Question

Here is what I am trying to do.

File1:

abc
bcd
cde
def
efg
fgh
ghi

File2:

ip:/vol0/scratch/&
ip:/vol0/sysbuild/
ip:/vol0/cde
ip:/vol0/mnt/cm/&
ip:/vol0/&
ip:/vol0/mnt/fgh
ip:/vol0/mnt/&

As you can see File2 has & at the end of some lines, I need to replace the & with corresponding line in File1 and ignore the lines without the & For example, if line 2 and line 3 doesn’t have & the script would skip line 2 and 3 in both files and go to line 4 to replace the &

How would I achieve this with shell script.

Answer 1

Using paste and awk:

$ paste file2 file1 | awk 'sub(/&\s+/,"")'
ip:/vol0/scratch/abc
ip:/vol0/mnt/cm/def
ip:/vol0/efg
ip:/vol0/mnt/ghi

---

Wasn’t 100% clear if you wanted the lines not ending in & in the output:

$ paste file2 file1 | awk '{sub(/&\s+/,"");print $1}'
ip:/vol0/scratch/abc
ip:/vol0/sysbuild/
ip:/vol0/cde
ip:/vol0/mnt/cm/def
ip:/vol0/efg
ip:/vol0/mnt/fgh
ip:/vol0/mnt/ghi

With sed:

$ paste file2 file1 | sed -rn '/&/s/&\s+//p'
ip:/vol0/scratch/abc
ip:/vol0/mnt/cm/def
ip:/vol0/efg
ip:/vol0/mnt/ghi