grep with star symbol

By : Jacques

Date : November 27 2020, 11:01 PM

like below fixes the issue grep requires (at least) two arguments -- what you are searching for, and where you are searching for it. If the second argument is not provided, then it will use stdin instead.
grep text* is waiting for stdin to provide it something to search through.

code :

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Using the star sign in grep

By : Ahmad Dallah

Date : March 29 2020, 07:55 AM

wish of those help The asterisk is just a repetition operator, but you need to tell it what you repeat. /*abc*/ matches a string containing ab and zero or more c's (because the second * is on the c; the first is meaningless because there's nothing for it to repeat). If you want to match anything, you need to say .* -- the dot means any character (within certain guidelines). If you want to just match abc, you could just say grep 'abc' myFile. For your more complex match, you need to use .* -- grep 'abc.*def' myFile will match a string that contains abc followed by def with something optionally in between.
Update based on a comment:

GREP - Regex +(plus) vs. *(star) performance

By : Buso

Date : March 29 2020, 07:55 AM

I hope this helps . Simple question, say I have two regular expressions , These two expressions:

code :

rtmp.*?\b/
rtmp.+?\b/

grep: When should the kleene star(*) match itself?

By : Bill Batey

Date : March 29 2020, 07:55 AM

this one helps. * on its own is an invalid regular expression since there is no previous item to repeat. Your implementation of grep, in this case, interprets it as a literal *. \* is a valid regular expression which matches a *. Your implementation's interpretation of the invalid regular expression * and the valid regular expression \* just happen to be the same.
If you really want to see the difference between * and \*, you should try it on a valid regular expression by adding an item before it. For example, a literal a:

code :

grep 'a*'
grep 'a\*'

Using grep to search a string with a star(*)

By : shugenghuang

Date : March 29 2020, 07:55 AM

this will help grep interprets its pattern as a regular expression, so * means repetition of the previous character (or subexpression). Use grep -F to get rid of this behavior.

grep/egrep the star operator not matching all occurrences

By : Cleon And

Date : March 29 2020, 07:55 AM

seems to work fine Let's take the string AaAa. I want to match the as: , Let's start with this:

code :

$ echo AaAa | grep -o 'a*'
$

2.5.3
=====
Fix the combinations:
 * -i -o
 * --colour -i
 * -o -b
 * -o and zero-width matches
Go through the bug list im my mailbox and fix fixable.
Fix bugs reported with 2.5.2.