Hi,
i want to check if a variable var1 is not a or b or c
pseudo code:
If NOT (var1 = a or var1 = b or var1 = c)
then
...
fi
I want to use POSIX complaint Korn shell, and for string comparison
For the following code, logical.sh
I gave execute permissions to the script, however it only seems to run good when run by 'sh ' and not by the script itself.
We run all our jobs without specifying 'sh ' ahead
$ chmod 777 logical.sh
$ logical.sh
Var : j
./logical.sh[3]: syntax error at line 6 : `}' unexpected
$ sh logical.sh
Var : j
var not in the list
Var : b
var in the list
$
Where am i going wrong?
Is it necessary to enclose the variable in double quotes but not the literals on the other side of comparison operator?
Hi:confused:,
I have a file that contains :
+-----------------------------------------------------------------------------+
LABEL: super1_fix
EFIX FILES: 1
ABSTRACT: epkg for touch command
PRE-REQUISITES: no
PACKAGER VERSION: 7
REBOOT REQUIRED: no
BUILD BOOT... (4 Replies)
I'm would to create a script that would give me the results below.
Please note the spaces in the log file are actually commas(",".)
Log file Data
0:00 21:15 899 43 31 12 25.39
0:00 21:20 736 34 19 15 35.39
0:00 21:20 776 41 28 13 ... (3 Replies)
Please tell me how to nest logical expressions in bash. I would like to nest logical expressions for arguments of the "test" command on bash.
The following pseudo-code shows my intention.
// pseudo code
if (exp1 AND (exp2 OR exp3))
{
Output true;
}
else
{
Output false;
}
... (11 Replies)
Hello all. This is my first post/question on this site.
I’m a new Systems Analyst with previous experience with BASH. Although now I'm using AIX, and I’m trying to get a feel for the Korn shell (for those of you that don’t know AIX only uses the KORN shell).
I hope I put this into the correct... (10 Replies)
I have code as follows to perform some validations on C++ and Javascript files:
if || || ; then
However, when I want to add other extensions as well, say "py" or "sql", then the repeated OR starts to look contrived. I know I can use the -o operator to abbreviate the code a little bit, but... (14 Replies)
The POSIX shell standard grammar rules are at
Shell Command Language
I am trying to understand Rule 7 and I don't. I think there may be some mistakes there. I am not complaining about the standard; rather, I am concerned that my perception is wrong, and I don't understand something important.... (3 Replies)
Hi all...
This is more of a concensus question than help...
As many of you know I am experimenting with the limitations of Pure POSIX shell scripting.
Q: Is the directory /bin considered part of the Pure POSIX shell or must I stick entirely with the builtins only?
The reason is I... (2 Replies)
Hi all,
I am learning POSIX shell programming, and the book I read, uses the let command for integer arithmetic.
I have downloaded and use the shellcheck program on Linux.
This programs says:
In POSIX sh, 'let' is undefined.
See the screenshot attached.
What is the POSIX... (1 Reply)
Hi all...
This is just a fun project to see if it is possible to get a square root of a positive integer from 1 to 9200000 to 6 decimal places on a 64 bit architecture machine.
It is coded around dash and the results show the values from 0 to 10000.
Complex numbers can easily be catered for by... (3 Replies)
Hi all...
Apologies for any typos, etc...
This took a while but it didn't beat me...
Although there are many methods of generating random numbers in a POSIX shell this uses integer maths and a simple C source to create an executable to get epoch to microseconds accuracy if it is needed. I take... (8 Replies)
Discussion started by: wisecracker
8 Replies
LEARN ABOUT PHP
debug_zval_dump
DEBUG_ZVAL_DUMP(3) 1 DEBUG_ZVAL_DUMP(3)debug_zval_dump - Dumps a string representation of an internal zend value to outputSYNOPSIS
void debug_zval_dump (mixed $variable, [mixed $...])
DESCRIPTION
Dumps a string representation of an internal zend value to output.
PARAMETERS
o $variable
- The variable being evaluated.
RETURN VALUES
No value is returned.
EXAMPLES
Example #1
debug_zval_dump(3) example
<?php
$var1 = 'Hello World';
$var2 = '';
$var2 =& $var1;
debug_zval_dump(&$var1);
?>
The above example will output:
&string(11) "Hello World" refcount(3)
Note
Beware the refcount
The refcount value returned by this function is non-obvious in certain circumstances. For example, a developer might expect the
above example to indicate a refcount of 2. The third reference is created when actually calling debug_zval_dump(3).
This behavior is further compounded when a variable is not passed to debug_zval_dump(3) by reference. To illustrate, consider a
slightly modified version of the above example:
Example #2
<?php
$var1 = 'Hello World';
$var2 = '';
$var2 =& $var1;
debug_zval_dump($var1); // not passed by reference, this time
?>
The above example will output:
string(11) "Hello World" refcount(1)
Why refcount(1)? Because a copy of $var1 is being made, when the function is called.
This function becomes even more confusing when a variable with a refcount of 1 is passed (by copy/value):
Example #3
<?php
$var1 = 'Hello World';
debug_zval_dump($var1);
?>
The above example will output:
string(11) "Hello World" refcount(2)
A refcount of 2, here, is extremely non-obvious. Especially considering the above examples. So what's happening?
When a variable has a single reference (as did $var1 before it was used as an argument to debug_zval_dump(3)), PHP's engine opti-
mizes the manner in which it is passed to a function. Internally, PHP treats $var1 like a reference (in that the refcount is
increased for the scope of this function), with the caveat that if the passed reference happens to be written to, a copy is made,
but only at the moment of writing. This is known as "copy on write."
So, if debug_zval_dump(3) happened to write to its sole parameter (and it doesn't), then a copy would be made. Until then, the
parameter remains a reference, causing the refcount to be incremented to 2 for the scope of the function call.
SEE ALSO var_dump(3), debug_backtrace(3), References Explained, References Explained (by Derick Rethans).
PHP Documentation Group DEBUG_ZVAL_DUMP(3)