Bash Scripting
https://sushant747.gitbooks.io/total-oscp-guide/basics_of_linux.html
This script will iterate over a file and echo out every single line:
#!/bin/bash
for line in $(cat file.txt);do
echo $line
done
Another way of writing is this:
#!/bin/bash
while read p; do
echo $p
done <file.txt
#!/bin/bash
for ((i = 0; i < 10; i++)); do
echo $i
done
Another way to write this is by using the program
seq. Seq is pretty much like range() in python. So it can be used like this:#!/bin/bash
for x in `seq 1 100`; do
echo $x
done
$1 here represent the first argument.
if [ "$1" == "" ]; then
echo "This happens"
fi
#!/bin/bash
if [ "$1" == "" ]; then
echo "This happens"
else
echo "Something else happens"
fi
Command line arguments are represented like this
#!/bin/bash
$1
This is the first command line argument.
If you do a ping-sweep with host the command will take about a second to complete. And if you run that against 255 hosts I will take a long time to complete. To avoid this we can just deamonize every execution to make it faster. We use the
& to daemonize it.#!/bin/bash
for ip in $(cat ips.txt); do
ping -c 1 $ip &
done
It has happened to me several times that I want to input the output of a command into a new command, for example:
I search for a file, find three, and take the last line, which is a path. Now I want to cat that path:
#!/bin/bash
locate 646.c | tail -n 1
This can be done like this:
#!/bin/bash
cat $(locate 646.c | tail -n 1)
Last modified 2yr ago