How to write bash script or automate the open vi and edit document?

Question

I'd like to write a bash script that essentially automates this process:

vi filename.sh

(open "filename.sh" using vi)

add the following 2 lines:

export GRADLE_HOME=/opt/gradle/gradle-5.2.1
export PATH=${GRADLE_HOME}/bin:${PATH}

and save those changes

:wq!

Basically I want to add these in jenkins file for automation

Answer 1

vi is by definition a visual editor.

In this case it's probably better to use some other means.

If you only want to append those lines, do something like:

cat >> filename.sh <<'EOF'
export GRADLE_HOME=/opt/gradle/gradle-5.2.1
export PATH=${GRADLE_HOME}/bin:${PATH}
EOF

This will also work if the file doesn't exist yet.

If you want those lines added at the beginning, you can use ed which is a line-oriented editor:

ed filename.sh <<'EOF'
1i
export GRADLE_HOME=/opt/gradle/gradle-5.2.1
export PATH=${GRADLE_HOME}/bin:${PATH}
.
w
q
EOF

This instructs ed to insert lines at line 1; the solitary dot . on the line indicates the end of input, so insertion stops there. Finally the file is written (w) and the edit session quitted (q).

If you insist on using ed even if the file doesn't exist yet (in which case I would use the cat example above), you can use this:

ed filename.sh <<'EOF'
i
export GRADLE_HOME=/opt/gradle/gradle-5.2.1
export PATH=${GRADLE_HOME}/bin:${PATH}
.
w filename.sh
q
EOF

The main difference is that you don't pass a line number with the i insert command, as there are no lines yet; and you pass a filename to the w write command which is the new file.

sed can also be used, but for such tasks I find ed easier to use (and to read what's happening).

Answer 2

Automated scripting can be done using ed

like ed < edit.sed filename.pdf

For more, you can visit this tutorial.

Answer 3

I would also do it the way @wurtel is suggesting, but if for some reason you really want to do it with vi, add the following to your $HOME/.vimrc file:

function AddVars()
    let line1 = "export GRADLE_HOME=/opt/gradle/gradle-5.2.1"
    let line2 = "export PATH=${GRADLE_HOME}/bin:${PATH}"
    call append(line('$'), line1)
    call append(line('$'), line2)
    write
    exit
endf

And then call vi with using the -c option like this: vi filename.sh -c "call AddVars()"