Shell Programming and Scripting

sorry mybad.. :-) i had made a silly mistake in the code.. :-)

---------- Post updated at 11:43 AM ---------- Previous update was at 11:42 AM ----------

but still i need help with my second doubt.. that is how to make sed not display all the contents of the file when its run...?

I think this option might help u...

-n, --quiet, --silent
suppress automatic printing of pattern space

Sed will by default print all the lines in pattern space. If you want it to change this, use the -n switch. Try this:

Code:

startpoint='`HOOOP`' 
sed -n '/CREATE TABLE '$startpoint'/,${p; /^) ENGINE/q}' mysql.big

This will start printing every lines after "CREATE TABLE $startpoint", including, and will quit (q) when the line begins with ') ENGINE'.

thanks siva shankar.. it worked :-)

---------- Post updated at 12:10 PM ---------- Previous update was at 12:09 PM ----------

oh this idea is good, i will try it out now mirni.. :-) thanks

---------- Post updated at 12:35 PM ---------- Previous update was at 12:10 PM ----------

@mirni.. i tried the below thing

Code:

echo "`sed -n '/CREATE TABLE \`$table_name1\`/,${p; /^) ENGINE/q}' testdump2.sql > tablextract2.sql`"

but the file is empty... and also after changing most of the while loops the code is reduced from 14 secs to 13.5 secs execution time for a file with 4 tables... i think its consuming time while comparing two tables extracted into a file.. the comparion algorithm which i am using is bubblesort.. that is first line is compared with all the lines in other file.. etc etc.. i think i have to try `diff `command and put the differences to a new file and try out to extract line from this.. will try this method today.. hope it works out :-\

Try this snippet...

sed -n '/CREATE TABLE \`$table_name1\`/,/^ENGINE/w tablextract2.sql}' testdump2.sql

As mentioned before, sed's pattern matching is greedy. It will write all lines between the first 'CREATE TABLE' and last '^ENGINE'. That's why this will not work the way OP wants.

consider the contents of the file is

Code:

cat tablextract.sql
CREATE TABLE `Table33` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`allianceId` int(11) NOT NULL,
`migratedAt` datetime DEFAULT NULL,
`migrationDetail` text COLLATE utf8_unicode_ci,
`unigyId` int(11) DEFAULT NULL,
PRIMARY KEY (`id`)
)

and

Code:

col="id"

so if i perform

Code:

 cat tablextract2.sql | grep $col

or

Code:

 line=`cat tablextract2.sql | grep $col`

it displays two line since id is present in two lines.... so my question is how to make it display one line after another say in "for" loop or something like that.. i want to work on them individually so...