Bash Examples

This tutorial was written for those who wish to get involved in Linux environment. This tutorial will be updated from time to time.

• Show where you are Solution

  bash-2.03$ pwd tmp bash-2.03$ export PS1='[\u@\h \w]$ ' [jp@solaris8 /tmp]$

• Need to find and run a particular command under bash Solution

  $ type which which is hashed (/usr/bin/which) $ type ls ls is aliased to 'ls -F -h' $ type -a ls ls is aliased to 'ls -F -h' ls is /bin/ls $apropos music cms (4) - Creative Music System device driver $ apropos music cms (4) - Creative Music System device driver $ locate apropos /usr/bin/apropos ../../../

• Produce some output without the default newline that echo provides Solution

  $ printf "%s %s" next prompt next prompt$ or $ echo -n prompt prompt$

• Saving output from a command

  $ echo fill it up fill it up $ echo fill it up > file.txt $ $ cat file.txt fill it up $

• Saving out from the ls command Solution

  $ ls /tmp/save.out $ cat /tmp/save.out a.out b.out or $ ls -C /tmp/save.out $ cat /tmp/save.out a.out b.out

• Redirect output and error messages to different files

$ myprogram 1> messages.out 2> message.err or $ myprogram > messages.out 2> message.err

• Redirect standard error messages to the same place as standrd output

$ both >& outfile or $ both &> outfile or slightly more verbose $ both > outfile 2>&1

• append the output rather than clobbering it

$ myprogram >> output.file

• skip the header of a file

tail +2 lines which prints from line 2 onwards

• Don't want to save the output into a file;don't want to see it at all

$ find / -name myfile -print 2> /dev/null or $ noisy >/dev/null 2>&1

• Command chaining

  > $ ls;pwd;bla;goat