A common thing in shell scripting. I came across this script that will be useful for people learning to write script.
#!/usr/bin/ksh
#
# SCRIPT: 12_ways_to_parse.ksh.ksh
#
#
# REV: 1.2.A
#
# PURPOSE: This script shows the different ways of reading
# a file line by line. Again... (0 Replies)
How many ways are there to open a file in unix?
wha i know is mentioned below
suppose if xx is a filename, then
1) cat xx
2) more xx
3) view xx
4) less xx
I heard there are seven ways to open a file. If so, can anyone tell me all the ways to open a file and correct me the above... (3 Replies)
Backlinks are super important on the web today! Without them your site most likely will not get found by search engine spiders. If your website has been generating low to No traffic then it is probably due to the lack of backlinks.
Below are 10 e-ffective Ways to Get Backlinks!
1. Forum... (0 Replies)
How does X windows system launch a program?
Does X give init a command (fork) or does x give BASH a command? Can/does X interact with init directly or does everything go through BASH? :wall:
Thanks in advance! (4 Replies)
I am trying to figure out the OS version of my Linux box. I got three commands:
# uname -a
Linux test01 2.6.18-238.el5 #1 SMP Thu Jan 13 15:51:15 EST 2011 x86_64 x86_64 x86_64
# cat /proc/version
Linux version 2.6.18-238.el5 (mockbuild@builder10.centos.org) (gcc version 4.1.2 20080704... (4 Replies)
Hello, I need some help to correct my algorithm steps to sum a number. I am confused... please input some steps
Example:
Let's say a number 5.
Now we can get a list of numbers: 1, 2, 3, 4 (less than 5 in sorted order).
so the sum could be: 1+4; 2+3 ( 1+1+1+1+1 or 1+2+2 is not a solution).
... (1 Reply)
Hi I am trying to make my scripts to run from any directory and after some research (googling) I find there are 2 ways to do this
1. export PATH=$PATH:directory
2. create a /bin directory in your home directory and put your scripts there.
Could someone tell me the relative merits of either... (1 Reply)
Okay so I'm 13 and my dad set me a challenge of writing a program that check to see if a box is online with input parameter when starting the program so i came back with this.The top commented out bit is what he showed me how to do after i show him my code.
#!/bin/sh
#in=${@}
#tst=`echo... (3 Replies)
to get the checksum of a file on unix systems, you can just use the "cksum" command.
i discovered there are some watered down versions of unix systems i have to do some work on. surprisingly, these systems have perl installed on them and awk.
so if the cksum command is not available on a... (1 Reply)
Discussion started by: SkySmart
1 Replies
LEARN ABOUT MOJAVE
integer
integer(3pm) Perl Programmers Reference Guide integer(3pm)NAME
integer - Perl pragma to use integer arithmetic instead of floating point
SYNOPSIS
use integer;
$x = 10/3;
# $x is now 3, not 3.33333333333333333
DESCRIPTION
This tells the compiler to use integer operations from here to the end of the enclosing BLOCK. On many machines, this doesn't matter a
great deal for most computations, but on those without floating point hardware, it can make a big difference in performance.
Note that this only affects how most of the arithmetic and relational operators handle their operands and results, and not how all numbers
everywhere are treated. Specifically, "use integer;" has the effect that before computing the results of the arithmetic operators (+, -,
*, /, %, +=, -=, *=, /=, %=, and unary minus), the comparison operators (<, <=, >, >=, ==, !=, <=>), and the bitwise operators (|, &, ^,
<<, >>, |=, &=, ^=, <<=, >>=), the operands have their fractional portions truncated (or floored), and the result will have its fractional
portion truncated as well. In addition, the range of operands and results is restricted to that of familiar two's complement integers,
i.e., -(2**31) .. (2**31-1) on 32-bit architectures, and -(2**63) .. (2**63-1) on 64-bit architectures. For example, this code
use integer;
$x = 5.8;
$y = 2.5;
$z = 2.7;
$a = 2**31 - 1; # Largest positive integer on 32-bit machines
$, = ", ";
print $x, -$x, $x + $y, $x - $y, $x / $y, $x * $y, $y == $z, $a, $a + 1;
will print: 5.8, -5, 7, 3, 2, 10, 1, 2147483647, -2147483648
Note that $x is still printed as having its true non-integer value of 5.8 since it wasn't operated on. And note too the wrap-around from
the largest positive integer to the largest negative one. Also, arguments passed to functions and the values returned by them are not
affected by "use integer;". E.g.,
srand(1.5);
$, = ", ";
print sin(.5), cos(.5), atan2(1,2), sqrt(2), rand(10);
will give the same result with or without "use integer;" The power operator "**" is also not affected, so that 2 ** .5 is always the
square root of 2. Now, it so happens that the pre- and post- increment and decrement operators, ++ and --, are not affected by "use
integer;" either. Some may rightly consider this to be a bug -- but at least it's a long-standing one.
Finally, "use integer;" also has an additional affect on the bitwise operators. Normally, the operands and results are treated as unsigned
integers, but with "use integer;" the operands and results are signed. This means, among other things, that ~0 is -1, and -2 & -5 is -6.
Internally, native integer arithmetic (as provided by your C compiler) is used. This means that Perl's own semantics for arithmetic
operations may not be preserved. One common source of trouble is the modulus of negative numbers, which Perl does one way, but your
hardware may do another.
% perl -le 'print (4 % -3)'
-2
% perl -Minteger -le 'print (4 % -3)'
1
See "Pragmatic Modules" in perlmodlib, "Integer Arithmetic" in perlop
perl v5.18.2 2014-01-06 integer(3pm)