Overview

FindExecutableInPath allows you to search directories in $PATH for a specific executable name.

$PATH Notes

The default $PATH returned by NSProcessInfo only includes /usr/bin, /bin, /usr/sbin and the user’s home directory.

In the code below, I’ve also added /sw/bin (Fink), and /usr/local/bin, which are common locations for third-party command-line applications.

Credits

This is based on the example provided on the AllApplications page.

Code

• (void)applicationsInDirectory:(NSString)searchPath searchResults:(NSMutableArray)resultPaths file:(NSString*)filename { NSFileManager *manager = [NSFileManager defaultManager]; NSArray *files = [manager directoryContentsAtPath:searchPath]; NSEnumerator *fileEnum = [files objectEnumerator]; NSString *file;

  while (file = [fileEnum nextObject]) { [manager changeCurrentDirectoryPath:searchPath]; if ([manager isExecutableFileAtPath:file]) { NSString *fullpath = [searchPath stringByAppendingPathComponent:file]; if ([file isEqualToString:filename]) { [resultPaths addObject:fullpath]; } } } }

• (NSArray)allApplications:(NSArray)searchPaths file:(NSString*)filename { NSMutableArray *resultPaths = [NSMutableArray array]; NSEnumerator *searchPathEnum = [searchPaths objectEnumerator]; NSString *path;

  while (path = [searchPathEnum nextObject]) { [self applicationsInDirectory:path searchResults:resultPaths file:filename]; }

  return ([resultPaths count]) ? resultPaths : nil; }

• (void)findExecutableInPath:(NSString *)filename { NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

  /* ======================================================================= / / 1. Setup Search Path array based on default $PATH environment variable. / / 2. Add path to fink bin directory and /usr/local/bin / / ======================================================================= */

  NSString *searchPath = [NSString stringWithUTF8String:getenv(“PATH”)]; searchPath = [searchPath stringByAppendingString:@”:/sw/bin:/usr/local/bin”]; NSArray *searchPaths = [searchPath componentsSeparatedByString:@”:”];

  //NSLog(@”%s: Searching Paths %@”, _cmd, searchPaths); NSArray *executablePaths = [self allApplications:searchPaths file:filename];

  if ([executablePaths count] > 0) { // Do something with the path here //NSLog(@”%s: executable Paths %@”, _cmd, executablePaths); }

  [pool release]; }

</code>

– ncb

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This code is ridiculously convoluted and won’t even work. It is good to test your examples before posting them. (The initializer for searchPath is totally broken, will produce a warning, and will crash when run. There may be other problems.)

I would suggest code like the following (uses a ForallMacro):

NSArray *ExecutablesInPath(NSString *name) { NSMutableArray *retVal = [NSMutableArray array]; NSString *pathEnv = [[[NSProcessInfo processInfo] environment] objectForKey:@”PATH”]; NSArray *paths = [pathEnv componentsSeparatedByString:@”:”]; forall(path, paths) { NSString *executablePath = [path stringByAppendingPathComponent:name]; if(IsExecutable(executablePath)) [retVal addObject:executablePath]; } return retVal; }

Note that this code is also not tested, as it is meant to illustrate the technique, handle with caution.

The implementation of IsExecutable is left as an exercise to the reader. Depending on what you want to do, you may want to check for +x, or for a .app wrapper, or something else.

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Woops.

I’ve fixed the code to to use getenv(“PATH”) for the searchPath initialisation.

– ncb

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I’ve fixed the code not to leak and to work properly with non-ASCII paths. (See StringWithCString for why this is.)