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Old 10-12-2018, 02:26 AM   #16
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Originally Posted by fick_manning View Post
i understood that if i put the nine it tells the command that there is what to read from and therfor there are permittion..from whatsapp group
so i could put any number that i want?
I'm sorry I did not understand your first sentence. Yes, you can put whatever number you require in a particular scenario.

Please have a look at that
Old 10-12-2018, 03:32 AM   #17
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As explained by BW-userx, you should really edit your initial post again and *put back your question* because it's really a mess for newcomers of this thread to get what it is all about here...
Old 10-12-2018, 05:10 PM   #18
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From "man grep" in shell:

A regular expression may be followed by one of several repetition operators:
? The preceding item is optional and matched at most once.
* The preceding item will be matched zero or more times.
+ The preceding item will be matched one or more times.
{n} The preceding item is matched exactly n times.
{n,} The preceding item is matched n or more times.
{,m} The preceding item is matched at most m times. This is a GNU extension.
{n,m} The preceding item is matched at least n times, but not more than m times.
The brackets have a slash in front of them to escape them, so the {9} means to match 9 times.

I did a lot of my studying by reading the "man"uals. Several years ago I even printed out a lot of them and have a 2" binder full of man pages.
Old 10-13-2018, 01:04 AM   #19
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There are two types of RE,
BRE (basic regular expression) and ERE (extended regular expression).
grep and sed default to BRE, while egrep (or grep -E) and sed -r and awk and perl and php (and most modern languages) use ERE.
The following is BRE
grep "^[-d][^-]\{9\}"
The [-d] is a character set, a character that can be either - or d
You can also write [d-]
The first character ^ in a character set is a negation of the following, [^-] is a character that is not a -
The \{ \} is a repetion of the previous character, here the character set: here 9 characters that are not a -

Last edited by MadeInGermany; 10-13-2018 at 01:05 AM.
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