Shell Programming and Scripting

Can you please help me to edit parts of a file and write into a new file.
=====================================
Suppose I have a huge data dump in a file I need to search for a tag in that and cut few lines around that tag in the file. Is there a way to keep track of line numbers and operate on the file.

I can explain with example.
I have this file AAA
-----AAA------
Start:
name:1111
date:222
id:3333
address:12444
end
Start:
name:5555
date:3312
id:6666
address:qwds
end
Start:
name:7777
date:9090
id:4571
address:abc444
end
----------------
ID is unique for each start-end block in above file.
In above file, I need to search for a ID, say 4571 and just extract the block Start-End having details about id:4571
expected output is:
name:7777
date:9090
id:4571
address:abc444

can you please suggest how I can go about getting the necessary data from AAA given a ID as input?

Code:

$ cat AAA
Start:
name:1111
date:222
id:3333
address:12444
end
Start:
name:5555
date:3312
id:6666
address:qwds
end
Start:
name:7777
date:9090
id:4571
address:abc444
end
$
$
$
$ cat srch.sh
#!/usr/bin/ksh

idval=$1
fn=$2
[ -z "${idval}" ] && exit 1
[ ! -s "${fn}" ] && exit 2
ln=`grep -n "^id:${idval}$" $fn |cut -d":" -f1`
st=$(( ln - 2))
to=$(( ln + 1))
sed -ne "${st},${to}p" AAA
$
$
$ ./srch.sh 4571 AAA
name:7777
date:9090
id:4571
address:abc444

HTH

Code:

grep -A 1 -B 2 'id:4571' file.txt

Context options in grep are not universal. e.g. the -A / -B options won't work on solaris grep.

There is no comment regarding the OS.

Well, doesn't hurt to have a "more-compatible" solution!

Краткость сестра таланта.