I want to remove a line that has empty string at second field when I use cut with delimeter , like below
$cat demo
hello, mum
hello,
#!/bin/sh
while read line
do
if
then
# remove the current line command goes here
fi
done < "demo"
i got an error message for above... (4 Replies)
Hi
I have this simple script:
#!/bin/bash
date1=2009:07:15:12:36
date2=2009:07:15:12:16
echo $date1
echo $date2
datediff=
#datediff=date1-date2
echo datediff is$datediff
How do i return the difference in seconds? (6 Replies)
1. The problem statement, all variables and given/known data:
I have standard web server log file. It contains different columns (like IP address, request result code, request type etc) including a date column with the format .
I have developed a log analysis command line utility that displays... (1 Reply)
I need to create a script that has a user enter a value. I want to verify that the value is either 1,2, or 3. If it is not then I want them to try entering it again. I am using a while loop to force them to retry.
I am able to test the input against 1,2, and 3, but when I test agains an... (4 Replies)
I have a program to create a directory if not present. Here is the program.
FYI: Directory name format: YYYY_MM_DD
#!/bin/bash
date=`date +%Y_%m_%d`
presence=$(ls -lrt /TS_File/ | grep "$date" | awk '{print $9}')
if
then
mkdir /TS_File/$date
else
echo "Unable to Create... (5 Replies)
continuing from my previous post, whose link is given below as a reference
https://www.unix.com/shell-programming-scripting/171076-shell-scripting.html#post302573569
consider there is create table commands in a file for eg:
CREATE TABLE `Blahblahblah` (
`id` int(11) NOT NULL... (2 Replies)
attempting the hangman program. This was an optional assignment from the professor. I have completed the logical coding, debugging now.
##I have an array $wordString that initializes to a string of dashes
##reflecting the number of letters in $theWord
##every time the user enters a (valid)... (5 Replies)
I have the logic below to look up for matches within the columns between the two files with awk.
In the if statement is where the string comparison is attempted with ==
The issue seems to be with the operands, as
1. when " '${SECTOR}' " -- double quote followed by single quote -- awk matches... (1 Reply)
Discussion started by: deadyetagain
1 Replies
LEARN ABOUT REDHAT
thread::semaphore
Thread::Semaphore(3pm) Perl Programmers Reference Guide Thread::Semaphore(3pm)NAME
Thread::Semaphore - thread-safe semaphores
SYNOPSIS
use Thread::Semaphore;
my $s = new Thread::Semaphore;
$s->up; # Also known as the semaphore V -operation.
# The guarded section is here
$s->down; # Also known as the semaphore P -operation.
# The default semaphore value is 1.
my $s = new Thread::Semaphore($initial_value);
$s->up($up_value);
$s->down($up_value);
DESCRIPTION
Semaphores provide a mechanism to regulate access to resources. Semaphores, unlike locks, aren't tied to particular scalars, and so may be
used to control access to anything you care to use them for.
Semaphores don't limit their values to zero or one, so they can be used to control access to some resource that there may be more than one
of. (For example, filehandles). Increment and decrement amounts aren't fixed at one either, so threads can reserve or return multiple
resources at once.
FUNCTIONS AND METHODS
new
new NUMBER
"new" creates a new semaphore, and initializes its count to the passed number. If no number is passed, the semaphore's count is set
to one.
down
down NUMBER
The "down" method decreases the semaphore's count by the specified number, or by one if no number has been specified. If the sema-
phore's count would drop below zero, this method will block until such time that the semaphore's count is equal to or larger than
the amount you're "down"ing the semaphore's count by.
up
up NUMBER
The "up" method increases the semaphore's count by the number specified, or by one if no number has been specified. This will
unblock any thread blocked trying to "down" the semaphore if the "up" raises the semaphore count above the amount that the "down"s
are trying to decrement it by.
perl v5.8.0 2002-06-01 Thread::Semaphore(3pm)