Hi,
I have a TEST.dat file. As a clean up process, I have to delete the TEST.dat file if it is empty. Basically, I don't want to delete TEST.dat if it contains anything in it but want to delete TEST.dat if it contains any spaces or nothing in it.
Is there a command to check if the file... (2 Replies)
hi
how can I determine, if a file is empty or not?I am using read line clause.
The script should be like:
while read line
do
if(file is empty) then;
......
done < $blacklist (1 Reply)
I have a program that takes a file in which I use a sed to remove some data that is not needed. If all of the data is removed. I want to grep for that in the file and print that there is no data left in the file. When I use sed, I replace a word with nothing but it still seems to leave a return... (5 Replies)
Hi All,
I have a piece of perl code in which I DON'T want to delete a file rather empty out the contents, here is the code -
if ( unlink("$opt_b") == 1 ) {
print_log( "$opt_b deleted", 1 );
}else {
print_log( "Could not delete $opt_b:$!", 1 );
... (5 Replies)
Hi there,
I'm just starting out with shell scripting and I'm trying to make a test where the script will basically run yum check-update to find out if the server has any available and if it does it e-mails me but if not it will just stop there.
I have it working if there are actually... (7 Replies)
when I run the following command in AIX (bash),
find ./*
I get the following error.
find: bad status-- ./*
Thats becasuse, its an empty directory. The same works, when there the directory is not empty. Even though the find deesnt have to rerun any result.
My full find command would look... (4 Replies)
Discussion started by: deepakwins
4 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)