LinuxQuestions.org - Blog Entries

BASH delete line from file

Posted 04-05-2020 at 05:12 PM by karanis

Tags bash

https://www.folkstalk.com/2013/03/se...-examples.html

sed '/^u/d' file
Deletes a line starting with u

karanis

LQ Newbie

Posted in Uncategorized

Views 187 Comments 0 karanis is offline

BASH fork

Posted 04-05-2020 at 05:11 PM by karanis

Tags bash, fork

#!/usr/bin/bash
function_to_fork() {
...
}

function_to_fork &
# ... execution continues in parent process ...

karanis

LQ Newbie

Posted in Uncategorized

Views 212 Comments 0 karanis is offline

nmap Scan Network (better&faster)

Posted 04-05-2020 at 05:10 PM by karanis

Tags bash, net

nmap -sL 192.168.*.* | grep \(1
ip neigh show dev eth1

karanis

LQ Newbie

Posted in Uncategorized

Views 261 Comments 0 karanis is offline

Bash variables storing the output of commands run them at each variable statement, not just at some eventual invocation

Posted 08-10-2016 at 04:30 PM by the dsc (linux-related notes)
Updated 08-10-2016 at 04:33 PM by the dsc

Tags bash

Meaning that a script line such as:

nowstatus=`mpc | grep '#' | cut -d '/' -f1`

Is running mpc, grep and cut at its very statement, not only from an eventual "echo $nowstatus".

Therefore, in scripts that parse differently the same output of a given command, it may be preferable to first store this output in a temporary file, and then parse this file rather than running the same command several times. Such as in the lines added below their equivalent...

the dsc

Member

Posted in Uncategorized

Views 1188 Comments 0 the dsc is offline

N00b method to toggle some verbosity on command for bash scripts

Posted 03-28-2016 at 11:32 PM by the dsc (linux-related notes)
Updated 03-28-2016 at 11:34 PM by the dsc

Tags bash, newbie

Just something I came up with that is probably not how actual programmers/scripters(?) would advise, specially the parameter/flag thing which is beside the point here.

Code:

if [[ $1 == "v" ]] ; then

ver(){
echo $@
}

else

ver(){
:    # ":" is a "do nothing" command
}

fi

a=10

echo normal output

ver verbose output $a

...

the dsc

Member

Posted in Uncategorized

Views 1318 Comments 0 the dsc is offline

Page 3 of 9

Last »

Total Blogs

2,190

Total Entries

8,284

Entries in Last 24 Hours