Hi,
I am a beginner in shell scripting. I have written the following script, which is supposed to process the while loop for each line in the sid_home.txt file. But I'm getting the 'end of file' unexpected for the last line. The file sid_home.txt gets generated as expected, but the script... (6 Replies)
Hi -
I have a file that contains data in this format:-
#comment
value1 value2 value3
#comment
value4 value5 value6 value7
#comment
value8 value9
I need to read value1, value2 and value3 into one array, value4 value5 value6 and value7 into another array and value8 and value9 into a 3rd... (2 Replies)
So, I want to read line-by-line a text file with unknown number of files....
So:
a=1
b=1
while ; do
b=`sed -n '$ap' test`
a=`expr $a + 1`
$here do something with b etc
done
the problem is that sed does not seem to recognise the $a, even when trying
sed -n ' $a p'
So, I cannot read... (3 Replies)
So, the beginning of my script will cat & grep a file with the output directed to a new file. The data I have in this file needs to be parsed, read and evaluated.
Basically, I need to identify the latest date/time stamp and then calculate whether or not it is within 15 minutes of the current... (1 Reply)
Hi,
I have a shell script 'sample.sh' which has some functions as below.
#fun1
fun1()
{
date
}
#fun2()
{
echo hi
}
I want to run these functions as background processes and also redirect the output to a file. My function calling statements are in a different file 'sample.cfg' as... (3 Replies)
I need some help. I would like to read in a text file.
Take a variable such as ROW-D-01, compare it to what's in one line in the text file such as PROD/VM/ROW-D-01 and only input PROD/VM into a variable without the /ROW-D-01.
Is this possible? any help is appreciated. (2 Replies)
Hi,
i have a scenario were i should compare a few fields from each line then increment a variable based on that.
Example file
989878|8999|Y|0|Y|N|V
989878|8999|Y|0|N|N|V
989878|8999|Y|2344|Y|N|V
i have 3 conditions to check and increment a variable on every line
condition 1 if ( $3... (4 Replies)
Hi,
I want to read a live log file line by line and considering those line which start from time stamp;
Below code I am using, which read line but throws an exception when comparing line that does not contain error code
tail -F /logs/COMMON-ERROR.log | while read myline; do... (2 Replies)
Hi All,
i want to write a shell script read below file line by line and want to exclude the lines which contains empty value for MOUNTPOINT field.
i am using centos 7 Operating system.
want to read below file.
# cat /tmp/d5
NAME="/dev/sda" TYPE="disk" SIZE="60G" OWNER="root"... (4 Replies)
Discussion started by: balu1234
4 Replies
LEARN ABOUT CENTOS
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)