09-25-2012
The standard approach would be to use eval, but that needs to be done carefully, since it could introduce security risks..
What OS and version are you using?
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
I was wondering if there is anyway to use the curses library with ksh88. I saw Shell Curses function library which says I can use /usr/local/functions/shellcurses on ksh93 but I am on ksh88. I am on a HP-UX box. (0 Replies)
Discussion started by: IMTheNachoMan
0 Replies
2. Shell Programming and Scripting
Hi all!
Does anybody know how can I check if any UNIX installation has implemented ksh88 or ksh93?
Thanks in advance.
Néstor. (3 Replies)
Discussion started by: Nestor
3 Replies
3. Shell Programming and Scripting
Hello,
ksh88 doesn't support ${var:x:y}.
Any alternatives to get substring ?
thanks
Vilius (2 Replies)
Discussion started by: vilius
2 Replies
4. Shell Programming and Scripting
Hello,
I need ksh88 for my linux system - and I don't want pdksh.
Possible to get original ksh 88 binaries or source ?
(I don't need ksh93 which is available)
thanks
Vilius (1 Reply)
Discussion started by: vilius
1 Replies
5. Shell Programming and Scripting
Hi,
With:
# VALUES="one~two~~~"
# echo $VALUES | awk 'BEGIN {FS="~"} {print NF}'
5
I can determine the number of fields.
How to determine the number of fields with a value ?
In this case 2.
Thanks in advance,
ejdv (6 Replies)
Discussion started by: ejdv
6 Replies
6. Shell Programming and Scripting
Hi I tried the following string comparison script in Ksh88
#!/bin/ksh
str1='aC'
str2='ABC'
if
then
echo "Equal"
else
echo "Not Equal"
fi
Though str1 and str2 are not equal the script output says Equal .
Please correct me
Thanks (2 Replies)
Discussion started by: smile689
2 Replies
7. Shell Programming and Scripting
I'm using Ksh88 .
I've last day files in one directory and current month files in another directory , having the same naming convention.
Now i need to compare these folders size , if there is no change in these files then no action to be performed
else if there is a change then i need to call... (1 Reply)
Discussion started by: smile689
1 Replies
8. Shell Programming and Scripting
Hi I tried the following code to FTP the files from test server to dev
#!/bin/ksh
DST=/home/files
cd $DST
ftp -inv 'test_serv101' << EOF
quote USER test
quote PASS test
# File Path on test server
cd /etc/home/Or_Files
ascii
mget curMonth* $DST
quit
EOF
when i try the above code it... (4 Replies)
Discussion started by: smile689
4 Replies
9. Solaris
Hello,
I want to pick a random element from a list, and created these 2 lines, which work very well in ksh93. Unfortunately, I get this "bad substitution" message in ksh88.
I'm wondering if there's an equivalent to the second line of my script.. or if I have to install ksh93 to make this... (8 Replies)
Discussion started by: gfroute
8 Replies
10. OS X (Apple)
I don't know if anyone is interested but I have been meddling with FFT for the AMIGA.
(Sadly we AMIGAns don't have these luxuries through any scripting language.
Below is a Python snippet that uses the builtin 'cmath' module to work with the lowly
Python 2.0.1 for the AMIGA. It is part of a... (0 Replies)
Discussion started by: wisecracker
0 Replies
LEARN ABOUT CENTOS
perl::critic::policy::errorhandling::requirecheckingreturnvalueo
Perl::Critic::Policy::ErrorHandling::RequireCheckingRetuUserlContributed PPerl::Critic::Policy::ErrorHandling::RequireCheckingReturnValueOfEval(3)
NAME
Perl::Critic::Policy::ErrorHandling::RequireCheckingReturnValueOfEval - You can't depend upon the value of "$@"/"$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 v5.16.3 2014-0Perl::Critic::Policy::ErrorHandling::RequireCheckingReturnValueOfEval(3)