Using regular expressions to find img tags without an alt attribute

Question

I am going through a large website (1600+ pages) to make it pass Priority 1 W3C WAI. As a result, things like image tags need to have alt attributes.

What would be the

Answer 1

Building on Mr.Black and Roberts126 answers:

/(]*)(>)/

This will match an img tag anywhere in the code which either has no alt tag or an alt tag which is not followed by ="" or ='' (i.e. invalid alt tags).

Breaking it down:

(          : open capturing group
]*      : match anything following the alt tag up to the closing '>' of the img tag
)          : close capturing group
(>)        : match the closing '>' of the img tag

If your code editor allows search and replace by Regex you can use this in combination with the replace string:

$1 alt=""$3

To find any alt-less img tags and append them with an empty alt tag. This is useful when using spacers or other layout images for HTML emails and the like.