Wsrtjtyk

From this I found the command and it works without any command substitution. But if I try to substitute a variable in the command, I get the following problems.

Note: I am using sed command(BSD OSX) / MacOS

To reproduce just create a file.txt with this:

SOME_TEXT

CHANGE_THIS

CHANGE_THIS

CHANGE_THIS

Add TMP variable in you terminal:

TMP=export PATH=/Users/Name/with pace/and_variables:$PATH

Now with this command:

sed -i '' "1h; 1 $ { x; s/CHANGE_THIS/$TMP/; p; }" file.txt

I get this error:

sed: 1: "1h; 1 $ { x; s/CHANGE_T ...": invalid command code $

In a privious answer I got this("," added to "1,$":

sed -i '' "1h; 1,$ { x; s/CHANGE_THIS/$TMP/; p; }" file.txt   

expected output file.txt

SOME_TEXT

export PATH=/Users/Name/with pace/and_variables:$PATH

CHANGE_THIS

CHANGE_THIS

I get this:

SOME_TEXT

SOME_TEXT

SOME_TEXT

SOME_TEXT

Could you please try following if you are ok with awk.

##Creating shell variable named TM here.

TMP="export PATH=/Users/Name/with pace/and_variables:$PATH"

awk -v tmp="$TMP" '/CHANGE_THIS/ && ++flag==1{$0=tmp} 1' Input_file

In case you want to save output into Input_file itself then append > temp_file && mv temp_file Input_file in above code too.

Adding explanation for above code too here.

awk -v tmp="$TMP" '              ##Creating an awk variable named tmp whose value is bash variable TMP value.

/CHANGE_THIS/ && ++flag==1{      ##Checking condition if a line is having string CHANGE_THIS and variable flag value is 1 then do following.

  $0=tmp                         ##Setting current line value to value of tmp awk variable here.

}                                ##Closing the block for condition here.

1                                ##By mentioning 1 printing edited/non-edited line here.

' Input_file                     ##Mentioning Input_file name here.

Use:

sed -i '0,/.*CHANGE_THIS.*/s//my changed line/' file