fork() problem Post: 302107267

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Top Forums Programming fork() problem Post 302107267 by ddx08 on Thursday 15th of February 2007 06:15:00 PM

02-15-2007

Registered User

fork() problem

i'm just trying to make 2 process read from the same 1 line a time. For some reason only the child reads.

Code:

#include<stdio.h>
#include  <sys/types.h>
void getlinefromfilep(void);
void getlinefromfilec(void);
int see=0;
FILE * fileptr1;

//need globe variable to tell pro3 to stop
main()
{
char temp1[100];
char temp2[100];


pid_t  pid;

fileptr1 = fopen("sample.txt","rt");
        if( fileptr1 != NULL )
        {
                printf("opened\n");
		pid = fork();
			if (pid == 0)
			{
				while(see==0)
			        {
					printf("child started\n");
					fscanf(fileptr1,"%s",temp1);
					printf("%s",temp1);
					printf("\n");
					printf("child done\n");
					see=feof(fileptr1);
					printf("see = ");
					printf("%i",see);
					printf("\n");	      
                		} 
			}
			else
			{ 
				int i=0;
				char temp2[100];
				while(see==0)
	        		{
					printf("parnet started\n");
					fscanf(fileptr1,"%s",temp2);
					printf("%s",temp2);
					printf("\n");
					printf("parent done\n");
					see=feof(fileptr1);
					printf("see = ");
					printf("%i",see);
					printf("\n");      
                		}
			}

        }
        else
        {
                printf("not opened");
        }
	fclose(fileptr1);

}

ddx08

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LEARN ABOUT OSX

new_printf_comp

XPRINTF_COMP(3) 					   BSD Library Functions Manual 					   XPRINTF_COMP(3)

NAME

     free_printf_comp, new_printf_comp -- extensible printf compilation

SYNOPSIS

     #include <printf.h>

     void
     free_printf_comp(printf_comp_t pc);

     printf_comp_t
     new_printf_comp(printf_domain_t restrict domain, locale_t restrict loc, const char * restrict fmt);

DESCRIPTION

     To ameliorate some of the slowness caused by the extra overhead in extensible printf (see xprintf(5)), a compile/execute mechanism has been
     created.  The new_printf_comp() function compiles the given format string, along with a printf domain (see xprintf_domain(3)) and an extended
     locale (see xlocale(3)), and returns a printf_comp_t structure.  The domain may not be NULL, but the locale can be NULL, which means to use
     the current locale, either the per-thread locale if it was set, or else the global locale.  Because the printf_comp_t structure records the
     domain and locale, care should be taken if either of these are changed.

     Once a printf_comp_t structure is created, it can be passed to one of the extensible printf execution variants, described in xprintf_exec(3),
     along with the necessary arguments.  Creating the printf_comp_t structure needs to be done only once, but it can be passed to extensible
     printf execution variants any number of times.

     When the printf_comp_t structure is no longer needed, it should be passed to free_printf_comp() to release internal memory.

RETURN VALUES

     The new_printf_comp() function returns the new structure, or NULL on error (usually NULL domain or out of memory condition).

SEE ALSO

     xlocale(3), xprintf_domain(3), xprintf_exec(3), xprintf(5)

Darwin								   Aug 19, 2012 							    Darwin