regexp: only strings without given end string

I try to use regexp to extract strings with certain conditions within a cell array.

My conditions are:

1. String starts with one of severeal given strings (e.g. 'abc', 'def' )
2. There can be several substrings starting with '_' following the substring defined in 1
3. The string must not end with '_std'

Example:

header = {'abc', 'abc_b1', 'abc_b1_std', 'abc_b1_b2', 'abc_b1_b2_std', 'def_b1', 'def_b1_std', 'bcd'};

I'd like to extract:

'abc', 'abc_b1', 'abc_b1_b2', 'def_b1'

I tried the following

res = regexp( header, ['^(abc|def)(_.*)*'] );

but I don't know how to exclude the '_std' at the end.

Any ideas?

( I use MATLAB R2015b)

Answer 1

[Jyotish Robin]

Hi Jette!

Your approach seems right to me in taking into consideration the first two of your requirements. Now, to extend it to exclude the '_std' at the end, you can make use of Lookaround Assertions.

To be specific,

>>res= regexp( header, ['^(abc|def)(_.*)*(?<!std)$'], 'match' )

seems like the required command you need to use.

Hope this helps!

Thanks,

Jyotish