How to include variables in the sed command?

Question

grep -F "$name" -A1000 filename | sed -n '1p;19p;24p'

Assume let a=10,b=20,c=30.In the above grep command can I use '$ap;$bp;$cp' instead of '1p;19p;24p'?

Another thing, I've given as -A1000. Which implies that starting from 1p it considers till 1000 line , right? I need to search throughout file without giving the number.

@ evil otto : I tried in double quotes too. But getting error as invalid path context. — Jackie James, Jun 05 '12 at 16:59
Jackie, the question would be improved by naming the shell that you are using. — Rob Kielty, Jun 05 '12 at 16:59

score 6 · Accepted Answer · edited Jun 05 '12 at 17:04

6

If you want to include variables inside quotes, you need to use " instead of '.

If you want to add alphanumeric suffix to a variable you need to indicate that it's not part of it's name.

sed -n "${a}p;${b}p;${c}p"

Or:

sed -n "$a"'p;'"$b"'p;'"$c"'p'

edited Jun 05 '12 at 17:04

Paul

139,544
27
275
264

answered Jun 05 '12 at 17:00

Piotr Praszmo

17,928
1
57
65

@ PsulP.R.O. & Banthar : How about -A1000 ? Is it necessary to mention that respective number of lines (1000) ? or is it ok, if i just mention as -A ? – Jackie James Jun 05 '12 at 17:13
@JackieJames I'm not sure what you are trying to achieve. Do you want [all lines after match](http://stackoverflow.com/questions/5968107/get-everything-in-a-file-after-a-grepd-string)? – Piotr Praszmo Jun 05 '12 at 17:21
@ Banthar : I just want to print the lines in the sed command . How can i make it ? – Jackie James Jun 05 '12 at 17:26
@JackieJames If you don't need grep just do: `sed -n '1p;19p;24p' "$name"` – Piotr Praszmo Jun 05 '12 at 17:30
@ Banthar : Plzz go through thr link 'How to retrieve the specified parameters in a file (Shell Scripting )?' & let me knw which command to use. – Jackie James Jun 05 '12 at 17:47
@JackieJames I still don't understand. What are you trying to achieve with `grep -A1000` and why isn't it good? – Piotr Praszmo Jun 05 '12 at 18:00
@ Banthar : Tell me, wat does this command perform sed -n '1p;19p;24p' "$name" ? – Jackie James Jun 05 '12 at 18:03
@ Banthar : does this command sed -n '1p;19p;24p' "$name" require file name in it ? – Jackie James Jun 05 '12 at 18:12

How to include variables in the sed command?

1 Answers1