A redacted file from the Waldo machine on HTB.

logmonitor.c

/*******************************************
*
*This is an application to print out common log files
*
********************************************/

#include "logMonitor.h"

void printUsage() {
    printf("Usage: %s [-aAbdDfhklmsw] [--help]\n", PROGRAMNAME);
}

int main(int argc, char** argv){
	int opt = 0;
	char filename[26];
	{
		//temporary variables for parsing
		static struct option long_options[] ={
          		/* These options don’t set a flag.
             		We distinguish them by their indices. */
          		{"auth", no_argument, 0, 'a'},
			[...] 
          		{"wtmp", no_argument, 0, 'w'},
			{0,0,0,0}
		};
		//parse the command line arguments
		int option_index = 0;
		while((opt = getopt_long (argc, argv, "aAbdDfhklmsw", long_options, &option_index)) != -1 ){
			switch (opt) {
				case 'a' :
					strncpy(filename, "/var/log/auth.log", sizeof(filename));
					printFile(filename);
					break;
				[...]
				case 'w' :
					strncpy(filename, "/var/log/wtmp",sizeof(filename));
					printFile(filename);
					break;
             			default: 
					printUsage(); 
                 			exit(EXIT_FAILURE);
        		}
		}
	}
	return 1;
}