I need to use sed on AIX to find and replace exact match of a string.
as an example we have a like like below
LogicalVolume hdisk1 hdisk10
and I have 2 variables
old_disk=hdisk1
new_disk=hdisk50
Here is the sed command I would like to use
sed "s/"$old_disk"/"$new_disk"/" file1.txt \> file2.txt
The outcome that I get looks like below
LogicalVolume hdisk50 hdisk500
instead of
LogicalVolume hdisk50 hdisk10
Unfortunately < and > do not work on AIX and I don't know how to replace the exact match of variable old_disk. I also tried ' and " around the variable, but it doesn't work neither.
Given that perl is available by default on AIX, I'd recommend using it to avoid using disk-related commands with mistaken data!
old_disk=hdisk1
new_disk=hdisk50
export old_disk new_disk
perl -pe 's/\b$ENV{"old_disk"}\b/$ENV{"new_disk"}/g' < file1.txt > file2.txt
This sets the same two variables as your example, then exports them into the environment so that the upcoming perl command can access them. The perl command simply searches and replaces any of the "old_disk" values with "new_disk" values, but restricts the search text by requiring it to have a word boundary on both sides. A word boundary is a change from a word character (alphanumeric and _) to a non-word character (or vice versa).