s is the string you want to perform the substr operation on i is the first character that you want to extract n is the last character you want to match
So if you said substr( "hello", 2, 4 ) it would match the second, third and fourth character and return ell.
Let me explain the code I gave
In the above example, the first argument to substr is $0 (which in this case is the text piped to it - "$0" is the entire record). The second argument is 0 (I could also have used 1) because I want to match from the start of the string. I want to grab the first four characters, so the third argument is 4.
The above code also makes use length(string) command to return the number of characters in the string.
So here, I'm saying "return the substring from the first character (which is the length of the string minus 3), up until the very end of the string".
To clarify this:
So in our substr, we grab from character 4 to character 7 inclusive, which are chars 4,5,6,7 - the last 4 chars.
how to parse the command line argument to look for '@' sign and the following with '.'.
In my shell script one of the argument passed is email address. I want to parse this email address to look for correct format.
rmjoe123@hotmail.com has '@' sign and followed by a '.'
to be more... (1 Reply)
Hi,
I have a requirement. I have an application which can take a file as inputs. Now the file can contain any number of lines. The tool has to pick up the first uncommented line and begin processing it.
For example the file could be like this:
#MANI123|MANI1234
#MANI234|MANI247... (4 Replies)
I have record line somthing like below with first line showing char spacing not real record line
1 | 2 | 3rd Field--------------|-4th field--| This is charcatersapcing of line
DF20000000000000000130.7890000000750
I shoudl get two line from above line
1st line should
1 | 2 | 3rd... (3 Replies)
#I'm quite new to scripting and my boss has asked me to solve a simple problem and sadly, I can't figure out how to do it. Any help is appreciated.
:confused:
#The following is a small shell script and the output that it produces for google.com.
#!/bin/sh
whois $1 | grep "Name Server"... (5 Replies)
Hey guys,
I have this file generated by me... i want to create some HTML output from it.
The problem is that i am really confused about how do I go about reading the file.
The file is in the following format:
TID1 Name1 ATime=xx AResult=yyy AExpected=yyy BTime=xx BResult=yyy... (8 Replies)
Hi everybody, I have a string stored in a variable called record:
record="SNMPv2-SMI::ent.9.9.43.1.3.9.2 = Timeticks: (177330898) 20 days, 12:35:08.98"
I want to write some regular expressions good for Korn Shell to extract the number between parenthesis, in this case 177330898, and put it in... (3 Replies)
I have a xml file like this
<bul:collectionStrategy name="strategy1">
<bul:collectionTemplateGroup name="15min group"/>
<bul:collectionTemplateGroup name="hourly group"/>
</bul:collectionStrategy>
<bul:CollectionTemplateGroup name="hourly group" >
... (2 Replies)
I have a file parameters.txt which contains
151524
151525
I have another file OID.csv which contains
NE Version Object Type ID SDK param name Object OID
test1 Start: 4.2 End: 4.2 pan 151524 speed ... (5 Replies)
Well, issue is i have to parse this script to get the VERSION:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>CFBundleAllowMixedLocalizations</key>
... (9 Replies)
Hi,
I need some guidance with understanding this Perl script below. I am not the author of the script and the author has not leave any documentation. I supposed it is meant to be 'easy' if you're a Perl or regex guru. I am having problem understanding what regex to use :confused: The script does... (3 Replies)
Discussion started by: newbie_01
3 Replies
LEARN ABOUT MOJAVE
bytes
bytes(3pm) Perl Programmers Reference Guide bytes(3pm)NAME
bytes - Perl pragma to force byte semantics rather than character semantics
NOTICE
This pragma reflects early attempts to incorporate Unicode into perl and has since been superseded. It breaks encapsulation (i.e. it
exposes the innards of how the perl executable currently happens to store a string), and use of this module for anything other than
debugging purposes is strongly discouraged. If you feel that the functions here within might be useful for your application, this possibly
indicates a mismatch between your mental model of Perl Unicode and the current reality. In that case, you may wish to read some of the perl
Unicode documentation: perluniintro, perlunitut, perlunifaq and perlunicode.
SYNOPSIS
use bytes;
... chr(...); # or bytes::chr
... index(...); # or bytes::index
... length(...); # or bytes::length
... ord(...); # or bytes::ord
... rindex(...); # or bytes::rindex
... substr(...); # or bytes::substr
no bytes;
DESCRIPTION
The "use bytes" pragma disables character semantics for the rest of the lexical scope in which it appears. "no bytes" can be used to
reverse the effect of "use bytes" within the current lexical scope.
Perl normally assumes character semantics in the presence of character data (i.e. data that has come from a source that has been marked as
being of a particular character encoding). When "use bytes" is in effect, the encoding is temporarily ignored, and each string is treated
as a series of bytes.
As an example, when Perl sees "$x = chr(400)", it encodes the character in UTF-8 and stores it in $x. Then it is marked as character data,
so, for instance, "length $x" returns 1. However, in the scope of the "bytes" pragma, $x is treated as a series of bytes - the bytes that
make up the UTF8 encoding - and "length $x" returns 2:
$x = chr(400);
print "Length is ", length $x, "
"; # "Length is 1"
printf "Contents are %vd
", $x; # "Contents are 400"
{
use bytes; # or "require bytes; bytes::length()"
print "Length is ", length $x, "
"; # "Length is 2"
printf "Contents are %vd
", $x; # "Contents are 198.144"
}
chr(), ord(), substr(), index() and rindex() behave similarly.
For more on the implications and differences between character semantics and byte semantics, see perluniintro and perlunicode.
LIMITATIONS
bytes::substr() does not work as an lvalue().
SEE ALSO
perluniintro, perlunicode, utf8
perl v5.18.2 2013-11-04 bytes(3pm)