This should work as long as the output you want to process is whitespace-separated. You can play around with IFS= to use a different separator, but in the general case, it gets rather ugly and cumbersome.
For convenience, I made it so that $var2 will have one leading and one trailing space. Removing or ignoring those is left as an exercise.
The shell is not very good at these things; that's why awk and sed are more or less essential for nearly any moderately complex shell script. (Or use Perl if that helps at all.)
Modern shells have additional facilities, including an array variable type, but this approach works even with Bourne Classic. We are stuck with it, and in fact, we kind of like it, in spite of its oddities and quirks.
In my /etc/profile, my $PATH variable is set as follows:
$PATH =/sbin:/usr/sbin:/usr/bin:/etc
Then how do I add an additional directory to it? say
/export/home/abd/rose
Please advise.
Thanks!
Deepali (3 Replies)
hello,
I have to communicate with a distant station . But Both belong to the same area. So I do not need a gate .
But when I make a traceroute, it indicates that I pass through out a gate.
What can I do to establish a direct connexion between the both.
(with NT ) (1 Reply)
Hello,
I have installed a new program called chimera under the directory /usr/local/bin/chimera.
the executable is under the directory /usr/local/bin/chimera/bin/chimera.e
If i put myself under the latest directiry and I type ./chimera, the program works.
I would like to avoid this and I... (1 Reply)
hi ,
I have a javascript file like this:
function fnValidateId(){
var array_id = new Array("444","7888","6633","555","146562","3333","33332")
var tmp_id = document.form1.id.value;
var num=0;
while(1)
{
if(tmp_id ==... (9 Replies)
Is there a command for finding all files on the system named ".bashrc" that modify the PS1 variable? I'd like to list the full file name(s) and the protection (including the full path). (5 Replies)
Hi,
I have a file that looks something like this (2 columns 4 rows):
eeeeeeeeeeeeeeeeeeeeeeeeeeeee -45
rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr -24
ttttttttttttttttttttttttttttttttttttttttttt -29
uuuuuuuuuuuuuuuuuuuuuuuuuuu -23
How do I get it to look like this:
-45... (3 Replies)
Hello everyone,
I have some data files, with mixed header formats. the sample for the same is:
>ABCD76567.x1
AGTCGATCGTAGTCGTAGCTGT
>ABCD76567.y1
AGTCGATCGTAGTCGTAGCTGT
>ABCD76568.x1 pair_info:898989
AGTCGATCGTAGTCGTAGCTGT
>ABCD76568.y1 pair_info:893489
AGTCGATCGTAGTCGTAGCTGT... (2 Replies)
Hi,
I have a small piece of Makefile script which throw's error on Sun Sparc machine, but works fine with Sun Optron, Linux, AIX machines.
FOO=Naveen
test1:FOO=Dhilip
test1:
@echo FOO is ${FOO}
test2:
@echo Me is ${FOO}
Output on Sun Sparc -
ukhml-v890new-~/test: make test1... (5 Replies)
I have a script that currently runs fine and I need to add or || (or) condition to the if statement and I'm not sure the exact syntax as it relates to the use of brackets.
my current script starts like this:
errLog="/usr/local/website-logs/error.log"
apacheRestart="service httpd restart"... (3 Replies)
Hello,
I have a filename that looks like this:
ABC_96_20141031_041133.232468
I need to shorten only the "_2014" part of the filename to simply "_14" so the filename looks like:
ABC_96_141031_041133.232468
I have to do a search for this string because there are hundreds of files and... (17 Replies)
Discussion started by: bbbngowc
17 Replies
LEARN ABOUT PHP
create_function
CREATE_FUNCTION(3) 1 CREATE_FUNCTION(3)create_function - Create an anonymous (lambda-style) functionSYNOPSIS
string create_function (string $args, string $code)
DESCRIPTION
Creates an anonymous function from the parameters passed, and returns a unique name for it.
Caution
This function internally performs an eval(3) and as such has the same security issues as eval(3). Additionally it has bad perfor-
mance and memory usage characteristics.
If you are using PHP 5.3.0 or newer a native anonymous function should be used instead.
