Shell Programming and Scripting

Originally Posted by Don Cragun

Yes. I would have stated how it behaves as: If a line contains the string "123:abc:" change the 2nd occurrence of ":" on that line to ":$" and then print the modified line.


The standards don't have an I flag for the sed s command. The Mac OS X system I use when testing stuff I post on this forum doesn't have an I flag for th sed s command. The Linux man sed man page in this forum doesn't mention any flags but says to look for another document that I don't have to determine how sed works on Linux.

If you can tell me what the I flag is supposed to do, I may be able to help, but I have no idea what it does nor why you would want to use it.

I missed the part about changing colons to commas. I still don't have a clear statement of what you're really trying to do. So, back to my original posting:

If you just want to add a $ after the 2nd colon and change colons to commas in each line, try:

Code:

sed 's/:/,/;s/:/,$/' input_file

If you just want to do that on a line that starts with 123:abc: and only print lines that sed modifies, try:

Code:

sed -n 's/:/,/;/123,abc:/s/:/,$/p' input_file