i made a lot of processes. here is the code:
main()
{
printf("\nEnter K="); scanf("%d",&k);
printf("Enter L="); scanf("%d",&l);
printf("\nFather id=%d\n",getpid());
x=0;
makechild();
sleep(2);
return 1;
}
int makechild()
{
for(q=1;q<=k;q++)
{
if(f=fork())
{
... (5 Replies)
Hi
I tried to open the man page of sh and piped to `pg`. Normally while reading a file page by page using `pg`, if we wanna quit at the middle of file, we give "q" near the colon mode.
Ex1: $cat file1 | pg
hi
how
r
u
: (page1) now press "return key", it will go to next page
yes
i ... (1 Reply)
Hi
I tried to open the man page of sh and piped to `pg`. Normally while reading a file page by page using `pg`, if we wanna quit at the middle of file, we give "q" near the colon mode.
Ex1: $cat file1 | pg
hi
how
r
u
: (page1) now press "return key", it will go to next page
yes
i ... (3 Replies)
hi guys, o have a big error
in this program but i cant solve
someone ?!
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
int main(int argc, char *argv){
int cont = 2, posicao;
char geraArquivo= "|cat>>", espaco=" ";
char nomeArquivo, comando,... (11 Replies)
I want to do the following in perl:
print $output | grep ' something' | awk '{print $2}';
I know there is system(); but it does not behave the way I was expecting it in perl. (2 Replies)
Hi guys.
I've a problem with pipes, I'm trying to make a program that can create a child process and they must generate the folowing output:
Ping ... Pong
Ping ... Pong
Ping ... Pong
I want syncronize the output whithout using the semephores, can anyone help me?
Thanks in advance.
/**
*... (1 Reply)
Hi all,
I would like to use properly an input pipe, like this :
cat myFile.txt | myCommand.shI always find this solution :
while read line; do ...; donebut I have a great lost of performance !
On a big file, with a simple grep, I can spend 2400 times more time ! oO
(from 0,023sec to 1m)... (4 Replies)
Hi guys,
I need to know how i can ignore Pipe '|' if Pipe is coming as a column in Pipe delimited file
for eg:
file 1:
xx|yy|"xyz|zzz"|zzz|12...
using below awk command
awk 'BEGIN {FS=OFS="|" } print $3
i would get xyz
But i want as :
xyz|zzz to consider as whole column... (13 Replies)
Discussion started by: rohit_shinez
13 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)
03-02-2011
