SED read text from a file and replace at line 79?

gdizzle · 07-28-2015, 02:31 AM

Hi there I have text in a file:

Code:

cat  /etc/openldap/passwd
password

I want to read the string from the file
/etc/openldap/passwd and paste the string in this file /etc/openldap/changes.ldif on line 79 in this format.

Code:

olcRootPW: password

Any ideas?

Thanks

syg00 · 07-28-2015, 03:06 AM

Several.

Since you mention sed in the subject, it will handle it nicely - it accepts addresses, which can be a line number, and bash variables.
You can probably find most of what you need in the sed one-liners .
You make an effort, we'll help with any problems you find insurmountable.

rhubarbdog · 07-28-2015, 05:14 AM

how often do you need to do this. if less than monthly just use a text editor which can copy and paste between files. any automation is probably fool hardy can you guarentee that line 79 *always* needs pasting into the other file at the *same* guarenteed point

HMW · 07-28-2015, 05:53 AM

Ok, I'll bite.

Given that you have a file with this content:

Code:

cat aline.txt 
line_to_copy

You can get that into a variable like this:

Code:

aline=$(cat aline.txt)
echo $aline 
line_to_copy

Now, say that you want to insert at line 3 in this file (to_insert.txt):

Code:

Line 1
Line 2
Line 3
Line 4
Line 5

You can use this sed:

Code:

sed -i.bak "3c $aline" to_insert.txt

Which gets you the following result:

Code:

Line 1
Line 2
line_to_copy
Line 4
Line 5

You will have to implement that in your own script of course.

Best regards,
HMW

gdizzle · 07-28-2015, 08:30 PM

Thanks I was overthinking this:

password="$(cat /etc/openldap/passwd)"
olcRootPW: "$password"