LinuxQuestions.org - [SOLVED] BASH script

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i want to write a script. i am using centos 6 x64.
basically i want to write a script in which i need to go to home directory of user in every machine. but i dont remember the username of every user. so what is the simbol to use before username. script is something like below. basically i want to enter something in .bashrc file for every user.

Code:

echo "export LD_LIBRARY_PATH=/opt/R-2.15.2/lib:$LD_LIBRARY_PATH" >> /home/$username/.bashrc

The symbol is tild (~)
If you use

Code:

cd ~

You reach into the logged in user's home directory.

If you use

Code:

cat ~/.bashrc

It opens the .bashrc file of every user, you do not have to write the username. It is valid for every user.

Quote:

Originally Posted by bloodstreetboy (Post 5165625)

The symbol is tild (~)
If you use

Code:

cd ~

You reach into the logged in user's home directory.

If you use

Code:

cat ~/.bashrc

It opens the .bashrc file of every user, you do not have to write the username. It is valid for every user.

basically i want to go to user home directory and there is only one directory under /home
could you help me to know how can i achieve this task.

If you are root and you have to go to the user's home directory and if there is only one directory in /home

Code:

#!/bin/bash

dir1=$(ls /home)

cd "/home/$dir1"

You can reach into user's home directory

If you are root and you have to go to the user's home directory and if there are more than one directory in /home

Code:

i=1

dir3=$(ls -1 /home | wc -l )

while [ $i -le $dir3 ]

do

dir2=$(ls -1 /home | tail -n +$i | head -n 1)

cd "/home/$dir2"

## now root is in the user's home directory, write the task here what you want to achive after going into user's directory

## the task should be common for all users because when loop will take its second round, it will be in second user's home directory then third and so on

i=`expr $i + 1`

done

*EDIT jpollard makes a very valid point. You should refer to his post #7 instead of mine.

Not all users necessarily have their home directory in /home. ~ and ~user will require you to know the usernames beforehand. Your best bet is to parse /etc/passwd for users greater than some UID. In my case uid >=1000 and excluding the nobody user. Take for example this entry in /etc/passwd...

Code:

sam:x:1000:1000:Sam,,,:/home/sam:/bin/bash

It is a colon separated value. The first entry is the user name. The third entry is the uid. The sixth entry is the home directory. That's where you should start. A quick awk script prints all users' home directories whom have a uid 1000 or greater and not the nobody user.

Code:

awk 'BEGIN {FS=":"};$3 > 999 && $1 != "nobody" {print $6}' /etc/passwd

You can pipe the output into a while loop and start processing whatever you want to process. You may need to adjust the script for the uid range of your system. Note I corrected your echo statement because I assume you want the literal text to output and not the variable to be replaced.

Code:

#!/bin/bash

awk 'BEGIN {FS=":"};$3 > 999 && $1 != "nobody" {print $6}' /etc/passwd | while read x;do

  echo 'export LD_LIBRARY_PATH="/opt/R-2.15.2/lib:$LD_LIBRARY_PATH"' >> "${x}/.bashrc"

done

You should fully understand the above code before executing it.

If you have multiple users on each machine, you will want to apply this to each user no? So maybe something like:

Code:

list1=$(ls /home)

for i in $list1; do echo "your text" >> $i/.bashrc; done

and don't forget root, if you need it there as well?

Why would you add that to every user?

Put it in the /etc/profile or /etc/bashrc and let everyone get it at once.

Makes it easier to adjust later instead of just accumulating more errors as the system evolves.

Thnx guys for your support.
i was looking exactly same stuff.