|
|
Sponsored Content
Top Forums
UNIX for Dummies Questions & Answers
Do pipes know when they have to "wait" for all the data?
Post 302412386 by verdepollo on Monday 12th of April 2010 11:25:34 AM
04-12-2010
In general terms, yes. If there is too much data stuck because the other process does not take it out again quickly enough, the original process automatically blocks to guarantee that all data is processed:
Quote:
A sending program may produce 5000 bytes per second, and a receiving program may only be able to accept 100 bytes per second, but no data are lost. Instead, the output of the sending program is held in a buffer, or queue. When the receiving program is ready to read data, the operating system sends it data from the buffer, then removes that data from the buffer. If the buffer fills up, the sending program is suspended (blocked) until the receiving program has had a chance to read some data and make room in the buffer. - Pipeline
|
|
9 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Hi Friends,
Can any of you explain me about the below line of code?
mn_code=`env|grep "..mn"|awk -F"=" '{print $2}'`
Im not able to understand, what exactly it is doing :confused:
Any help would be useful for me.
Lokesha (4 Replies)
Discussion started by: Lokesha
4 Replies
2. Shell Programming and Scripting
Hi
I am writing a bash script on Solaris, that should take n arguments, either appended to the script or taken as output from the last command (similar to grep). What I don't want is that the script waits for user input. In other words:
Possibility 1:
script.sh arg1 arg2 arg3 ...Possibility... (4 Replies)
Discussion started by: g000ze
4 Replies
3. Programming
I am trying to get a better understanding of pipes and processes. I have code in which I link 3 processes A,B,C. I have A->B->C but how would I go about getting C->A?
Here is my code:
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
main()
{
pid_t A, B, C;
int fd;
int fd2;
... (1 Reply)
Discussion started by: tfarmer4
1 Replies
4. Shell Programming and Scripting
Hi,
I have line in input file as below:
3G_CENTRAL;INDONESIA_(M)_TELKOMSEL;SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL
My expected output for line in the file must be :
"1-Radon1-cMOC_deg"|"LDIndex"|"3G_CENTRAL|INDONESIA_(M)_TELKOMSEL"|LAST|"SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL"
Can someone... (7 Replies)
Discussion started by: shis100
7 Replies
5. HP-UX
Hello,
On a HP-UX 10.20 server I've executed something similar to this command:
# echo 'selall;info;wait;infolog;view;done' | /usr/sbin/cstm
But it returns sometype of "argument list too long" error.
I suppose there is a way to fix it by using xargs but I can't figure it out.
Any... (7 Replies)
Discussion started by: asanchez
7 Replies
6. Shell Programming and Scripting
Hi,
I am facing a strange issue,
when i call a script from my while loop in background it doesnt go in background, despite the wait i put below the whil loop it goes forward even before the process put in background is completed.
cat abc.txt | while read -u4 line
do
#if line contains #... (2 Replies)
Discussion started by: mihirvora16
2 Replies
7. UNIX for Dummies Questions & Answers
How to use "mailx" command to do e-mail reading the input file containing email address, where column 1 has name and column 2 containing “To” e-mail address
and column 3 contains “cc” e-mail address to include with same email.
Sample input file, email.txt
Below is an sample code where... (2 Replies)
Discussion started by: asjaiswal
2 Replies
8. Shell Programming and Scripting
Hello.
System : opensuse leap 42.3
I have a bash script that build a text file.
I would like the last command doing :
print_cmd -o page-left=43 -o page-right=22 -o page-top=28 -o page-bottom=43 -o font=LatinModernMono12:regular:9 some_file.txt
where :
print_cmd ::= some printing... (1 Reply)
Discussion started by: jcdole
1 Replies
9. AIX
Hi 2 all,
i have had AIX 7.2
:/# /usr/IBMAHS/bin/apachectl -v
Server version: Apache/2.4.12 (Unix)
Server built: May 25 2015 04:58:27
:/#:/# /usr/IBMAHS/bin/apachectl -M
Loaded Modules:
core_module (static)
so_module (static)
http_module (static)
mpm_worker_module (static)
... (3 Replies)
Discussion started by: penchev
3 Replies
LEARN ABOUT HPUX
datalock
datalock(3C) datalock(3C) NAME
datalock() - lock process into memory after allocating data and stack space SYNOPSIS
DESCRIPTION
allocates at least datsiz bytes of data space and stsiz bytes of stack space, then locks the program in memory. The data space is allo- cated by (see malloc(3C)). After the program is locked, this space is released by (see malloc(3C)), making it available for use. This allows the calling program to use that much space dynamically without receiving the signal. The effective user ID of the calling process must be super-user or be a member of or have an effective group ID of a group having PRIV_MLOCK access to use this call (see setprivgrp(2) in getprivgrp(2)). EXAMPLES
The following call to allocates 4096 bytes of data space and 2048 bytes of stack space, then locks the process in memory: RETURN VALUE
returns -1 if cannot allocate enough memory or if returned an error (see plock(2)). WARNINGS
Multiple datalocks cannot be the same as one big one. Methods for calculating the required size are not yet well developed. AUTHOR
was developed by HP. SEE ALSO
getprivgrp(2), plock(2), thread_safety(5). datalock(3C)