RegEx - Split Update Statement into back references

[spangeman]

Hi All

I'm just starting to learn regular expressions using perl and am trying to write one to replace update statements in a text file using perl. The following seems to work fine:-

UPDATE (.+) SET (.+) =(.+).WHERE (.+) = (.+)

It allows me the back reference the table and column elements of the statements.

However I am aware from reading several tutorials that .+ is bad form as it is greedy and is open to unitended matches e.g. if another <SPACE>SET appeared in 1 line. The tutorials recommend using more precise mathces rather than using the DOT.

How can I do that in this instance?

Many Thanks
Spangeman

 

[MillerH]

Two ways:
[ol]
[li]Use more specific character classes. The any character "." is too general for most situations. Instead use something like \w for word characters or even \S for any non-space characters.[/li]
[li]Use non-greedy matching by adding a ? to your quantifier. Ie "\S+?".[/li]
[/ol]

- Miller

 

[133tcamel]

not 100% sure but you can try using \s*(\w+)\s* instead of .+ in your statement

---
cheers!
san

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