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

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

	/* reset Tst_count and fail indicator in case we are looping. */
	Tst_count=0;
	fails = 0;

	/* make the call to fork */
	TEST(fork());
	
	/* check return code */
	if ( TEST_RETURN == -1 ) {
	  /* fork failed */
	  if ( STD_FUNCTIONAL_TEST ) {
	    tst_brkm(TFAIL, cleanup, "fork() failed with %d (%s)",
		     TEST_ERRNO, strerror(TEST_ERRNO));
	  }
	}
	else if (TEST_RETURN == 0) {
	  /* child */
	  if ( STD_FUNCTIONAL_TEST ) {
	    /* determine environment variables */
	    child_environment();
	  }
	  /* exit with known value */
	  exit(KIDEXIT);
	} else {
	  /* parent of successful fork */
	  /* wait for the child to complete */
	  wait_status = wait(&kid_status);
	  if ( STD_FUNCTIONAL_TEST ) {
	    /* validate the child exit status */
	    if (wait_status == TEST_RETURN) {
	      if (kid_status != KIDEXIT << 8) {
		tst_brkm(TBROK, cleanup,
			     "fork(): Incorrect child status returned on wait(): %d", 
			     kid_status);
		fails++;
	      }
	    }
	    else {
	      tst_brkm(TBROK, cleanup,
		       "fork(): wait() for child status failed with %d errno: %d : %s", 
		       wait_status,errno,strerror(errno));
	      fails++;
	    }
	  
	    if (fails == 0 ) {
	      /* verification tests */
	      parent_environment();
	    }
	  }
	}

      }	/* End for TEST_LOOPING */

    /***************************************************************
     * cleanup and exit
     ***************************************************************/
    cleanup();

    return 0;
}	/* End main */