I have a huge file, I am currently using while loop to read and do some calculation on it, but it is taking a lot of time.
I want to use AWK to read and do those calculations.
Please suggest.
currently doing:
Last edited by Scrutinizer; 12-12-2012 at 01:43 AM..
Reason: code tags
Hello all,
I need some help to create a script which contain a few strings on every line, and use those strings in a loop to fire some commands.
for exmaple the file looks like
tom
dave
bill
andy
paul
I want to read one line at a time and use it in loop like
command tom
command dave... (3 Replies)
Guys,
I am trying to read the whole file using while loop but when i run the ssh part of the script it reads only the first line and exit after that.
There are in total 134 lines in the file, but when the output is redirected, it does only for one line and comes to command prompt.
pls help..... (11 Replies)
I know I should be able to see a way of doing this easily, but my brain just won't engage.
I have a script working on an embedded device that checks to see if an item is in a blacklist before performing some actions.
At the moment the code reads thus....
while read BLACKLIST ; do
... (7 Replies)
I have written a script to read the file line by line.
It is reading and printing the lines.
But it is coming out of loop before reading last line.
So I am not able to print last line.
How do I solve it. (6 Replies)
Hi
As a newbe in scripting, i struggle hard with my first script.
What i want to do is, bringing data of two files together.
file1:
....
05/14/12-04:00:00 41253 4259 5135 5604 5812 5372
05/14/12-04:10:00 53408 5501 6592 7402 7354 6639
05/14/12-04:20:00 58748 6037 7292 8223... (13 Replies)
Hello,
I have a set of files Xfile0001 - Xfile0021, and the content of this files (one at a time) needs to be printed between some line (lines start with word "Generated") that I am extracting from another file called file7.txt and all the output goes into output.txt. First I tried creating a for... (5 Replies)
Hello,
I am using below code for reading from a file and assigning the values to a variable , but it is loosing the value after the loop , please suggest to retain the value of the variable after the loop ,
while IFS=: read -r line
do
set $dsc=$line
echo 'printing line variable ' $line... (1 Reply)
I have a file1.txt with several 100k lines, each of which has a column 9 containing one of 60 "label" identifiers. Using an labels.txt file containing a list of labels, I'd like to extract 200 random lines from file1.txt for each of the labels in index.txt.
Using a contrived mini-example:
$ cat... (8 Replies)
I have files named with different prefixes. From each I want to extract the first line containing a specific string, and then print that line along with the prefix.
I've tried to do this with a while loop, but instead of printing the prefix I print the first line of the file twice.
Files:... (3 Replies)
Discussion started by: pathunkathunk
3 Replies
LEARN ABOUT SUSE
unbuffer
UNBUFFER(1) General Commands Manual UNBUFFER(1)NAME
unbuffer - unbuffer output
SYNOPSIS
unbuffer program [ args ]
INTRODUCTION
unbuffer disables the output buffering that occurs when program output is redirected from non-interactive programs. For example, suppose
you are watching the output from a fifo by running it through od and then more.
od -c /tmp/fifo | more
You will not see anything until a full page of output has been produced.
You can disable this automatic buffering as follows:
unbuffer od -c /tmp/fifo | more
Normally, unbuffer does not read from stdin. This simplifies use of unbuffer in some situations. To use unbuffer in a pipeline, use the
-p flag. Example:
process1 | unbuffer -p process2 | process3
CAVEATS
unbuffer -p may appear to work incorrectly if a process feeding input to unbuffer exits. Consider:
process1 | unbuffer -p process2 | process3
If process1 exits, process2 may not yet have finished. It is impossible for unbuffer to know long to wait for process2 and process2 may
not ever finish, for example, if it is a filter. For expediency, unbuffer simply exits when it encounters an EOF from either its input or
process2.
In order to have a version of unbuffer that worked in all situations, an oracle would be necessary. If you want an application-specific
solution, workarounds or hand-coded Expect may be more suitable. For example, the following example shows how to allow grep to finish pro-
cessing when the cat before it finishes first. Using cat to feed grep would never require unbuffer in real life. It is merely a place-
holder for some imaginary process that may or may not finish. Similarly, the final cat at the end of the pipeline is also a placeholder
for another process.
$ cat /tmp/abcdef.log | grep abc | cat
abcdef
xxxabc defxxx
$ cat /tmp/abcdef.log | unbuffer grep abc | cat
$ (cat /tmp/abcdef.log ; sleep 1) | unbuffer grep abc | cat
abcdef
xxxabc defxxx
$
BUGS
The man page is longer than the program.
SEE ALSO
"Exploring Expect: A Tcl-Based Toolkit for Automating Interactive Programs" by Don Libes, O'Reilly and Associates, January 1995.
AUTHOR
Don Libes, National Institute of Standards and Technology
1 June 1994 UNBUFFER(1)