I am trying to create a pipe that will direct stdout to in side of the pipe, and stdin to the out side of the pipe - I created two child processes to handle this. However, my pipe doesn't seem to be working correctly. Did I use execv() correctly? Command1[] and command2[] represent the two commands in the pipe statement that is written in a cissh shell (e.g. "ls -C | sort -r). So I want cisshPipe.c to direct stdout to the in side of the pipe and direct stdin to the out side of the pipe so that the command "ls -C | sort -r" would print a sorted list in reverse order of the files in the cissh directory. Below is my code for the pipe function. I'd greatly appreciate help from someone.Thanks!
Last edited by jre247; 04-28-2010 at 10:19 AM..
Reason: Please use code tags!
I don't follow what these are...
this is what my text says...
"When a process is started, a duplicate of that process is created. This new process is called the child and the process that created it is called the parent. The child process then replaces the copy for the code the parent... (1 Reply)
Hello all,
I have gone through the search and looked at posting about idle users and killing processes. Here is my question I would like to kill an idle user ( which I can do) but how can I asure that all of his process is also killed whit out tracing his inital start PID. I have tried this on a... (4 Replies)
Hello.
I have a global function name func1() that I am sourcing in from script A. I call the function from script B. Is there a way to find out which script called func1() dynamically so that the func1() can report it in the event there are errors?
Thanks (2 Replies)
Hi
I am trying to see if there are some options in ps command or if there is a shell script which basically shows you all the processes spawned by a parent process , then all the processes of its child processes and so on down the hierarchy may be like a tree structure. It might be a generic... (6 Replies)
Consider this simple command line
bash -c 'echo $$ ; sleep 10000'This will print the newly created bash PID and sleep for a long time.
If I go to another terminal and do something like
ps -flax | grep leepI'll see something like
501 92418 91910 0 0:00.00 ttys000 0:00.00 bash -c echo $$... (5 Replies)
1. The problem statement, all variables and given/known data:
I need to make an program that in a loop creates one parent and five children with fork(). The problem i'm trying to solve is how to delete the parent and child of the childīs process.
2. Relevant commands, code, scripts,... (0 Replies)
Hi friends,
I have a small question regarding unix system call fork, I hope you will solve my problem. Here is the small program
$ cat fork1.c
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
int main()
{
int pid;
int x = 0;
x = x + 1;
pid = fork();
if(pid < 0)
{... (2 Replies)
Hi everyone
i am very new to linux , working on bash shell.
I am trying to solve the given problem
1. Create a process and then create children using fork
2. Check the Status of the application for successful running.
3. Kill all the process(threads) except parent and first child... (2 Replies)
I am trying to kill PIDs that are tied to a KSH "load_sqlplus" and I am using the below code
LIST_PID=`ps -ef | grep -i "load_sqlplus" | grep -v grep | awk '{print $2}'`
if ; then
echo "Processes killed" "PID : " $LIST_PID
kill -9 $LIST_PID
else
echo "Nothing to Kill"
fi... (4 Replies)
does anyone know how to check in an 'if' statement if a particular directory is a child directory of a particular directory?
help ~ (2 Replies)
Discussion started by: ymc1g11
2 Replies
LEARN ABOUT V7
pipe
PIPE(2) System Calls Manual PIPE(2)NAME
pipe - create an interprocess channel
SYNOPSIS
pipe(fildes)
int fildes[2];
DESCRIPTION
The pipe system call creates an I/O mechanism called a pipe. The file descriptors returned can be used in read and write operations. When
the pipe is written using the descriptor fildes[1] up to 4096 bytes of data are buffered before the writing process is suspended. A read
using the descriptor fildes[0] will pick up the data. Writes with a count of 4096 bytes or less are atomic; no other process can inter-
sperse data.
It is assumed that after the pipe has been set up, two (or more) cooperating processes (created by subsequent fork calls) will pass data
through the pipe with read and write calls.
The Shell has a syntax to set up a linear array of processes connected by pipes.
Read calls on an empty pipe (no buffered data) with only one end (all write file descriptors closed) returns an end-of-file.
SEE ALSO sh(1), read(2), write(2), fork(2)DIAGNOSTICS
The function value zero is returned if the pipe was created; -1 if too many files are already open. A signal is generated if a write on a
pipe with only one end is attempted.
BUGS
Should more than 4096 bytes be necessary in any pipe among a loop of processes, deadlock will occur.
ASSEMBLER
(pipe = 42.)
sys pipe
(read file descriptor in r0)
(write file descriptor in r1)
PIPE(2)