topic Re: change a line in a file in Operating System - Linux

change a line in a file

Anand_30 — Wed, 11 Jan 2006 14:19:09 GMT

Hi,

I have migrated some web application from one server to a new server.

Now I have around 150 html files in which I have to change the server names.

I know that I can use 'sed' to do it without opening the file but I will have to create a new file everytime I make change to an existing file.

Can anyone please tell me a more suitable way to perform the changes in the file.

Thanks,
Anand

Re: change a line in a file

James R. Ferguson — Wed, 11 Jan 2006 14:26:55 GMT

Hi Anand:

Use perl and do in-place modification:

# perl -i.old -pe 's/oldname/newname/g' file1 file2 ...

If you don't want to preseve a pre-modified copy, do:

# perl -i -pe 's/oldname/newname/g' file1 file2 ...

That is, simply drop the argument (for example ".old") following the '-i' option.

Multiple files can be specified at once as noted.

Regards!

...JRF...

Re: change a line in a file

Jeff_Traigle — Wed, 11 Jan 2006 14:31:48 GMT

You can use ex to edit them in place.

for FILE in list_of_files
do
ex ${FILE} <1,$s/oldhostname/newhostname/g
wq!
EOD
done

(I think I remember the syntax of the substitution, but you might want to test it to be sure.)

Re: change a line in a file

Peter Nikitka — Wed, 11 Jan 2006 14:33:59 GMT

Hi,

in this cases I generate ed-commands to do this.
Note1: Backup the files before you try!
Note2: use your appropriate method of getting the filenames
Note3: better tighten the pattern used for the global match (2nd print statement)

oldserver=XXX
newseerver=YYY
for f in $(fgrep -l $oldserver *.html)
do
print f $f
print g/$oldserver/s/$oldserver/$newserver/g
print w
done | ed

to review the ed-commands use this last line:
...
done >/tmp/ed.cmd

and then execute them via

ed
Use 'ed -s' istead of 'ed' to suppress ed-output.

mfG Peter

Re: change a line in a file

Peter Nikitka — Wed, 11 Jan 2006 14:36:22 GMT

Hi,

typo - change
for f in $(fgrep -l $oldserver *.html)
do
print f $f

to

print e $f

mfG Peter

Re: change a line in a file

Arturo Galbiati — Thu, 12 Jan 2006 04:12:12 GMT

Hi,
I use the ChanheSTring.ksh attched to perofrm this. It makes a backup copy of teh files changed and show you the line changed.
I love it.
HTH,
Art