What is the more efficient way to do this (awk only and default FS) ?
$ echo "jefe@alm"|awk '{pos = index($0, "@");printf ("USER: %s\n",substr ($0,1,pos-1))}'
USER: jefe
Thx in advance (2 Replies)
Hi,
My input file is
41;2;xxxx;yyyyy....
41;2;xxxx;yyyyy....
41;2;xxxx;yyyyy....
..
..
I need to change the second field value from 2 to 1. i.e.,
41;1;xxxx;yyyyy....
41;1;xxxx;yyyyy....
41;1;xxxx;yyyyy....
..
..
Thanks in advance. (9 Replies)
Hi,
I have a long string like,
aabab|bcbcbcbbc|defgh|paswd123 dedededede|efef|ghijklmn|paswd234 ghghghghgh|ijijii|klllkkk|paswd345 lmlmlmmm|nononononn|opopopopp|paswd456
This string is devided into one space between substrings. This substrings are,
aabab|bcbcbcbbc|defgh|paswd123... (6 Replies)
why do inode indices starts from 1 unlike array indexes which starts from 0
its a question from "the design of unix operating system" of maurice j bach
id be glad if i get to know the answer quickly
:) (0 Replies)
brothers why inode index starts from 1 unlike array inex which starts from 0
its a question from the design of unix operating system of maurice j.bach
i need to know the answer urgently...someone help please (1 Reply)
Hi All,
I have a file (FileNames.txt) which contains the following data in it.
$ cat FileNames.txt
MYFILE17XXX208Sep191307.csv
MYFILE19XXX208Sep192124.csv
MYFILE20XXX208Sep192418.csv
MYFILE22XXX208Sep193234.csv
MYFILE21XXX208Sep193018.csv
MYFILE24XXX208Sep194053.csv... (5 Replies)
I would like to extract a digit from $0 starting 2,30 to 3,99 or 2.30 to 3.99
Can somebody fix this?
awk --re-interval '{if($0 ~ /{1}{2}/) {print FILENAME, substr($0,index($0,/{1}{2}/) , 4)}}'input
abcdefg sdlfkj 3,29 g. lasdfj
alsdfjasl 2.86 gr. slkjds sldkd
lskdjfsl sdfkj kdjlksj 3,34 g... (4 Replies)
I have a command like this:
listdb ID923 -l |gawk '{if (substr($0,37,1)==1 && NR == 3)print "YES" else if (substr ($0,37,1)==0 && NR == 3) print "NO"}'
This syntax doesn't work. But I was able to get this to work:
listdb ID923 -l |gawk '{if (substr($0,37,1)==1 && NR == 3)print "YES"}'
... (4 Replies)
awk '/^>/{id=$0;next}length>=7 { print id, "\n"$0}' Test.txt
Can I use substr to achieve the same task?
Thanks! (8 Replies)
Discussion started by: Xterra
8 Replies
LEARN ABOUT LINUX
bytes
bytes(3pm) Perl Programmers Reference Guide bytes(3pm)NAME
bytes - Perl pragma to force byte semantics rather than character semantics
NOTICE
This pragma reflects early attempts to incorporate Unicode into perl and has since been superseded. It breaks encapsulation (i.e. it
exposes the innards of how the perl executable currently happens to store a string), and use of this module for anything other than
debugging purposes is strongly discouraged. If you feel that the functions here within might be useful for your application, this possibly
indicates a mismatch between your mental model of Perl Unicode and the current reality. In that case, you may wish to read some of the perl
Unicode documentation: perluniintro, perlunitut, perlunifaq and perlunicode.
SYNOPSIS
use bytes;
... chr(...); # or bytes::chr
... index(...); # or bytes::index
... length(...); # or bytes::length
... ord(...); # or bytes::ord
... rindex(...); # or bytes::rindex
... substr(...); # or bytes::substr
no bytes;
DESCRIPTION
The "use bytes" pragma disables character semantics for the rest of the lexical scope in which it appears. "no bytes" can be used to
reverse the effect of "use bytes" within the current lexical scope.
Perl normally assumes character semantics in the presence of character data (i.e. data that has come from a source that has been marked as
being of a particular character encoding). When "use bytes" is in effect, the encoding is temporarily ignored, and each string is treated
as a series of bytes.
As an example, when Perl sees "$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 v5.12.1 2010-04-26 bytes(3pm)