Sponsored Content
Full Discussion: IPC with PIPE
Top Forums Programming IPC with PIPE Post 302306208 by thanh_sam_khac on Saturday 11th of April 2009 03:13:22 PM
Old 04-11-2009
I try to change the code from while(..) to do{.. } while(..) .. it works..

do
{
c[0]=fgetc(fin); // get each character from inputfile
write(fd[1],c,2); // write to pipe

}
while(c[0]!=EOF)



and it's work.. but wrong result.. Because the last c[0] = EOF, it is written to pipe, then while loop check the codition.. ( wrong ofcourse)..
I include if statement like this:

if(c[0]!= EOF)
{
c[0]=fgetc(fin);// get each character from inputfile
write(fd[1],c,2); // write to pipe

}


Problem again.. The output is blank.. so crazy.. please help me..
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Ipc

I have a parent that is passing data to child A and then child A has to process it and pass to child B. I am able to pass the data to child A but am not able to pass it to child B. Child B seems to only be receiving the last data instead of the whole data. I saw one example in a book but it uses... (1 Reply)
Discussion started by: scmay
1 Replies

2. UNIX for Advanced & Expert Users

IPC using named pipe

Hi All, I am facing a vague issue while trying to make two process talk to each other using named pipe. read process ========= The process which reads, basically creates FIFO using mkfifo - ret_val = mkfifo(HALF_DUPLEX, 0666);) func. It then opens the pipe using open func - fd =... (1 Reply)
Discussion started by: sharanbr
1 Replies

3. Programming

IPC using named pipe

Hi All, I am facing a vague issue while trying to make two process talk to each other using named pipe. read process ========= The process which reads, basically creates FIFO using mkfifo - ret_val = mkfifo(HALF_DUPLEX, 0666) func. It then opens the pipe using open func - fd = open... (2 Replies)
Discussion started by: sharanbr
2 Replies

4. Solaris

errors on Netra-440: "IPC Warning: ipc: tcp_protocol: bad magic number"

I was asked to look into a problem with a Sun Netra 440 in another department. On the server in question, the relevant 'uname -a' information is, "SunOS host1 5.9 Generic_118558-16 sun4u sparc SUNW,Netra-440". That information aside, while the other admin is logged into the ALOM, these errors are... (0 Replies)
Discussion started by: Borealis
0 Replies

5. Programming

IPC Mechanisms

Hi! I wanted to know the advantages / disadvantages of different IPC mechanims such as sockets, pipes (unnamed) , shared memory & message queues. Pipes for example i hear are fast , but are difficult to debug as compared to sockets. Can you guys please name some situations where one is... (4 Replies)
Discussion started by: _korg
4 Replies

6. Shell Programming and Scripting

Replace pipe with Broken Pipe

Hi All , Is there any way to replace the pipe ( | ) with the broken pipe (0xA6) in unix (1 Reply)
Discussion started by: saj
1 Replies

7. Programming

Best IPC mechanism to be used

Suppose I have 5 independent process divided in two imaginay sets: set1 set2 --------------------- p1 p3 | | p2 p4 | p5 The processes inside each set communicate mutually quite often. I mean p1 and p2 communicate mutually quite often Similarly p3, p4 and p5 communicate mutually... (2 Replies)
Discussion started by: rupeshkp728
2 Replies

8. HP-UX

IPC settings on HP-UX

Hi Experts, Need your help for checking te interprocess communications settings on HP-UX box. Using ipcs command I am able to view Message queue,semapohores etc, but from that output I m not able to understand how to determine if there is any issue with ipc settings and how to resolve that? (1 Reply)
Discussion started by: sai_2507
1 Replies

9. Programming

Problems with pipe IPC

I'm currently studying IPC, I have a first program A: Do an exec for B and wait B: Receive through a fifo a string from a third program "C" and have to resend it to A I was thinking to open a pipe in A before the exec, then passing fd to B as an argument if(pipe(fd)==-1){ ... (1 Reply)
Discussion started by: cifz
1 Replies

10. Shell Programming and Scripting

How to ignore Pipe in Pipe delimited file?

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
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)
All times are GMT -4. The time now is 05:28 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy