Hi
I know its a dumb question but can any one please explain me the difference of executing a shell script in the following 2 ways.
. script.sh
sh script.sh
I have a problem if I execute the following code as sh script.sh
DB_CNT_ALW=0.20
SCT_VAR=0.05
if ; then
echo "== Difference... (3 Replies)
Hi Guys,
Thank you all for helping me with my different queries and I continue to get better at scripting because of help from all of you!
I have a file that would look something like -
ID SUB ID VALUE
1 10 5
2 18 7
1 ... (1 Reply)
Hi all,
I am new to unix and I am trying hard to get this requirement, but no luck.
I am trying to compare two cloumns in two files and if it matches, the last column in file1 must be divided by file2 and the output must be written in a new file. To elaborate the 2nd column in file1 (EUR) must be... (6 Replies)
- I have two files (File 1 and File 2) and the contents of the files are mentioned below.
- I am trying to compare the values of Column1 of File1 with Column1 of File2. If a match is found, print the corresponding value from Column2 of File1 in Column5 of File2.
- I tried to modify and use... (10 Replies)
Hi All,
I have a big file with 232 columns and 9 million rows, I want to delete all rows with same column values in col3 through col232. Also the output should be sorted based on first 2 columns.
Here is a reduced example with 6 columns. I want to remove rows with duplicate values in col3... (9 Replies)
data file contains
failed=24
error=23
error=163
failed=36
error=903
i need to get a total count of each value above. i'm looking for the most efficient method to do this as the datafile i provided is just a sample. the actual data can be several hundred thousands of lines.
so from... (3 Replies)
I/P:
I/P:
2017/01/01 a 10
2017/01/01 b 20
2017/01/01 c 40
2017/02/01 a 10
2017/02/01 b 20
2017/02/01 c 30
O/P:
a b c
2017/01/01 10 20 40
2017/02/01 10 20 30 (18 Replies)
I would like to compare values in column 8, and grep the ones where the different is > 1, columns 1 and 2 are the key for array.
Every 4 rows the records values in columns 1 and 2 changed. Then, the comparison in the column 8 need to be done for the 4 rows everytime columns 1 and 2 changed
... (4 Replies)
Discussion started by: jiam912
4 Replies
LEARN ABOUT DEBIAN
log::log4perl::config::watch
Config::Watch(3pm) User Contributed Perl Documentation Config::Watch(3pm)NAME
Log::Log4perl::Config::Watch - Detect file changes
SYNOPSIS
use Log::Log4perl::Config::Watch;
my $watcher = Log::Log4perl::Config::Watch->new(
file => "/data/my.conf",
check_interval => 30,
);
while(1) {
if($watcher->change_detected()) {
print "Change detected!
";
}
sleep(1);
}
DESCRIPTION
This module helps detecting changes in files. Although it comes with the "Log::Log4perl" distribution, it can be used independently.
The constructor defines the file to be watched and the check interval in seconds. Subsequent calls to "change_detected()" will
o return a false value immediately without doing physical file checks if "check_interval" hasn't elapsed.
o perform a physical test on the specified file if the number of seconds specified in "check_interval" have elapsed since the last
physical check. If the file's modification date has changed since the last physical check, it will return a true value, otherwise a
false value is returned.
Bottom line: "check_interval" allows you to call the function "change_detected()" as often as you like, without paying the performing a
significant performance penalty because file system operations are being performed (however, you pay the price of not knowing about file
changes until "check_interval" seconds have elapsed).
The module clearly distinguishes system time from file system time. If your (e.g. NFS mounted) file system is off by a constant amount of
time compared to the executing computer's clock, it'll just work fine.
To disable the resource-saving delay feature, just set "check_interval" to 0 and "change_detected()" will run a physical file test on every
call.
If you already have the current time available, you can pass it on to "change_detected()" as an optional parameter, like in
change_detected($time)
which then won't trigger a call to "time()", but use the value provided.
SIGNAL MODE
Instead of polling time and file changes, "new()" can be instructed to set up a signal handler. If you call the constructor like
my $watcher = Log::Log4perl::Config::Watch->new(
file => "/data/my.conf",
signal => 'HUP'
);
then a signal handler will be installed, setting the object's variable "$self->{signal_caught}" to a true value when the signal arrives.
Comes with all the problems that signal handlers go along with.
TRIGGER CHECKS
To trigger a physical file check on the next call to "change_detected()" regardless if "check_interval" has expired or not, call
$watcher->force_next_check();
on the watcher object.
DETECT MOVED FILES
The watcher can also be used to detect files that have moved. It will not only detect if a watched file has disappeared, but also if it has
been replaced by a new file in the meantime.
my $watcher = Log::Log4perl::Config::Watch->new(
file => "/data/my.conf",
check_interval => 30,
);
while(1) {
if($watcher->file_has_moved()) {
print "File has moved!
";
}
sleep(1);
}
The parameters "check_interval" and "signal" limit the number of physical file system checks, simililarily as with "change_detected()".
COPYRIGHT AND LICENSE
Copyright 2002-2009 by Mike Schilli <m@perlmeister.com> and Kevin Goess <cpan@goess.org>.
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
perl v5.10.1 2010-07-21 Config::Watch(3pm)