Quickest Way to Shell

Cocoa provides NSTask to run subprocesses. It can be used to run shell scripts, but all this manual pipe and file handling is a bit cumbersome. Fortunately, for a simple script, we can use the trusty old system and redirect its result to a file.

Here's a quick way to get the path to the last crash report of your app :

// We'll save the result in a temp file
NSString* tempFilePath = [NSString stringWithFormat:@"%@/MyApplicationLastCrash.txt", NSTemporaryDirectory()];

// Run the shell script
NSString* script = [NSString stringWithFormat:
  @"ls -1t /Users/mini/Library/Logs/CrashReporter/* | grep /MyApplication | head -1 | tr -d '\n' >%@", tempFilePath];
system([script UTF8String]);

// Returns path to last crash report or empty string ( [lastCrash length == 0] )
NSString* lastCrash = [NSString stringWithContentsOfFile:tempFilePath encoding:NSUTF8StringEncoding error:nil];
In this case, ls lists all crash reports from new to old, grep keeps only yours, head and tr extract the result by keeping the first line and removing the trailing newline. Getting the path is now only a matter of reading the temp file.

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