Both A and B are untouched so B IS NOT the former A. Right?
Yes. This is what i'd expect.
I'd also expect some diagnostic message to be issued (i don't have OS X but i suppose it would be something along the lines of "Error: cannot ....") and the return-code to be non-zero. This is a common trait of UNIX-commands: whenenver they cannot do what is asked they will return a non-zero error code. Try the following:
/etc/hosts is a file supposed to exist, so the return code should be zero, the second file does not exist, so the error code will be presumably 2 (if OS X-ls works the same way as my ls on AIX, the value might differ but it should be non-zero in any case).
i'm using SunOS 5.7 and I know theres a ls option for seeing what kind of files are in a directory. I was wondering if there was a ls option that could see if the files are txt or files that can be opened in vi (1 Reply)
How can I use the 'ps' command to view current sessions but only for a given process/user, with the -u parm?
In older versions of Unix, this used to work, but not in Sun Solaris.
Thanks (4 Replies)
Running HP 11.31 on a HP3600. But when I log in as a user the who command works but if I use an option like "who -m" I get nothing. Any thoughts on what is causing this problem. (11 Replies)
Hi,
what is the meaning of -n option before the grep command ?
grep command searches for the specified string in the file tmp_crontab.txt
but what does -n mean ?
With Regards (1 Reply)
Hi Friends,
I could see following oracle process in the glance command. i see nothing running in the database although. I tried google it but no success. Another team ,which needs all the processes on the server is complaining. Can someone help me what exactly are these sessions/ how to ... (1 Reply)
I am just learning shell scripting and already I found out I have the bad habit of thinking that it is similar to php or c.
I learned some basics and now encountered this problem:
On shell it is possible to type:
$ date --date="2009-10-10 09:08:34"
Sat Oct 10 09:08:34 CEST 2009
... (2 Replies)
Dear all,
I want to execute fsck command,can i execute fsck command without any option
asking for more confidence.
Thanks and Regards
Monoj Das (1 Reply)
Hi folks,
I totally dislike asking questions in forums but this one eats up to much of my time I need to spend on other topics.
I have a shell-script in which I call a terminal.
I want to invoke bash inside the terminal and print a message inside bash with aid of a here document.
See... (7 Replies)
Discussion started by: bluntroller
7 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)