Yes, you are confusing yourself and us.

In sed you do not append text to the end of a line. The sed a command appends lines of text following the current line. And, the sed i command inserts lines of text before the current line.

You use the sed s command to replace or substitute specified text on a line with replacement text that you specify. If you want to replace the text OK at the end of a line with the string _DLY-OK, you use:

Code:

sed 's/OK$/_DLY-&/' input_file > output_file

where the $ in OK$ anchors the matched text to the end of the line. OK found anywhere but at the end of the line will not be affected by this substitute command.

If you want to do that AND change every occurrence of the string daisy to the string tulip no matter where it appears on an input line, you use:

Code:

sed -e 's/OK$/_DLY-&/' -e 's/daisy/tulip/g' input_file > output_file

The -e was optional in the sed command above, but both -e options are required in this command. The sed command always takes at least one command argument. If there is more than one sed command argument, you need -e options in front of them so sed can determine which arguments are sed commands and which arguments are the names of files to be processed.

The g flag at the end of the substitute command s/daisy/tulip/g tells sed to make that substitution globally on each addressed line. Without the g flag (i.e., s/daisy/tulip/), only the first occurrence of daisy on each addressed line would be changed to tulip.