Cocoa, Objective-C, and Perl

All computer languages have their advantages and disadvantages. Perl is a great language for parsing and massaging text. If you are writing a Cocoa, Objective-C program, and you need to parse and massage text, you may want to hand that task off to some Perl code. This can be easily done. OS X comes with Perl installed, and you can have a Perl program as one of the resources in your Cocoa application. Following is some sample Objective-C code and Perl code that illustrates how to launch a Perl program that will write a temporary file that can then be read by your Objective-C code:

Here is the Objective-C code to set up and launch the perl program:

// define your temp file
FILE *fp;
NSMutableString *tmpPath = [[NSMutableString alloc] initWithString:@”"];
[tmpPath setString:@"tempfilepath/tempfilename"];

// this is the path to your perl program
plPath = [thisBundle pathForResource:@"perlpgm" ofType:@"pl"];

// array to pass arguments to your perl program
NSMutableArray *argArray = [[NSMutableArray alloc] initWithObjects:plPath,tmpPath,nil];
// launch the perl program & wait for it to finish
[[NSTask launchedTaskWithLaunchPath:[NSString stringWithFormat:@"/usr/bin/nice"] arguments:argArray] waitUntilExit];

// open the temp file that has been written by the perl program
fp = fopen([tmpPath UTF8String], “r”);

// process the contents of the temp file here

fclose(fp);

// remove the temp file when you’re done
NSFileManager *manager = [NSFileManager defaultManager]
[manager removeFileAtPath:tmpPath handler:nil];

And here is what the code in your perl program will look like:

$tempFile = shift;
open ( TMPFILE, “$tempFile” ) || print STDERR “problem opening $tempFile\\n”;

# do your text massaging here and write the temp file.

close TMPFILE;

Of course you can also use STDIN and STDOUT if you don’t want to write a temporary file.

2 Responses to “Cocoa, Objective-C, and Perl”

  1. Feseha Says:

    Thank you for an excellent and very useful post. This post was like finding a PERL in a pile of worthless pebbles!
    Thanks

  2. Brittany Monohan Says:

    tarnówI truly appreciate this post. I?¦ve been looking all over for this! Thank goodness I found it on Bing. You’ve made my day! Thank you again

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