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Full Discussion: terminal problem
Top Forums Programming terminal problem Post 302102696 by heck on Friday 12th of January 2007 07:48:02 AM
Old 01-12-2007
inherited file descriptors
i am not sure but, i could be the following reason:

Open descriptors are inherited to child process, this may cause the use of resources unneccessarily. Unneccesarry descriptors should be closed before fork() system call (so that they are not inherited) or close all open descriptors as soon as the child process starts running.
Code:
	for (i=getdtablesize();i>=0;--i) close(i); /* close all descriptors */

There are three standart I/O descriptors: standart input 'stdin' (0), standart output 'stdout' (1), standart error 'stderr' (2). A standard library routine may read or write to standart I/O and it may occur to a terminal or file. For safety, these descriptors should be opened and connectedthem to a harmless I/O device (such as /dev/null).

Code:
i=open("/dev/null",O_RDWR); /* open stdin */
	dup(i); /* stdout */
	dup(i); /* stderr */

As Unix assigns descriptors sequentially, fopen call will open stdin and dup calls will provide a copy for stdout and stderr.

Be aware that system() from <cstdlib> or <stdlib.h> is sth. like a wrapper for fork() and exec(). popen() too as far as is know.

But, try this.

I would be helpfull if we knew what you are executing and what output you have on the screen.
cheeers
 

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LEARN ABOUT DEBIAN

clp

CLP(1)							      General Commands Manual							    CLP(1)

NAME

       clp - linear program solver

SYNOPSIS

       clp filename [ options ] solutionfile

DESCRIPTION

       This manual page documents briefly the clp command.

       clp -- interface to the coin linear programming solver. clp solves the following linear optimization program:

	   minimize	 c^t x
	   such that:	 row_lb <= Ax <= row_ub
			 column_lb <= x <= column_ub

OPTIONS

       When  no options are given clp enters the interactive command line mode.  Otherwise the program enters a batch mode, for which a summary of
       options is included below.  For a complete description, see /usr/share/doc/coinor-libclp-doc.

       -help  Show summary of options.

       -primalsimplex
	      solve the problem using the primal simplex method

       -dualsimplex
	      solve the problem using the dual simplex method

       -maximize
	      maximize the problem

SEE ALSO

       glpsol(1),dsdp5(1)

       This program is fully documented in the accompanying html documentation which can  be  found  in  /usr/share/doc/coinor-libclp-doc  if  the
       coinor-libclp-doc package is installed.

AUTHOR

       clp was written by John J. Forrest <jjforre@us.ibm.com> et.al.

       This manual page was written by Soeren Sonnenburg <sonne@debian.org>, for the Debian project (but may be used by others).

								   May	7, 2008 							    CLP(1)
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