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Full Discussion: pipe program in C
Top Forums Programming pipe program in C Post 302473549 by beandj on Sunday 21st of November 2010 09:49:27 AM
Old 11-21-2010
pipe program in C
Hello guys,

my professor give me 2 days to study and make a program usign pipe, fork in c

i need to do a program

read a arq.txt
the father process read the file and the child print !

like this
Code:
#include <stdio.h>
#include <stdlib.h>
#include <sys/wait.h>

int main (){
        int std[2];
        FILE *fp;
        unsigned char c;
        pipe(std); 
        if(fork() == 0){ 
                close(0); 
                dup(std[0]); 
                close(std[0]);
                close(std[1]); 
                exit(0); 
        }else{
                close(1); 
                dup(std[1]); 
                close(std[0]); 
                close(std[1]); 
                if(fp = fopen("arq.txt", "rb")){ 
                        fscanf(fp, "%c", &c); 
                        while(!feof(fp)){ 
                                fprintf(stdout,"%c",c); 
                                fscanf(fp, "%c", &c);   
                        }
                        fclose(fp); 
                }
                wait(0); 
        }               
        return(0);
}

but the program doesn't work
and i dont know why
Last edited by jim mcnamara; 11-21-2010 at 11:12 AM.. Reason: code tags
 

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LEARN ABOUT CENTOS

std::locale_facet

std::locale::facet(3)					     Library Functions Manual					     std::locale::facet(3)

NAME

       std::locale::facet -

SYNOPSIS

       Inherited by std::__codecvt_abstract_base< _InternT, _ExternT, encoding_state >, std::__codecvt_abstract_base< char, char, mbstate_t >,
       std::__codecvt_abstract_base< wchar_t, char, mbstate_t >, std::__ctype_abstract_base< wchar_t >, std::__codecvt_abstract_base< _InternT,
       _ExternT, _StateT >, std::__ctype_abstract_base< _CharT >, std::__moneypunct_cache< _CharT, _Intl >, std::__numpunct_cache< _CharT >,
       std::__timepunct< _CharT >, std::__timepunct_cache< _CharT >, std::collate< _CharT >, std::ctype< char >, std::messages< _CharT >,
       std::money_get< _CharT, _InIter >, std::money_put< _CharT, _OutIter >, std::moneypunct< _CharT, _Intl >, std::num_get< _CharT, _InIter >,
       std::num_put< _CharT, _OutIter >, std::numpunct< _CharT >, std::time_get< _CharT, _InIter >, and std::time_put< _CharT, _OutIter >.

   Protected Member Functions
       facet (size_t __refs=0)	throw ()
       virtual ~facet ()

   Static Protected Member Functions
       static __c_locale _S_clone_c_locale (__c_locale &__cloc)  throw ()
       static void _S_create_c_locale (__c_locale &__cloc, const char *__s, __c_locale __old=0)
       static void _S_destroy_c_locale (__c_locale &__cloc)
       static __c_locale _S_get_c_locale ()
       static const char * _S_get_c_name ()  throw ()
       static __c_locale _S_lc_ctype_c_locale (__c_locale __cloc, const char *__s)

   Friends
       class locale
       class locale::_Impl

Detailed Description
       Localization functionality base class.

       The facet class is the base class for a localization feature, such as money, time, and number printing. It provides common support for
       facets and reference management.

       Facets may not be copied or assigned.

       Definition at line 338 of file locale_classes.h.

Constructor &; Destructor Documentation
   std::locale::facet::facet (size_t__refs = 0) [inline],  [explicit],	[protected]
       Facet constructor. This is the constructor provided by the standard. If refs is 0, the facet is destroyed when the last referencing locale
       is destroyed. Otherwise the facet will never be destroyed.

       Parameters:
	   __refs The initial value for reference count.

       Definition at line 370 of file locale_classes.h.

   virtual std::locale::facet::~facet () [protected],  [virtual]
       Facet destructor.

Author
       Generated automatically by Doxygen for libstdc++ from the source code.

libstdc++							  Tue Jun 10 2014					     std::locale::facet(3)
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