Programming Forums > Script Programming > Sed and Awk

Thaidog · Aug 15th, 2007, 12:13 PM

Can somebody please give me an example of the sed code that could uncomment a drive mount line in fstab?

Infinite Recursion · Aug 15th, 2007, 1:29 PM

Is it a particular line you are interested in? Are there other commented mounts that you want to exclude? What does your fstab look like?

To remove all # in the file you could do this:

cat fileA | sed 's/#//g' > fileB; mv fileB fileA

If you want a more specific line uncommented, need more info.

Thaidog · Aug 15th, 2007, 5:05 PM

Quote:

Originally Posted by Infinite Recursion

Is it a particular line you are interested in? Are there other commented mounts that you want to exclude? What does your fstab look like?

To remove all # in the file you could do this:

cat fileA | sed 's/#//g' > fileB; mv fileB fileA

If you want a more specific line uncommented, need more info.

There are two lines that need to be uncommented and a few others that need to stay commented.

The two that need uncommenting look like this:

#/dev/sde1 /vmware/tol ext3 nosuid 0 0
#/dev/sdf1 /vmware/sas ext3 nosuid 0 0

Infinite Recursion · Aug 16th, 2007, 10:47 AM

check out regular expressions and/or http://www.student.northpark.edu/pem...d/sed1line.txt

peace_of_mind · Aug 16th, 2007, 11:05 AM

Nice link. Thanks, IR.

Thaidog · Aug 16th, 2007, 3:15 PM

OK. How does this look?

sed 's/\(#\)\(/dev/sde1.*\)/\2/' /etc/fstab

sed 's/\(#\)\(/dev/sdf1.*\)/\2/' /etc/fstab

Infinite Recursion · Aug 16th, 2007, 3:47 PM

My shell responds with:
sed: command garbled: s/\(#\)\(/dev/sde1.*\)/\2/

You need to escape the / character... like this:

sed 's/\(#\)\(\/dev\/sde1.*\)/\2/' /etc/fstab
sed 's/\(#\)\(\/dev\/sdf1.*\)/\2/' /etc/fstab

The only difference is the sde vs sdf... regular expressions would allow you to process them with just one line. But if its a one time execution, save yourself the trouble.

You're welcome PoM...

There is another one for Awk floating around somewhere.

Thaidog · Aug 16th, 2007, 4:15 PM

Quote:

Originally Posted by Infinite Recursion

My shell responds with:
sed: command garbled: s/\(#\)\(/dev/sde1.*\)/\2/

You need to escape the / character... like this:

sed 's/\(#\)\(\/dev\/sde1.*\)/\2/' /etc/fstab
sed 's/\(#\)\(\/dev\/sdf1.*\)/\2/' /etc/fstab

The only difference is the sde vs sdf... regular expressions would allow you to process them with just one line. But if its a one time execution, save yourself the trouble.

You're welcome PoM...

There is another one for Awk floating around somewhere.

It's really just a one time execution. Thanks for the help! One last thing.... would the -i switch be a good idea here? For instance:

sed -i 's/\(#\)\(\/dev\/sde1.*\)/\2/' /etc/fstab

Infinite Recursion · Aug 17th, 2007, 3:16 PM

It works without the -i. I would leave it as is.

Aug 15th, 2007, 12:13 PM	#1
Thaidog Newbie Join Date: Sep 2004 Posts: 8 Rep Power: 0	Need sed to uncomment fstab file lines. Can somebody please give me an example of the sed code that could uncomment a drive mount line in fstab?

Aug 15th, 2007, 1:29 PM	#2
Infinite Recursion Programming Guru Join Date: Jul 2004 Location: United States Posts: 3,464 Rep Power: 8	Is it a particular line you are interested in? Are there other commented mounts that you want to exclude? What does your fstab look like? To remove all # in the file you could do this: cat fileA \| sed 's/#//g' > fileB; mv fileB fileA If you want a more specific line uncommented, need more info. __________________ http://jasonpowers.net "There are a thousand hacking at the branches of evil to one who is striking at the root."

Aug 16th, 2007, 10:47 AM	#4
Infinite Recursion Programming Guru Join Date: Jul 2004 Location: United States Posts: 3,464 Rep Power: 8	check out regular expressions and/or http://www.student.northpark.edu/pem...d/sed1line.txt __________________ http://jasonpowers.net "There are a thousand hacking at the branches of evil to one who is striking at the root."

Aug 16th, 2007, 11:05 AM	#5
peace_of_mind Professional Programmer Join Date: Sep 2004 Location: Hell if I know most of the time Posts: 435 Rep Power: 4	Nice link. Thanks, IR. __________________ Amateurs built the ark Professionals built the Titanic

Aug 16th, 2007, 3:47 PM	#7
Infinite Recursion Programming Guru Join Date: Jul 2004 Location: United States Posts: 3,464 Rep Power: 8	My shell responds with: sed: command garbled: s/\(#\)\(/dev/sde1.\)/\2/ You need to escape the / character... like this: sed 's/\(#\)\(\/dev\/sde1.\)/\2/' /etc/fstab sed 's/\(#\)\(\/dev\/sdf1.*\)/\2/' /etc/fstab The only difference is the sde vs sdf... regular expressions would allow you to process them with just one line. But if its a one time execution, save yourself the trouble. You're welcome PoM... There is another one for Awk floating around somewhere. __________________ http://jasonpowers.net "There are a thousand hacking at the branches of evil to one who is striking at the root."

Aug 16th, 2007, 3:15 PM	#6
Thaidog Newbie Join Date: Sep 2004 Posts: 8 Rep Power: 0	OK. How does this look? sed 's/\(#\)\(/dev/sde1.\)/\2/' /etc/fstab sed 's/\(#\)\(/dev/sdf1.\)/\2/' /etc/fstab

Aug 17th, 2007, 3:16 PM	#9
Infinite Recursion Programming Guru Join Date: Jul 2004 Location: United States Posts: 3,464 Rep Power: 8	It works without the -i. I would leave it as is. __________________ http://jasonpowers.net "There are a thousand hacking at the branches of evil to one who is striking at the root."

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
problem processing file into a char array	csrocker101	C++	1	May 8th, 2007 11:50 PM
converting string to float	beginnerCCC	C	22	Oct 2nd, 2006 11:59 PM
OnlineTextEditor.Com!	Sane	Show Off Your Open Source Projects	43	Jun 16th, 2006 8:55 AM
After execution - Error cannot locate /Skin File?	wchar	Visual Basic	1	Mar 5th, 2005 9:04 PM
airport Log program using 3D linked List : problem reading from file	gemini_shooter	C++	0	Mar 2nd, 2005 4:12 PM

Programming Forums > Script Programming > Sed and Awk

Need sed to uncomment fstab file lines.