How to replace, from command-line, the content between <!-- Analytics code start --> and <!-- Analytics code end --> of index.html:
<html> ... <!-- Analytics code start --> ... <!-- Analytics code end --> </body> </html> by the content of a file, say myanalytics.txt ?
Note: I want to do it by command-line because I need to do it for many files.
A solution with awk could be:
awk '/Analytics code start/ { t=1; print; system("cat myanalytics.txt") } /Analytics code end/ { t=0 } t==0 { print } ' index.html (I indented the code to increase readability, but it can easily be a oneline)
Briefly explanation:
t==0 always print the current line "Analytics code start" set t==1 and then print the current line and the desired file with system("cat myanalytics.txt")t is equal to 1 so the current line is never printed, but when the current line matches "Analytics code end", t is set to 0 again, so print the current line from now on.Note:
This will not edit your file index.html. To modify index.html you can:
redirect the output from awk to a temporary file, and then use a command likemv or cp
use sponge from moreutils package, as follow:
awk '[.. commands like above ..]' index.html | sponge index.html Given your situation, here's how you could do this:
#!/bin/sh SOURCE=index.html if ! test -f "$SOURCE"; then echo source is missing >&2 exit 1 fi headLimit=`grep -n '<!-- Analytics code start -->' "$SOURCE" | cut -d: -f1` tailLimit=`grep -n '<!-- Analytics code end -->' "$SOURCE" | cut -d: -f1` linennr=`awk '{}END{print NR + 1}' $SOURCE` if ! test "$headLimit" -gt 0 -a "$tailLimit" -gt 0 >/dev/null; then echo something is wrong >&2 exit 2 fi ( head -n$headLimit "$SOURCE" echo "the stuff I want to inject in place of my analytics code" tail -n`expr $linennr - $tailLimit` "$SOURCE" ) >"$SOURCE.new" if test -s "$SOURCE.new"; then mv "$SOURCE" "$SOURCE.old" mv "$SOURCE.new" "$SOURCE" fi exit 0 Note that any ed based solution would allow to actually replace in-file, instead of generate a replacement one, ... Which would arguably be cleaner.
i think this maybe work
sed -rn '/<!-- Analytics code start -->/{ p; :X n; /<!-- Analytics code end -->/{p;b}; bX }; p' 
<!-- Analytics code start -->is at the line 4, and<!-- Analytics code end -->is the line 10. Do you wanna change the lines 4 and 10, or the lines between 4 and 10 ??