notes.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <sys/stat.h>

#define MAX 65535
// https://github.com/OsandaMalith
void banner() {
	static const char *banner = 
	"\t+------------------------+\n"
	"\t+---Simple Note Taker----+\n"
	"\t+-Coded by @OsandaMalith-+\n"
	"\t+------------------------+\n\n";
	
	for(banner; *banner; ++banner) fprintf(stdout, "%c", *banner);
}

void fatal(char *msg) {
   char err_msg[100];
   strcpy(err_msg, "[!!] Fatal Error ");
   strncat(err_msg, msg, 75);
   perror(err_msg);
   exit(-1);
}

void *ecalloc(unsigned int size) {
   void *ptr = calloc(size, sizeof(char));
   if(!ptr) fatal("in emalloc() on memory allocation");
   return ptr;
}

void usage(char *appname) {
   printf("Usage: %s <path name> <data to add>\n", appname);
   exit(0);
}

int main (int argc, char *argv[]) {
	banner();
	
    	char *path = (char *) ecalloc(MAX), 
	     *data = (char *) ecalloc(MAX);
	
	if(argc < 2) usage(argv[0]);
	
	strcpy(path, argv[1]);  
	strcpy(data, argv[2]);
	
	printf("[iNFO] path -> 0x%p: \'%s\'\n", path, path);
	printf("[iNFO] data -> 0x%p: \'%s\'\n", data, data);
    
	strncat(data, "\n", 1); 
        
        int fd = open(path, O_WRONLY|O_CREAT|O_APPEND, S_IRUSR|S_IWUSR);
    
        if(fd == -1) fatal("in main() while opening file");

	printf("[iNFO] File Descriptor is %d\n", fd);
	
	if(write(fd, data, strlen(data)) == -1) 
		fatal("in main() while writing buffer to file");
	
        if(close(fd) == -1) fatal("in main() while closing file");
	
	return 0;
}