Regexp matching spaces in words

Question

I am looking for a regular expression for replacing words written like "word", "overf low" to "word" and "overflow", respectively, all over the input string (including at the beginning and the end).

I'm using PHP & preg_replace. And need to detect those words before splitting string by space and further filtering. Any combinations for the time gives no due result.

Thanks in advance!

Answer 1

this one is hard because: what is a word? what is a part of a word?

What is different between in cr e di ble and it is a dog ?

For that to work with regex you need to set rules, for example:

• How many whitespaces can be between words, and between word parts?
• How long are the parts a word can be divided in?
• Are ALL the words in the string divided in parts?

If you can't be sure of any of those rules then you can't write a regex that will solve the problem. Comparing the words to a dictionary to know if they are valid or not should prove more useful.

Answer 2

$ string = "w o r d", "o v e r f low"
$ echo 'word w o r d' | sed '/\([^ ][^ ]\)[ ]/s::\1\n:g ' | sed '/[ ]\([^ ][^ ]\)/s::\n\1:g' | sed ':r /\([^ ]\)[ ]/s::\1: ; tr' | sed 'H; ${x;/\n/s:: :g;sc[ ]cc;p};d'