Fail tail algorithm Post: 90450

Sponsored Content

Top Forums Programming Fail tail algorithm Post 90450 by Perderabo on Tuesday 22nd of November 2005 07:00:22 PM

11-22-2005

Administrator Emeritus

Actually, fwrite and other stdio routines use a buffer that is private to the process. There is no general way to induce a program to empty its stdio buffers. And sync() never did affect the stdio buffers. On the other hand read() and write() go through the buffer cache or equivalent structure. The data is in core, but it is immediately available to other processes. sync() used to empty the buffer cache. Today sync() might just flush metadata.

As for the original question, why is this real time response needed? What is the consequence of, say, an extra 50 ms delay. How many writes would you expect during an average second? Are there frequent periods several seconds at a time without activity? What OS is in use? Would the 3rd party be willing to unbuffer the data? Can you specify the output file? What happens if the file already exists when the 3rd party program starts?

Perderabo

View Public Profile for Perderabo

Find all posts by Perderabo

9 More Discussions You Might Find Interesting

1. Programming

Feedback algorithm

Hi I search an exemple of scheduling Feedback algorithm, or help about how to create one. Thanks

2. Programming

Algorithm problem

Looking for an algorithm to compute the number of days between two given dates I came across a professor's C program located here: http://cr.yp.to/2001-275/struct1.c I was wondering if anyone could tell me where the value 678882 in the line int d = dateday - 678882; comes from and also the...

3. Programming

FTP's algorithm

what algorithm a FTP application uses i mean whn implemented in socket programming..if you could give a little decription

4. Shell Programming and Scripting

algorithm

PID USERNAME SIZE RSS STATE PRI NICE TIME CPU PROCESS/NLWP 21444 tomusr 213M 61M sleep 29 10 1:20:46 0.1% java/43 21249 root 93M 44M sleep 29 10 1:07:19 0.2% java/56 is there anyway i can use a command to get the total of the SIZE? 306M (Derive from...

5. Programming

Please help me to develop algorithm

Hi guys , in my study book from which I re-learn C is task to generate all possible characters combination from numbers entered by the user. I know this algorithm must use combinatorics to calculate all permutations. Problem is how to implement algortihm. // This program reads the four numbers...

6. Programming

Looking for Your Help on dijkstra algorithm

Can you help to adjust the void dijkstra(int s) function to find a path from source to every node so that the minimum cost on that path is maximum. Ex: From 1 to 2 we have 1 - 3 - 4 - 2 , costs(2+3+4+5) From 1 to 2 we have 1 - 5 - 6 - 2 , costs(3+3+4+5) I need the algorithm to choose path 1...

7. Shell Programming and Scripting

Joining multiple files tail on tail

I have 250 files that have 16 columns each - all numbered as follows stat.1000, stat.1001, stat.1002, stat.1003....stat.1250. I would like to join all 250 of them together tail by tail as follows. For example stat.1000 a b c d e f stat.1001 g h i j k l So that my output...

8. Shell Programming and Scripting

Masking algorithm

I have a requirement of masking few specific fields in the UNIX file. The details are as following- File is fixed length file with each record of 250 charater length. 2 fields needs to be masked – the positions are 21:30 and 110:120 The character by character making needs to be done which...

9. Shell Programming and Scripting

When redirecting tail -F output fail after log rotation?

Redirecting the tail output fails when log rotation happens even though i have used -F. But when i tail and see the output on terminal this does not happen. Note i have also used & to execute this statement in background. Suppose if i want to tail a file /opt/SAMPLE.txt and redirect its output...

LEARN ABOUT DEBIAN

mtail

MTAIL(1)							   User Commands							  MTAIL(1)

NAME

       mtail - tail variant designed for web developers monitoring logfiles

SYNOPSIS

       mtail [options]	<file>...

DESCRIPTION

       MonkeyTail  allows  a  user to tail multiple files on both local and remote hosts and clearly marks inactivity by putting 5 newlines in the
       output whenever a pause in output over 3 seconds is detected.

       MonkeyTail is implemented a fairly simple wrapper script around standard tail, ssh, and sudo.

OPTIONS

       -q     Quiet mode

       --quiet
	      "    "

       -n     Output the last N lines of each file before tailing (defaults to 0)

       <file>...
	      Files to tail.

	      These can specified in the following ways:

       @<groupname>
	      - expands the group (from .mtailrc) to a list of

	      files to tail

       <filename>
	      - tails a local file.

       +<filename>		- attempts to sudo and tail a local file (will
	      prompt for pwd if required).

       <remotehost>:<filename>
	      - attempts to invoke tail via ssh on a remote

	      host.

       +<remotehost>:<filename> - attempts to invoke sudo tail via ssh on a
	      remote host (will prompt for pwd if required).

SEE ALSO

       mtailrc(5), tail(1)

AUTHOR

       Martyn Smith <martyn@dollyfish.net.nz>

mtail								     May 2008								  MTAIL(1)