command substitution: ^

rhxk · 04-05-2006, 01:45 PM

Take a look at the cmd:

[robert@hydor bin]$ echo hi
hi
[robert@hydor bin]$ ^hi^this is a test
echo this is a test
this is a test
[robert@hydor bin]$

now, my last cmd was "echo this is a test".

So i know how to replace a string in the previous command, what if i want to replace say all the "i"s with any other letter?
...or to replace all the "is" with "hello" or whatever..

..any suggestions?..

--Rob

Centinul · 04-06-2006, 09:41 AM

That would require the use of SED. A tutorial can be found here.

To replace i's with another letter try

Code:

 echo "This is a Test" | sed -e 's/i/x/g'

That will replace all the i's with x's.

To replace is with hello try the following:

Code:

 echo "This is a Test" | sed -e 's/is/hello/g'

I apologize for the crude explanation. I would give the actual output w/ examples but I'm not on a linux machine currently so I cannot do that. With the code samples and a tutorial you should be good to go. Hope this helps!

nx5000 · 04-06-2006, 09:51 AM

Here's an example of what I use often, its very powerfull.

Code:

debian:~/bin# ls *.sh
iozone_part.sh  makefullbackup.sh  makeincrementbackup.sh  mmem.sh
debian:~/bin# ls -al !*
ls -al *.sh
-rwxr-xr-x 1 root root 1043 2006-04-04 03:18 iozone_part.sh
-rwxr-xr-x 1 root root  344 2006-02-27 02:35 makefullbackup.sh
-rwxr-xr-x 1 root root  466 2006-02-27 02:38 makeincrementbackup.sh
-rwxr-xr-x 1 root root   53 2006-03-04 22:20 mmem.sh
debian:~/bin# !ls:gs/sh/ps/
ls -al *.ps
-rw-r--r-- 1 root root 39878 2006-03-31 10:59 out.ps

Other thing very usefull is Ctrl-R in bash
type something like
l<ctrl-R>
press space and you will get your old command, then ctrl R to choose something else

man bash , man!