9 added multibyte version
source | link

PHP, 26 84 80 78 62 63 bytes

<?=strrev($s=strtolower(preg_replace("#\W#","",$argv[1])))==$s;

takes input from first command line argument; prints 1 for truthy, empty string for falsy.


I18n is a littly expansive, as there is no multibyte alternative for strrev (110 bytes; run with -r):

preg_match_all("#.#us",$s=strtolower(preg_replace("#\W#u","",$argv[1])),$m);echo$s==join(array_reverse($m[0]);

utf8_strrev blatantly stolen from the PHP manual. You might also want to take a look at this blog post.

PHP, 26 84 80 78 62 63 bytes

<?=strrev($s=strtolower(preg_replace("#\W#","",$argv[1])))==$s;

takes input from first command line argument; prints 1 for truthy, empty string for falsy.

PHP, 26 84 80 78 62 63 bytes

<?=strrev($s=strtolower(preg_replace("#\W#","",$argv[1])))==$s;

takes input from first command line argument; prints 1 for truthy, empty string for falsy.


I18n is a littly expansive, as there is no multibyte alternative for strrev (110 bytes; run with -r):

preg_match_all("#.#us",$s=strtolower(preg_replace("#\W#u","",$argv[1])),$m);echo$s==join(array_reverse($m[0]);

utf8_strrev blatantly stolen from the PHP manual. You might also want to take a look at this blog post.

8 deleted 15 characters in body
source | link

PHP, 26 84 80 78 62 63 bytes

<?=strrev($s=strtolower(preg_replace("#\W#","",$argv[1])))==$s;

takes input from first command line argument; prints 1 for truthy, empty string for falsy. Run with -r.

PHP, 26 84 80 78 62 63 bytes

<?=strrev($s=strtolower(preg_replace("#\W#","",$argv[1])))==$s;

takes input from first command line argument; prints 1 for truthy, empty string for falsy. Run with -r.

PHP, 26 84 80 78 62 63 bytes

<?=strrev($s=strtolower(preg_replace("#\W#","",$argv[1])))==$s;

takes input from first command line argument; prints 1 for truthy, empty string for falsy.

7 $argn does not allow linebreaks (+1 byte)
source | link

PHP, 26 84 80 78 62 6263 bytes

echo strrev<?=strrev($s=strtolower(preg_replace("#\W#","",$argn$argv[1])))==$s;

takes input from STDIN;first command line argument; prints 1 for truthy, empty string for falsy. Run with -Rr.

PHP, 26 84 80 78 62 bytes

echo strrev($s=strtolower(preg_replace("#\W#","",$argn)))==$s;

takes input from STDIN; prints 1 for truthy, empty string for falsy. Run with -R.

PHP, 26 84 80 78 62 63 bytes

<?=strrev($s=strtolower(preg_replace("#\W#","",$argv[1])))==$s;

takes input from first command line argument; prints 1 for truthy, empty string for falsy. Run with -r.

6 back from looping to strrev(strtolower()), (-16 bytes)
source | link
5 reduced back to one version, golfed 2 bytes
source | link
4 added fourth and fifth version
source | link
3 replaced `strtolower` with bit fiddlings. (-4 bytes) added `-n` flag to mute notices.
source | link
2 matched the spec
source | link
1
source | link