How to append text to a file in C++ and some other tips.

#include <stdlib.h>
#include <stdio.h>
 
int main(void) {
	FILE *f;
	char buf[256];
 
	f = fopen("logfile", "a+");
	if(f) {
		fprintf(f, "This is appended to the file.\n");
	}
	fclose(f);
	return 0;
}

/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/
 
/********************************************************************
* Description:
* Author:  <shoggoth>
* Created at: Wed Jan 19 13:06:21 EST 2011
* Computer: myhost
* System: Linux 2.6.33-ARCH on x86_64
*
* Copyright (c) 2011   All rights reserved.
*
********************************************************************/
 
#include <stdio.h>
#include <time.h>
 
#define format "At this time: %H:%M:%S"
#define text "The user is running this program."
 
int lineofstars (void) {
	int x = 0;
	while (x < 64) {
		printf("*");
		x++;
		if (x == 31) {
			printf("<|>");
		} else if (x == 64) {
			printf("\n-\n");
		}
	}
	return 0;
}
 
int main (int argc, char** argv) {
 
	lineofstars();
 
	char *File;
	char String[60];
	struct tm *ptr;
	time_t tm;
	char length[60];
 
	tm = time(NULL);
	ptr = localtime(&tm);
	strftime(length, 100, format, ptr);
 
	File = "log.txt";
	snprintf(String, 100, "%s, %s\n", length, text);
 
	FILE *f;
	f = fopen (File, "a+");
 
	if (!f) {
		printf("Sorry, I cannot open the file %s.\n", File);
		return 0;
	}
 
	fprintf(f, String);
 
	fflush(stdout);
	fclose(f);
 
	return 0;
}

struct _kern1 {
	char *File;
	int len;
	char Kyo[40];
} *kern1 = (struct _kern1 *) 0x80;
 
void kernel(const char *File, int len)
{
	FILE *f;
	char Kyo[40];
 
	if (len > 10 or len < 2)
		return;
 
	f = fopen(File, "r");
	if(!f) {
		printf ("Sorry, I cannot open: %s.\n", File);
		printf("Please check your permissions with\n"		\
			"your supervisor. The feature may not\n"	\
			"be compiled and\\or enabled in your\n"		\
			"kernel version. Or a scsi device, eg,\n"	\
			"a USB drive may not be attached.\n");
		return;
	} else {
/* Based on sample code from:
 * www.koders.com/c/fid84CFEFBF311605F963CB04E0F84A2F52A8120F33.aspx
 * Specifically the section on parsing the /proc/version.
 */
		while (feof(f) != 1) {
			fgets(Kyo, len, f);
/*
 * This function is fast, owing to this i feel. especially with gcc 
 * 4.3.2 & glibc 2.5+. it is faster than using: printf (Kyo);
 */
			fprintf (stdout, "%s", Kyo);
			fflush(stdout);
		}
	}
	fclose(f);
}

	char* myarg1 = argv[1];
 
	if (!argc or !myarg1) {
		print_menu();
	}

	if (argc > 1 and strncmp(argv[1], "4", BUF) == 0) {
		printf("\t\tSound Card information.\n");
 
		kernel("/proc/asound/cards", 3);
	}