The following is my code sample:
<?php
echo addcslashes('ABC','\0..\37');
?>
My output is
\A\B\C
As per the documentation, \0...\37 would escape the ASCII values between 0 and 31. But I find that capital alphabets whose ASCII values more than 31, are being escaped here. When i tried the with small letters, it is working correctly.
What should i add to make addcslashes function work for given ASCII characters?
Use double quotes so that \-escapes will work properly:
echo addcslashes('ABC', "\0..\37");
With single quotes '\0..\37' is interpreted as \ + range 0..\ + characters 37.
For example all capital alphabets will be within that range 0..\, which is why they were being escaped.
You need to use double quotes for the $charlist parameter:
echo addcslashes('ABC', "\0..\37");
With single quoted string backslash does not represent a special character sequence.
Also see the manual for double quoted strings.