Break one liner command line script after first match

saumitra121 has asked for the wisdom of the Perl Monks concerning the following question:

I have a file which have data like

this is some data
this is other data
this is new data
[download]

Now I want to check(using a regex) whether a pattern exist in file or not. If yes then print the matched text and exit. In case the pattern occurs more than once, then the one liner should break after first match.

Lets for example say that I want to check for pattern "data" in my file. I am using following one liner.

 perl -ne'/(data)/ && print $1' file.txt
[download]

The problem with this is that it is NOT exiting after first match and prints matched content thrice.

How can I modify this so that execution will stop after first match?

Please note that instead of "data" i can provide any regex. Also I can't use a script. This has to be a command line one liner in perl(no awk or grep). File size can be as big as 2 GB.

Comment on Break one liner command line script after first match Select or Download Code

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Re: Break one liner command line script after first match by McA (Priest) on Oct 30, 2013 at 12:03 UTC
Hi why not just exiting after printing the matched line? UPDATE: `perl -ne'/(data)/ && print($1) && exit' file.txt` McA	[reply] [d/l]
Re^2: Break one liner command line script after first match by hdb (Monsignor) on Oct 30, 2013 at 12:33 UTC
Or die! `perl -ne'/(data)/ && die $1' file.txt` [download]	[reply] [d/l]
Re: Break one liner command line script after first match by 2teez (Vicar) on Oct 30, 2013 at 12:51 UTC
How can I modify this so that execution will stop after first match You can do: `perl -ne'/(data)/ && print $1 and last' file.txt` If you tell me, I'll forget. If you show me, I'll remember. if you involve me, I'll understand. --- Author unknown to me	[reply] [d/l]
Re^2: Break one liner command line script after first match by McA (Priest) on Oct 30, 2013 at 13:01 UTC
Hi, as you showed it with your solution: Be aware of the subtle difference between: `perl -ne'/(data)/ && print $1 and last' file.txt perl -ne'/(data)/ && print $1 && last' file.txt` [download] That may bite someone (by the way: I was bitten ;-) ) McA	[reply] [d/l]
Re^3: Break one liner command line script after first match by 2teez (Vicar) on Oct 30, 2013 at 13:24 UTC
Hi, Be aware of the subtle difference between: `perl -ne'/(data)/ && print $1 and last' file.txt perl -ne'/(data)/ && print $1 && last' file.txt` [download] Of course, I saw the subtle difference, and how you used `.. print ($1) ...` [download] the parentheses which is effectively the same thing if "and" is used instead of "&&" check this: Using `perl -MO=Deparse -ne'/(data)/ && print $1 && last' file.txt` [download] you gets: `LINE: while (defined($_ = <ARGV>)) { print $1 && last if /(data)/; }` [download] but using `perl -MO=Deparse -ne'/(data)/ && print ($1) && last' file.txt` [download] gives: `LINE: while (defined($_ = <ARGV>)) { last if /(data)/ and print $1; }` [download] Which is same as this: `perl -MO=Deparse -ne'/(data)/ && print $1 and last' file.txt` [download] `LINE: while (defined($_ = <ARGV>)) { last if /(data)/ and print $1; }` [download] If you tell me, I'll forget. If you show me, I'll remember. if you involve me, I'll understand. --- Author unknown to me	[reply] [d/l] [select]
Re^4: Break one liner command line script after first match by McA (Priest) on Oct 30, 2013 at 13:32 UTC