Regular Expression to match an exact word with any number of spaces before and after it

Question

I want to find an exact word "SUBRECORD" with any number of spaces before and after it. I have tried:

\s*SUBRECORD\s*
[ ]*SUBRECORD[ ]*
(\s)*SUBRECORD(\s)*

but none of them work.

EDIT:

this is the snippet of code that's not working:

QStringList list;
list.append("RECORD \"DEFSTA\" \"Definition des Stations\"");
list.append("  STRING     (2)  \"Version\";");
list.append("  SUBRECORD   (2)  \"Nb de Stations\";");
list.append("    STRING    (30) \"Nom de la Station\";  ");
list.append("    INTEGER   (2)  \"Numero de la Station\";");
list.append("    INTEGER   (4)  \"Extra charge\";");
list.append("    STRING    (5)  \"Mnemonique Station\";");
list.append("    DUMMY     (1)  \"Réserve\";");
list.append("  ENDSUBRECORD;");
list.append("  SIGNATURE        \"Signature\" ;  ");
list.append("ENDRECORD;");

qDebug() << "LAST INDEX OF SUBRECORD:" << list.lastIndexOf(QRegExp("\\s*SUBRECORD\\s*"));

What kind of text are you searching through? [Those regex look correct.](http://regexr.com?376c7) — Nightfirecat, Nov 14 '13 at 02:55
I'm reading a text file line by line and then in a line i want to see if the word "SUBRECORD" exists. a line can look like this: ` SUBRECORD (2) "Nb de Parametres";` — max, Nov 14 '13 at 02:59
if i put `QRegExp(".*SUBRECORD.*")` it returns the index of last appearance of "ENDSUBRECORD;" which would be 8 here. — max, Nov 14 '13 at 03:16
@MoKi your last comment would suggest that your regex is correct but the lastIndexOf is matching on the full line — T.V., Nov 14 '13 at 03:21

bcorso · Accepted Answer · 2013-11-14T04:49:19.267

2

Reason:

lastIndexOf(...) only returns the index if there is an exact match of the entire line. This is from the Qt docs:

int QStringList::lastIndexOf ( const QRegExp & rx, int from = -1 ) const

Returns the index position of the last exact match of rx in the list, searching backward from index position from. If from is -1 (the default), the search starts at the last item. Returns -1 if no item matched.

Because \s*SUBRECORD\s* does not match the line exactly, it does not count it as a match.

Solution:

Instead try: .*\\s+SUBRECORD\\s+.*

The extra .* matches anything extra at the beginning and end.

The \s+ ensures there is at least one space (thanks @T.V.) - also, the extra \ is to escape the backslash when inputting as a QString (thanks @MoKi).

edited Nov 14 '13 at 04:49

answered Nov 14 '13 at 03:23

bcorso

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The solution you suggested would result in the index of `ENDSUBRECORD;` being return. – T.V. Nov 14 '13 at 03:36
Thanks, I changed it to \s+ so that it looks for at least one space character – bcorso Nov 14 '13 at 03:38
1

the correct form would be to use double escape characters that is `.*\\s+SUBRECORD\\s+.*` since Qt accepts `QString` as the `QRegExp` constructor's argument. and yes you are right about it matching the whole line. – max Nov 14 '13 at 04:28

Regular Expression to match an exact word with any number of spaces before and after it

1 Answers1