works in ksh, bash, zsh.
The standard shell needs a command like cat
Code:
var=$( cat < /path/to/file )
It is safer to only read one line from the file:
Code:
IFS= read -r var < /path/to/file
And this works in standard-compliant shells.
The IFS= and the -r force a raw read. By default read strips leading and trailing space and continues with the next line if the line ends with a \ character.
i want to insert a variable in the last column of a file, the columns are separated by "|". I want to insert the variable in everyline of the file . (7 Replies)
I have tried
sed '/6/a text_to_inserted' file > newfile
but this inserts test_to_insert at random places in file and i want it in specific location, which is line 6.
can anyone help.... (6 Replies)
Hi all, I am trying to insert couple of lines before first occurance of line3 which occuring after line 5.
So I identified the line 5 line number in the file. Also redirected the all line3 line number to out.txt.
Now I have problem in inserting the line using the variable $rep. Please help me... (2 Replies)
Hey guys ,
i have a variable with the contents ...
NUMBER=4
and a test file with the contents
1248
1213
1214
1278
1200
3045
3444
2130
I want to execute a script that will produce the following output ( based on NUMBER=4) to be ...
create 1248 (1 Reply)
Hi, I want to insert one file into another like this:
file 1:
1
2
3
<!-- #include file="file2" -->
4
5
<!-- #include file="file3" -->
6
with the complete output going to another file. Have seen some solutions to similar problems using sed, but this problem is different because it is... (5 Replies)
Hi I need a bash script that can search through a text file and when it finds 'FSS1206' I need to put a Letter F 100 spaces after the second instance of FSS1206
The format is the same throughout the file I need to repeat this on every time it finds the second 'FSS1206' in the file
I have... (0 Replies)
Hello,
I have the following variables set in my env
echo $MY_XSD_FILE
/home/jak/sample.xsd
echo $MY_INTERVAL_VALUE
4
I want to insert them between the xml tags in my xml file
cat sample.xml
:::::::::::::::
:::::::::::::::
<property name="FILE"></property>
:::::::::::::::::::::::... (2 Replies)
Hi, I'm looking to accomplish the following.
Insert current date into three places/cells within a cvs, every time the bash script is executed.
The cells are column A,B,C row 2. Row 1 is reserved for the headers.
The file name is always orders.csv. These three cells we always have an old... (1 Reply)
I have multiple xml files where i want to update a subnode if the subnode project points to different project or insert a subnode if it doesn't exist using a xmlstarlet or any other command that can be used in a bash script.
I have been able to update the subnode project if it doesn't point to... (1 Reply)
I currently have a loop that reads all .bam files in a directory (wont always be 4 like in this example,
into $id. What I am trying to do, unsucessfully, is create specific new lines in an exsisting command using
each $id. Each new line would be:
--bam ${id} \
Tried
p=$dir... (8 Replies)
Discussion started by: cmccabe
8 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)