PARAMETERS
Usually these parameters will be passed as single quote delimited strings. The reason for using single quoted strings, is to protect the
variable names from parsing, otherwise, if you use double quotes there will be a need to escape the variable names, e.g. $avar.
o $args
- The function arguments.
o $code
- The function code.
RETURN VALUES
Returns a unique function name as a string, or FALSE on error.
EXAMPLES
Example #1
Creating an anonymous function with create_function(3)
You can use this function, to (for example) create a function from information gathered at run time:
<?php
$newfunc = create_function('$a,$b', 'return "ln($a) + ln($b) = " . log($a * $b);');
echo "New anonymous function: $newfunc
";
echo $newfunc(2, M_E) . "
";
// outputs
// New anonymous function: lambda_1
// ln(2) + ln(2.718281828459) = 1.6931471805599
?>
Or, perhaps to have general handler function that can apply a set of operations to a list of parameters:
Example #2
Making a general processing function with create_function(3)
<?php
function process($var1, $var2, $farr)
{
foreach ($farr as $f) {
echo $f($var1, $var2) . "
";
}
}
// create a bunch of math functions
$f1 = 'if ($a >=0) {return "b*a^2 = ".$b*sqrt($a);} else {return false;}';
$f2 = "return "min(b^2+a, a^2,b) = ".min($a*$a+$b,$b*$b+$a);";
$f3 = 'if ($a > 0 && $b != 0) {return "ln(a)/b = ".log($a)/$b; } else { return false; }';
$farr = array(
create_function('$x,$y', 'return "some trig: ".(sin($x) + $x*cos($y));'),
create_function('$x,$y', 'return "a hypotenuse: ".sqrt($x*$x + $y*$y);'),
create_function('$a,$b', $f1),
create_function('$a,$b', $f2),
create_function('$a,$b', $f3)
);
echo "
Using the first array of anonymous functions
";
echo "parameters: 2.3445, M_PI
";
process(2.3445, M_PI, $farr);
// now make a bunch of string processing functions
$garr = array(
create_function('$b,$a', 'if (strncmp($a, $b, 3) == 0) return "** "$a" '.
'and "$b"
** Look the same to me! (looking at the first 3 chars)";'),
create_function('$a,$b', '; return "CRCs: " . crc32($a) . ", ".crc32($b);'),
create_function('$a,$b', '; return "similar(a,b) = " . similar_text($a, $b, &$p) . "($p%)";')
);
echo "
Using the second array of anonymous functions
";
process("Twas brilling and the slithy toves", "Twas the night", $garr);
?>
The above example will output:
Using the first array of anonymous functions
parameters: 2.3445, M_PI
some trig: -1.6291725057799
a hypotenuse: 3.9199852871011
b*a^2 = 4.8103313314525
min(b^2+a, a^2,b) = 8.6382729035898
ln(a)/b = 0.27122299212594
Using the second array of anonymous functions
** "Twas the night" and "Twas brilling and the slithy toves"
** Look the same to me! (looking at the first 3 chars)
CRCs: -725381282, 342550513
similar(a,b) = 11(45.833333333333%)
But perhaps the most common use for of lambda-style (anonymous) functions is to create callback functions, for example when using
array_walk(3) or usort(3)
Example #3
Using anonymous functions as callback functions
<?php
$av = array("the ", "a ", "that ", "this ");
array_walk($av, create_function('&$v,$k', '$v = $v . "mango";'));
print_r($av);
?>
The above example will output:
Array
(
[0] => the mango
[1] => a mango
[2] => that mango
[3] => this mango
)
an array of strings ordered from shorter to longer
<?php
$sv = array("small", "larger", "a big string", "it is a string thing");
print_r($sv);
?>
The above example will output:
Array
(
[0] => small
[1] => larger
[2] => a big string
[3] => it is a string thing
)
sort it from longer to shorter
<?php
usort($sv, create_function('$a,$b','return strlen($b) - strlen($a);'));
print_r($sv);
?>
The above example will output:
Array
(
[0] => it is a string thing
[1] => a big string
[2] => larger
[3] => small
)
SEE ALSO
Anonymous functions.
PHP Documentation Group CREATE_FUNCTION(3)