CODEWITHSUNDEEP
java
user1522820
user1522820

Reputation: 1604

OS Utilities vs Java API's for text search in a file

Suppose i want to search some text in a file. I want to know when we should use system utilities/programs like grep and when we should use Java API's like reading a line, and then search the text in that line or use java Scanner class.

I want to understand the trade-offs between the two approaches. I mean, suppose if we use grep, then will there be communication overhead between JVM and the grep process? Is creation of a new OS process for grep an overhead?

Does grep performs better than normal java file search?

Please help...

Upvotes: 1

Views: 190

Answers (2)

MadProgrammer
MadProgrammer

Reputation: 347214

You're basically trading off system independence for the perceived gain of the tool, in some cases this can't be avoid.

Not every system will have the tools you want installed, in the locations you think they should be or the version you need.

Even if you can deploy the tools with your application, you will need to provide an implementation for each of your targeted platforms.

Sure, it's easy to say "it will never be run on X", but can never come around real quick ;)

There is also the added over head of executing and managing the IO of the external applications, while not difficult, it's much more complex that a well written Java API.

As I said, sometimes, you simply don't have a choice (I have some media inspection tools that I use on Windows and Mac that I'm not about to try and implement in Java, not because it can't be, but because it's complex and time consuming and somebody has already done it (with a native program)).

You need to balance the choice over what the benefits are of the external command weight against the issues of using it. You should also investigate if a API has already begin developed that might solve the problem at hand.

IMHO

Upvotes: 0

JB Nizet
JB Nizet

Reputation: 691765

Yes, there will be an overhead. Starting an external process and communicating with it is costly. And moreover, many systems don't have a grep command. If you want to make your Java code portable, don't rely on OS-specific commands.

Another problem is that OS commands will be able to search (for example) in files, but not in your in-memory data structures.

Upvotes: 2

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