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.

This entry was posted on Monday, February 28th, 2005 at 2:10 pm and is filed under General. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.