You are getting error output from ping - change the command
Code:
ping -c 3 www.primus.ca 2>&1
# or if you don't want errors
ping -c 3 www.primus.ca > /dev/null
When you have a subprocess running it generates a system signal (which is being trapped by popen and reported). The signal is SIGTTOU. You cannot use popen without trapping stderr output or blocking signals.
Hi ,
I m actually trying to implement pipes program,but after executing the execvp(),my program is getting hanged up :mad:
Actaully i m getting the desired output expected from execvp()...but once results are displayed on the output screen ,program is getting hanged up
values of... (3 Replies)
Hi,
I wanted to know if i can write a program using switches and signals, etc to trace execution of other unix program which calls c program internally.
If yes how? If not with signals and switches then are there any other methods apart from debugging with gdb/dbx. (3 Replies)
I have made use of 'valgrind' and -finstrument-functions compiler option for debugging / analyzing code. Both the options lets us know the line / file being executed to some extent.
Is there a generic way that lets program dump the file:line it is getting executed dumped to a log file during... (3 Replies)
Hello experts,
How can I retrieve the output from a Unix command and use it as string variable in my C program?
For example, when I issue the command 'date' I get:
Tue Jun 11 09:54:16 EEST 2009
I do not want to redirect the output of the command to a file and then open the file from... (3 Replies)
I'm trying to execute a script from within my java code. The execution of the script is over(it's pid is no more), but java is stuck on waitFor() method of the shell script process!. And yes, I'm reading output and error streams in 2 separate threads. Yes, they are being joined at the end(after... (0 Replies)
//Find the root of the equation (x^2)-2 by bisection method.
#include<iostream>
using namespace std;
double a,x;
double f(double x)
{
return ((x*x)-2);
} //Suppose the function is (x*x)-2.
void calcx(double a1,double b1)
{
x =... (2 Replies)
I am scheduling a task at regular intervals at seconds acuracy using crond and sleep command . my data in crontab file is as below:-
the above line is working fine when we are creating this crontab file before 00:05 min .
But when we are creating the crontab file at 00:05min , unable to... (10 Replies)
I have a ksh script (script1) that calls another ksh script (script2). If script2.ksh hangs or takes too long to execute I want script1.ksh to kill the call to script2.ksh and instead just display "Script2 can't run right now". Could someone help me with coding this? (1 Reply)
I need UNIX scripts for polling, Uncompressing files and moving files between directory. Also trying to save file paths and any other variables in an independent file (.env) and use these at runtime by executing this file in the main script. (3 Replies)
I have two programs, DriverScale.c and scale9.c. DriverScale.c calls scale 9.c which sends a W and a carraige return to the scale which SHOULD return the weight to DriverScale. However scale 9 hangs for at least 10 min, and then finally returns the weight.
Compilation:
... (8 Replies)
Discussion started by: Meow613
8 Replies
LEARN ABOUT DEBIAN
explain_popen_or_die
explain_popen_or_die(3) Library Functions Manual explain_popen_or_die(3)NAME
explain_popen_or_die - process I/O and report errors
SYNOPSIS
#include <libexplain/popen.h>
FILE *explain_popen_or_die(const char *command, const char *flags);
DESCRIPTION
The explain_popen_or_die function is used to call the popen(3) system call. On failure an explanation will be printed to stderr, obtained
from explain_popen(3), and then the process terminates by calling exit(EXIT_FAILURE).
This function is intended to be used in a fashion similar to the following example:
FILE *fp = explain_popen_or_die(command, flags);
command The command, exactly as to be passed to the popen(3) system call.
flags The flags, exactly as to be passed to the popen(3) system call.
Returns:
This function only returns on success, see popen(3) for more information. On failure, prints an explanation and exits.
SEE ALSO popen(3)
process I/O
explain_popen(3)
explain popen(3) errors
exit(2) terminate the calling process
COPYRIGHT
libexplain version 0.52
Copyright (C) 2009 Peter Miller
explain_popen_or_die(3)