Firstly, by opening the file for read and write at the same time you are likely to simply zero it. You are better to output to a new file, or use sed or perl inline editting.
# export bulksize=6.10
# perl -pi -e 'if ($. == 4) { s/\=.*/= $ENV{bulksize},/ };' run_example
# cat run_example
celldm(1) = 6.00,
celldm(1) = 6.00,
celldm(1) = 6.00,
celldm(1) = 6.10,
celldm(1) = 6.00,
Will change line 4 in place (didn't want to make a 187 line file:-) Just change the 4 to 187 for line 187.
Hi,
I'm trying following:echo "test line XA24433 test" | sed 's/.*X\(.*\)/X\1/'
XA24433 test While I want the output as: XA24433
I want to grab the words starting with letter X till the next space, this word can be anywhere in the line. (9 Replies)
Hi!
I'm trying to write a regexp but I have no luck...
I have a string like this:
param1=sometext¶m2=hello¶m3=bye
Also, the string can be simply:
param2=hello
I want to return the value of param2: "hello".
How can I do this?
Thanks. (3 Replies)
Hi
I need to get text that are within ""
For example
File:
asdasd "test test2" sadasds asdda asdasd "demo demo2"
Output:
test test2 demo demo2
Any help is good
Thank you (12 Replies)
please consider this:
echo "11111*X*005010X279~ST*270*1111111*005010X279~BHT*0011*11" | sed 's/.*\(005010X(\d)(\d)(\d)*\).*$/\1/'i'm searching for first occurrence of 005010X while leaving rest of characters out.
:confused:
any tips? thnx in advance guys. (7 Replies)
Hi ,
I am learing sed
echo abc 123 def 456 | sed 's|\(*\) \(*\)|\1|'
is returning abc def 456
i was hoping abc def "\1" should only print the occurence of the first pattern
but according to my understanding it is just removing the first occurence of the second pattern... (7 Replies)
Hi all,
How am I read a file, find the match regular expression and overwrite to the same files.
open DESTINATION_FILE, "<tmptravl.dat" or die "tmptravl.dat";
open NEW_DESTINATION_FILE, ">new_tmptravl.dat" or die "new_tmptravl.dat";
while (<DESTINATION_FILE>)
{
# print... (1 Reply)
Hi all,
I want to get a substring from a string based on given delimiter, for example:
str="foo|bar|baz" with delimiter "|",
I want to get one substring at each time with the order number the substring in the whole string,
given 1 to get "foo",
given 2 to get "bar",
given 3 to get "baz",
I... (2 Replies)
Hello All,
I'm trying to extract the lines between two consecutive elements of an array from a file.
My array looks like:
problem_arr=(PRS111 PRS213 PRS234)
j=0
while } ]
do
k=`expr $j + 1`
sed -n "/${problem_arr}/,/${problem_arr}/p" problemid.txt
---some operation goes... (11 Replies)
I am learning SED and just following the shell scripting book, i have trouble understanding the grep and sed statement,
Question : 1
__________
/opt/oracle/work/antony>cat teledir.txt
jai sharma 25853670
chanchal singhvi 9831545629
anil aggarwal 9830263298
shyam saksena 23217847
lalit... (7 Replies)
Discussion started by: Antony Ankrose
7 Replies
LEARN ABOUT DEBIAN
devel::refcount
Devel::Refcount(3pm) User Contributed Perl Documentation Devel::Refcount(3pm)NAME
"Devel::Refcount" - obtain the REFCNT value of a referent
SYNOPSIS
use Devel::Refcount qw( refcount );
my $anon = [];
print "Anon ARRAY $anon has " . refcount($anon) . " reference
";
my $otherref = $anon;
print "Anon ARRAY $anon now has " . refcount($anon) . " references
";
DESCRIPTION
This module provides a single function which obtains the reference count of the object being pointed to by the passed reference value.
FUNCTIONS
$count = refcount($ref)
Returns the reference count of the object being pointed to by $ref.
COMPARISON WITH SvREFCNT
This function differs from "Devel::Peek::SvREFCNT" in that SvREFCNT() gives the reference count of the SV object itself that it is passed,
whereas refcount() gives the count of the object being pointed to. This allows it to give the count of any referent (i.e. ARRAY, HASH,
CODE, GLOB and Regexp types) as well.
Consider the following example program:
use Devel::Peek qw( SvREFCNT );
use Devel::Refcount qw( refcount );
sub printcount
{
my $name = shift;
printf "%30s has SvREFCNT=%d, refcount=%d
",
$name, SvREFCNT($_[0]), refcount($_[0]);
}
my $var = [];
printcount 'Initially, $var', $var;
my $othervar = $var;
printcount 'Before CODE ref, $var', $var;
printcount '$othervar', $othervar;
my $code = sub { undef $var };
printcount 'After CODE ref, $var', $var;
printcount '$othervar', $othervar;
This produces the output
Initially, $var has SvREFCNT=1, refcount=1
Before CODE ref, $var has SvREFCNT=1, refcount=2
$othervar has SvREFCNT=1, refcount=2
After CODE ref, $var has SvREFCNT=2, refcount=2
$othervar has SvREFCNT=1, refcount=2
Here, we see that SvREFCNT() counts the number of references to the SV object passed in as the scalar value - the $var or $othervar
respectively, whereas refcount() counts the number of reference values that point to the referent object - the anonymous ARRAY in this
case.
Before the CODE reference is constructed, both $var and $othervar have SvREFCNT() of 1, as they exist only in the current lexical pad. The
anonymous ARRAY has a refcount() of 2, because both $var and $othervar store a reference to it.
After the CODE reference is constructed, the $var variable now has an SvREFCNT() of 2, because it also appears in the lexical pad for the
new anonymous CODE block.
PURE-PERL FALLBACK
An XS implementation of this function is provided, and is used by default. If the XS library cannot be loaded, a fallback implementation in
pure perl using the "B" module is used instead. This will behave identically, but is much slower.
Rate pp xs
pp 225985/s -- -66%
xs 669570/s 196% --
SEE ALSO
o Test::Refcount - assert reference counts on objects
AUTHOR
Paul Evans <leonerd@leonerd.org.uk>
perl v5.14.2 2011-11-15 Devel::Refcount(3pm)