Regex – Looking for a string with regex and delete the whole line

regextextpad

I am trying to find in Textpad a character with regex (for example "#") and if it is found the whole line should be deleted. The # is not at the beginnen of the line nor at the end but somewehre in between and not connected to another word, number or charakter – it stands alone with a whitespace left and right, but of course the rest of the line contains words and numbers.

Example:

My first line
My second line with # hash
My third line# with hash

Result:

My first line
My third line# with hash

How could I accomplish that?

Best Answer

Let's break it down:

^     # Start of line
.*    # any number of characters (except newline)
[ \t] # whitespace (tab or space)
\#    # hashmark
[ \t] # whitespace (tab or space)
.*    # any number of characters (except newline)

or, in a single line: ^.*[ \t]#[ \t].*

Related Solutions

Regex – Find and kill a process in one line using bash and regex

In bash, you should be able to do:

kill $(ps aux | grep '[p]ython csp_build.py' | awk '{print $2}')

Details on its workings are as follows:

The ps gives you the list of all the processes.
The grep filters that based on your search string, [p] is a trick to stop you picking up the actual grep process itself.
The awk just gives you the second field of each line, which is the PID.
The $(x) construct means to execute x then take its output and put it on the command line. The output of that ps pipeline inside that construct above is the list of process IDs so you end up with a command like kill 1234 1122 7654.

Here's a transcript showing it in action:

pax> sleep 3600 &
[1] 2225
pax> sleep 3600 &
[2] 2226
pax> sleep 3600 &
[3] 2227
pax> sleep 3600 &
[4] 2228
pax> sleep 3600 &
[5] 2229
pax> kill $(ps aux | grep '[s]leep' | awk '{print $2}')
[5]+  Terminated              sleep 3600
[1]   Terminated              sleep 3600
[2]   Terminated              sleep 3600
[3]-  Terminated              sleep 3600
[4]+  Terminated              sleep 3600

and you can see it terminating all the sleepers.

Explaining the grep '[p]ython csp_build.py' bit in a bit more detail:

When you do sleep 3600 & followed by ps -ef | grep sleep, you tend to get two processes with sleep in it, the sleep 3600 and the grep sleep (because they both have sleep in them, that's not rocket science).

However, ps -ef | grep '[s]leep' won't create a process with sleep in it, it instead creates grep '[s]leep' and here's the tricky bit: the grep doesn't find it because it's looking for the regular expression "any character from the character class [s] (which is s) followed by leep.

In other words, it's looking for sleep but the grep process is grep '[s]leep' which doesn't have sleep in it.

When I was shown this (by someone here on SO), I immediately started using it because

it's one less process than adding | grep -v grep; and
it's elegant and sneaky, a rare combination :-)

.net – Regex for string not containing multiple specific words

Use a negative look-ahead that asserts the absence of any of the three words somewhere in the input:

^(?!.*(trunk|tags|branches)).*$

I also slightly rearranged your regex to correct minor errors.

Best Answer

Related Solutions

Regex – Find and kill a process in one line using bash and regex

.net – Regex for string not containing multiple specific words

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