replace first instance(not first instance in line)

IronHorse7 · #1 (**permalink**) 02-07-2008

Alright, I think I know what I am doing with sed(which probably means I don't). But I cant figure out how to replace just the first occurance of a string. I have tried sed, ed, and grep but can't seem to figure it out. If you have any suggestions I am open to anything!

fpmurphy · #2 (**permalink**) 02-07-2008

By "first occurance" do you mean first occurance in a line or first occurance in a file?

fpmurphy · #3 (**permalink**) 02-07-2008

Assuming it is the first occurance in a file, the following example should show you how to
do what you want to do using awk.

Code:

$ cat file
true line1
true line2
$ awk '/true/ && n == 0 { sub(/true/,"false"); ++n } { print }' file
false line1
true line2
$

IronHorse7 · #4 (**permalink**) 02-07-2008

You are awsome, THANKS!

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