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Full Discussion: read and write stdin/stdout in unix
Top Forums Programming read and write stdin/stdout in unix Post 302414793 by MrUser on Wednesday 21st of April 2010 03:31:08 AM
Old 04-21-2010
read and write stdin/stdout in unix
Hi,
i am using the below program to read from the standard input or to write to standard out put.

i know that using highlevel functions this can be done better than what i have done here.

i just want to know is there any other method by which i find the exact number of characters ( this will vary in each iteration ) , and write that to STDOUT.

this process i want to terminate with a press of "q".

does read syscall stores the null at the end of string, i have not found that in debug mode.

below is the sample code but its has got the problem of reading and writing garbages.


Code:
#include<unistd.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<fcntl.h>
#include <stdio.h>
#include<string.h>

int main( void )
{
        char buf[20];

        while( 1 )
        {
                       read(STDIN_FILENO , buf ,  sizeof( buf ));
                       write(STDOUT_FILENO, buf , strlen( buf ));

                if(!strcmp(buf,"q\n"))
                        break;
        }

        return 0;
}

 

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LEARN ABOUT DEBIAN

ts2es

TS2ES(1)							   User Commands							  TS2ES(1)

NAME

       ts2es - extract a single (elementary) stream from a TS (or PS)

SYNOPSIS

       ts2es [switches] <infile> <outfile>

DESCRIPTION

	      TS tools version 1.11, ts2es built Nov 11 2008 17:15:45

	      Extract a single (elementary) program stream from a Transport Stream (or Program Stream).

   Files:
       <infile>
	      is an H.222 Transport Stream file (but see -stdin and -pes)

	      <outfile> is a single elementary stream file (but see -stdout)

   Which stream to extract:
       -pid <pid>
	      Output data for the stream with the given <pid>. Use -pid 0x<pid> to specify a hex value

       -video Output data for the (first) video stream named in the (first) PMT. This is the default.

       -audio Output data for the (first) audio stream named in the (first) PMT

   General switches:
       -stdin Input from standard input, instead of a file

       -stdout
	      Output to standard output, instead of a file Forces -quiet.

       -verbose, -v
	      Output informational/diagnostic messages

       -quiet, -q
	      Only output error messages

       -max <n>, -m <n>
	      Maximum number of TS packets to read

       -pes, -ps
	      Use  the	PES interface to read ES units from the input file. This allows PS data to be read (there is no point in using this for TS
	      data).  Does not support -pid, -stdin or -stdout.

	      TS tools version 1.11, ts2es built Nov 11 2008 17:15:45

	      Extract a single (elementary) program stream from a Transport Stream (or Program Stream).

   Files:
       <infile>
	      is an H.222 Transport Stream file (but see -stdin and -pes)

	      <outfile> is a single elementary stream file (but see -stdout)

   Which stream to extract:
       -pid <pid>
	      Output data for the stream with the given <pid>. Use -pid 0x<pid> to specify a hex value

       -video Output data for the (first) video stream named in the (first) PMT. This is the default.

       -audio Output data for the (first) audio stream named in the (first) PMT

   General switches:
       -stdin Input from standard input, instead of a file

       -stdout
	      Output to standard output, instead of a file Forces -quiet.

       -verbose, -v
	      Output informational/diagnostic messages

       -quiet, -q
	      Only output error messages

       -max <n>, -m <n>
	      Maximum number of TS packets to read

       -pes, -ps
	      Use the PES interface to read ES units from the input file. This allows PS data to be read (there is no point in using this  for	TS
	      data).  Does not support -pid, -stdin or -stdout.

SEE ALSO

       The full documentation for ts2es is maintained as a Texinfo manual.  Please check http://tstools.berlios.de for more information.

ts2es 1.11							   November 2008							  TS2ES(1)
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