shell script: insert line in a file
 

I want to append to line number 45 of a file. Currently I am doing echo "something" >> file which puts "something" at the end of the file. But I would like to echo to, say, line number 33.

Thanks for any help.

sounds like homework, soooo....

what you need to do is separate the file into parts, output part 1 to a file, then the line to insert, then part 2 to the file.

head and tail can help, i.e. "head -n 10 myfile" will print out the first 10 lines of "myfile". "tail -n 10 myfile" will print out the last 10 lines of "myfile". "wc -l myfile" will count the number of lines in "myfile".

Hopefully that's enough to get you going. ;)

You could use awk - something like:

awk '{if(NR == 45) {print "new line" >>"myfile"}}'

(Not tested)

Sorry if you misunderstood but this is not homework - I needed to add some lines through a shell script to my squid config file.

Thanks!This helps. Good ol' awk.

another way

sed way:
use -i to edit in place redirect using '> outfile' to copy it to another file.
Also the backslash isn't necessary, I just put it there for clarity.
is the same thing.