python (12.9k questions)

javascript (9.2k questions)

reactjs (4.7k questions)

java (4.2k questions)

java (4.2k questions)

c# (3.5k questions)

c# (3.5k questions)

html (3.3k questions)

Questions - grep

Removing array entries from lastlog command bash

I am running a command in a script which saves usernames in an array and I was wondering if there is a simple solution to removing these usernames during a run of the lastlog command. I was thinking o...
test-img

Nixbest

arrays

linux

bash

grep

Votes: 0

Answers: 1

Latest Answer

To extend your idea, you could put the list of users into a file and do a ... | grep -vwFf excluded_users.txt | ..... Perhaps a more robust way to remove the users would be to do it in your awk comman...
test-img

user1934428

how-to save result of a command in an if statement to a text file

I need to do something like: while true do if ss --tcp --processes | grep 53501 ; then <save result to /tmp/cmd.out> ; fi done
test-img

user11236651

linux

bash

loops

grep

Votes: 0

Answers: 2

Latest Answer

It's inherently impossible to do exactly this, because a command (or pipeline of commands) produces output as it runs, but doesn't produce an exit status (success/failure) until it's finished running;...
test-img

Gordon Davisson

Count the number of times a substring appears in a file and place it in a new column

Question: I have 2 files, file 1 is a TSV (BED) file that has 23 base-pair sequences in column 7, for example: 1 779692 779715 Sample_3 + 1 ATGGTGCTTTGTTATGGCAGCTC 1 783462 783485 Sample_4 - 1 ATGA...
test-img

KLM117

string

awk

grep

substring

bioinformatics

Votes: 0

Answers: 3

Latest Answer

I'd reach for a programming language like Perl. #!/usr/bin/perl use warnings; use strict; my ($fasta_file, $bed_file) = @ARGV; open my $fasta, '<', $fasta_file or die "$fasta_file: $!"; ...
test-img

choroba

Logic for implementing GNU&#39;s grep -A -B -C flag

I am trying to implement the logic behind grep's -A -B -C flags. To understand how things work, I have cloned the grep C code and looked into it too. But I am not good with C so I am finding it very d...
test-img

Raaz

algorithm

grep

Votes: 0

Answers: 2

Latest Answer

As a start I'd keep a buffer that holds the last A lines read (or C, depending on what has been specified). This buffer has size 1 by default. As soon as grep finds the pattern it is searching for, it...
test-img

Ronald

Posts

Questions

Blogs

Jobs