How to fix "Software selection (Source changed - please verify)"
This is one of the most common error you will face if you are working on unattended Red Hat Linux installation where you have a customised list of Packages. **Error:**
Linux
sed: remove all leading and ending blank whitespace from a file
Here our requirement is to remove all the whitespace from the leading and ending space per line of a file. Our sample file /tmp/file This is line one This is
sed: Insert multiple lines before or after pattern match
In my last articles I had shown you the arguments to be used with sed to add or append any character in the beginning or end of the line and
sed: Replace string based on line number (certain line)
Here our requirement is that we have a file where we have to perform a string replacement **but based on line number.** Below is our sample data /tmp/file 1 This
sed :Replace whole line when match found
Here our requirement is to replace a line with our content when a match is found with in the file Our sample file /tmp/file This is line one This is
sed: match string and append new line (before or after)
Before is the requirement for this example. I have a sample file with below content at /tmp/file This is line one This is line two This is line three This
How to add line number at the beginning of each line
There are many ways to do this, I will try to show some Sample file '/tmp/file' Apple Apricot Avocado Banana Bilberry Blackberry Blackcurrant **Method 1** Using 'nl' # nl /tmp/file
sed: Insert character in the beginning or end of line with matched pattern
In my last articles I had shared the arguments with sed which can be used to [perform case insensitive actions (search, replace..) in a file]({{< relref "sed-case-insensitive-actions-search/index.md" >}}) and to [delete all blank
sed: insert word or text after match in middle of the line (search and append a string before or after match)
#### How to append a string after a match? For eg I have a text line "**This is not test**" where I would like to insert "**really**" after matching "**is**"
Verification Failed - Error connecting to the Apple ID Server
#### Unable to connect to iCloud Server or iTunes from your laptop? I recently did an update of iTunes on my laptop after which I was unable to re-login to