Hey All,
I'm trying to clean up a variable using sed but It dosn't seem to work. I'm trying to find all the spaces and replace them with "\ " (a slash and a space). For Example "Hello World" should become "Hello\ World". But it does nothing. If I put it directly into the command line it works... (3 Replies)
Hi everyone,
I have a simple question to ask :
In a script that I'm writting, I need to create variables on-the-fly.
For instance, for every iterartion of the following loop a var_X variable should be generated :
#!/bin/ksh
a="1 2 3"
for i in $a
do
var_${i}=$i
echo "${var_$i}"
done
... (1 Reply)
I have run into a wall with my iptables firewall scripting.
I am blocking all of the private side IP addresses on the
WAN interface on systems running NAT. However, if the
system is not running NAT and needs to allow access to
the local LAN on the WAN interface, I need to block all
but one of... (2 Replies)
Hello,
i have another sed question.. I'm trying to do variable substition with sed and i'm running into a problem.
my var1 is a string constructed like this:
filename1 filerev1 filepath1
my var2 is another string constructed like this:
filename2 filerev2 filepath2
when i do... (2 Replies)
Hi,
That might be pretty simple.
How can I generate a variable name and get their value ?
Thanks a lot.
Something like:
>CUSTOMER_NF=26
> object=CUSTOMER
> echo ${object}_NF
CUSTOMER_NF
> echo ${${object}_NF}
ksh: ${${object}_NF}: 0403-011 The specified substitution is... (7 Replies)
file1.ksh
#!/bin/ksh
test5_create="I am a man" # test5 will be dynamic and the value will be passed from command line
a=${1}_create
echo $a # i need the output as "I am a man"
./file1.ksh test5 # i run the script like this
any suggessions guys... (1 Reply)
Hi ,
I have a variable as follows,
Temp=`cat ABC.txt | cut -c5-`
This will yeild a part of the date. say , 200912.
I would like to substitute this variable's value in a filename.
eg: File200912F.zip
when i say File$TempF.zip , it is not substituting.
Any help ?
Thanks in... (2 Replies)
When script is running you only see when some of the commands are not successfull.
Is there a way to see which command are executed and to show the substitution of variables as every line is executed ? (3 Replies)
For example I have variable like below
echo $OUTPUT
/some/path/`uname -n`
when I try to use the variable OUTPUT like below
cd $OUTPUT or cd ${OUTPUT}
I am getting bad substituion error message
$ cd $OUTPUT
ksh: cd: bad substitution
$ cd ${OUTPUT}
ksh: cd: bad substitution
... (1 Reply)
Hi,
I have to write a shell script in which I have to substitute a variable within a variable. For example,
var1=aaa
var2=file.$var1.txt
The output should be,
echo $var2
file.aaa.txt
Can someone please help me in getting this. I tried using eval, but it didnt work. I might be using it... (2 Replies)
Perl::Critic::Policy::ErrorHandling::RequireCheckingRetuUserlContributed PPerl::Critic::Policy::ErrorHandling::RequireCheckingReturnValueOfEval(3)NAME
Perl::Critic::Policy::ErrorHandling::RequireCheckingReturnValueOfEval - You can't depend upon the value of "$@"/"$EVAL_ERROR" to tell
whether an "eval" failed.
AFFILIATION
This Policy is part of the core Perl::Critic distribution.
DESCRIPTION
A common idiom in perl for dealing with possible errors is to use "eval" followed by a check of $@/$EVAL_ERROR:
eval {
...
};
if ($EVAL_ERROR) {
...
}
There's a problem with this: the value of $EVAL_ERROR can change between the end of the "eval" and the "if" statement. The issue is object
destructors:
package Foo;
...
sub DESTROY {
...
eval { ... };
...
}
package main;
eval {
my $foo = Foo->new();
...
};
if ($EVAL_ERROR) {
...
}
Assuming there are no other references to $foo created, when the "eval" block in "main" is exited, "Foo::DESTROY()" will be invoked,
regardless of whether the "eval" finished normally or not. If the "eval" in "main" fails, but the "eval" in "Foo::DESTROY()" succeeds,
then $EVAL_ERROR will be empty by the time that the "if" is executed. Additional issues arise if you depend upon the exact contents of
$EVAL_ERROR and both "eval"s fail, because the messages from both will be concatenated.
Even if there isn't an "eval" directly in the "DESTROY()" method code, it may invoke code that does use "eval" or otherwise affects
$EVAL_ERROR.
The solution is to ensure that, upon normal exit, an "eval" returns a true value and to test that value:
# Constructors are no problem.
my $object = eval { Class->new() };
# To cover the possiblity that an operation may correctly return a
# false value, end the block with "1":
if ( eval { something(); 1 } ) {
...
}
eval {
...
1;
}
or do {
# Error handling here
};
Unfortunately, you can't use the "defined" function to test the result; "eval" returns an empty string on failure.
Various modules have been written to take some of the pain out of properly localizing and checking $@/$EVAL_ERROR. For example:
use Try::Tiny;
try {
...
} catch {
# Error handling here;
# The exception is in $_/$ARG, not $@/$EVAL_ERROR.
}; # Note semicolon.
"But we don't use DESTROY() anywhere in our code!" you say. That may be the case, but do any of the third-party modules you use have them?
What about any you may use in the future or updated versions of the ones you already use?
CONFIGURATION
This Policy is not configurable except for the standard options.
SEE ALSO
See thread on perl5-porters starting here: <http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2008-06/msg00537.html>.
For a nice, easy, non-magical way of properly handling exceptions, see Try::Tiny.
AUTHOR
Elliot Shank "<perl@galumph.com>"
COPYRIGHT
Copyright (c) 2008-2011 Elliot Shank.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. The full text of this license
can be found in the LICENSE file included with this module.
perl v5.16.32014-0Perl::Critic::Policy::ErrorHandling::RequireCheckingReturnValueOfEval(3)