I have this insane distrust of compilers and interpreters.
So I do what could be called naive coding in most langauages that I know well enough because of this distrust.
This is one example of my naive code and IS actually inside AudioScope.sh.
Derivatives of this have never failed under normal conditions on the langauges I have used so it seems idiot proof.
Would professionals like yourselvs consider this puerile coding?
That's just about the most difficult way possible to solve the problem. I only resort to it when the language features just can't handle it (i.e. needing to build a recursive parser from scratch).
When you find yourself doing this for trivial things, you're definitely overthinking it. Try inverting the problem. What if you looked for exactly one non-numeric character? You only need to find one to prove the string's bad, and if you can't... fait accompli.
One way:
This is portable across all bourne shells. In BASH, you could reduce it to a single statement.
I apologise because I had pasted this question in the newbies forum first (because i am a bit of a newbie) but thought it might be better suited in here
if i have to sepearate parameters can I use this syntax especially the or part (||) and is this correct
if (6 Replies)
I would like to start coding on my mac, but I'm getting an error when I attempt to execute my script
-bash : testscript: command not found
I have verified that the #! line points to the correct directory.
If you have some insight it would be greatly appreciated!
- D (1 Reply)
Hi All,
I am new to pro*C. I have a select statement as
select a.ename,a.sal,a.empno from emp where &n=(select count(distinct(b.sal)) from emp b where a.sal<=b.sal
for this query I have to write a pro*C program. So can you please send me the complete code. Then I will foloow the same... (1 Reply)
Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!
1. The problem statement, all variables and given/known data:
I have to write a program in Unix to do the following.Given a phrase like george hates john, by... (0 Replies)
HI,
Can some one guide me how to make changes to the script below so that it can load the history of a program to IT server ?
Format of data:
YYYYMMDD065959.dsk.log
YYYYMMDD235959.dsk.log
currently both are loaded together. Need to separate them as above format.
Thanks in advance.
... (1 Reply)
HI,
Can some one guide me how to make changes to the script below so that it can load the history of a program to IT server ?
Format of data:
YYYYMMDD065959.dsk.log
YYYYMMDD235959.dsk.log
currently both are loaded together. Need to separate them as above format.
Thanks in advance.
... (2 Replies)
My company has an in house instant messaging system (like WhatsApp) where users can communicate with each other. I currently have code to email me certain items from my Sparc machine running SunOS 5.10. I want what I am emailing myself to now instant message me. The team that created the messenger... (5 Replies)
Discussion started by: shorty
5 Replies
LEARN ABOUT PHP
eval
EVAL(3) 1 EVAL(3)eval - Evaluate a string as PHP codeSYNOPSIS
mixed eval (string $code)
DESCRIPTION
Evaluates the given $code as PHP.
Caution
The eval(3) language construct is very dangerous because it allows execution of arbitrary PHP code. Its use thus is discouraged.
If you have carefully verified that there is no other option than to use this construct, pay special attention not to pass any user
provided data into it without properly validating it beforehand.
PARAMETERS
o $code
- Valid PHP code to be evaluated. The code mustn't be wrapped in opening and closing PHP tags, i.e. 'echo "Hi!";' must be passed
instead of '<? echo "Hi!"; >'. It is still possible to leave and reenter PHP mode though using the appropriate PHP tags, e.g.
'echo "In PHP mode!"; ?>In HTML mode!<? echo "Back in PHP mode!";'. Apart from that the passed code must be valid PHP. This
includes that all statements must be properly terminated using a semicolon. 'echo "Hi!"' for example will cause a parse error,
whereas 'echo "Hi!";' will work. A return statement will immediately terminate the evaluation of the code. The code will be exe-
cuted in the scope of the code calling eval(3). Thus any variables defined or changed in the eval(3) call will remain visible
after it terminates.
RETURN VALUES eval(3) returns NULL unless return is called in the evaluated code, in which case the value passed to return is returned. If there is a
parse error in the evaluated code, eval(3) returns FALSE and execution of the following code continues normally. It is not possible to
catch a parse error in eval(3) using set_error_handler(3).
EXAMPLES
Example #1
eval(3) example - simple text merge
<?php
$string = 'cup';
$name = 'coffee';
$str = 'This is a $string with my $name in it.';
echo $str. "
";
eval("$str = "$str";");
echo $str. "
";
?>
The above example will output:
This is a $string with my $name in it.
This is a cup with my coffee in it.
NOTES
Note
Because this is a language construct and not a function, it cannot be called using variable functions.
Tip
As with anything that outputs its result directly to the browser, the output-control functions can be used to capture the output of
this function, and save it in a string (for example).
Note
In case of a fatal error in the evaluated code, the whole script exits.
SEE ALSO call_user_func(3).
PHP Documentation Group EVAL(3)