Regex match until first instance of certain character

Question

I am trying to match a url up until a special character however the regex I am using is match the last instance when I need it to stop after the first instance. What am I doing wrong?!

.+?(?=\")

To match everything until first "

However my result is below:

Answer 1

You added the " into the consuming part of the pattern, remove it.

^.+?(?=\")

Or, if you need to match any chars including line breaks, use either

(?s)^.+?(?=\")
^[\w\W]+?(?=\")

See demo. Here, ^ matches start of string, .+? matches any 1+ chars, as few as possible, up to the first " excluding it from the match because the "` is a part of the lookahead (a zero-width assertion).

In the two other regexps, (?s) makes the dot match across lines, and [\w\W] is a work-around construct that matches any char if the (s) (or its /s form) is not supported.

Best is to use a negated character class:

^[^"]+

See another demo. Here, ^[^"]+ matches 1+ chars other than " (see [^"]+) from the start of a string (^).