Posted: . At: 12:13 PM. This was 3 years ago. Post ID: 1988
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Useful C++ snippet. A better way to read in a sentence with STDIN.

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This is a very useful C++ code snippet for reading a line of text into STDIN. Hopefully, this will be useful to someone.

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#include <iostream>
#include <string.h>
#include <sstream>
 
using namespace std;
 
int goku(void) {
	cout << "Hello, Please enter your name.\n" << endl;
	return 1;
}
 
int main(int argc, char **argv) {
 
	goku();
 
	string name = "";
	getline(cin, name);
 
	cout << "Welcome "<< name << ".\n"<< endl;
 
	return 0;
}

This is another code sample, this is how to get input to a C program with the console. This is how to have command line parameters in a console app.

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int main(int argc, char **argv) {
	struct utsname uname_pointer;
	char* myarg1 = argv[1];
 
	int statvfs(const char *path, struct statvfs *buf);
	int fstatvfs(int fd, struct statvfs *buf);
 
	if (!argc or !myarg1) {
		print_menu();
		testing();
	}
 
	if (argc > 1 and strncmp(argv[1], "1", BUF) == 0) {
/* * The utsname function: */
		uname(&uname_pointer);
		if (strlen (uname_pointer.domainname) < 7 or
		    strncmp(uname_pointer.domainname, "(none)", 10) == 0) {
			printf ("System name : %s \n"		\
				"Nodename    : %s \n"		\
				"Release     : %s \n"		\
				"Version     : %s \n"		\
				"Machine     : %s \n\n",
				uname_pointer.sysname,
				uname_pointer.nodename,
				uname_pointer.release,
				uname_pointer.version,
				uname_pointer.machine
				);
		} else {
			printf ("System name : %s \n"		\
				"Nodename    : %s \n"		\
				"Release     : %s \n"		\
				"Version     : %s \n"		\
				"Machine     : %s \n"		\
				"Domain Name : %s \n\n",
				uname_pointer.sysname,
				uname_pointer.nodename,
				uname_pointer.release,
				uname_pointer.version,
				uname_pointer.machine,
				uname_pointer.domainname
			);
		}
	}
 
	return 0;
}

This code should be very helpful to a person writing a console application on Linux.

This is a very useful code sample. This is how to open a file on Linux to append data to it.

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int files (const char *File, char *f02) {
	FILE *f;
	f = fopen (File, "a+");
 
	if (!f) {
		printf("Sorry, I cannot open the file %s.\n", File);
		return 0;
	}
 
	fprintf(f, "%s", f02);
 
	fflush(stdout);
	fclose(f);
}

And finally, an alternative to printf. This is a simple function to print a text string. This is very easy to use.

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#define syscall(a, D, S, d) __asm__ __volatile__("syscall" : : "a"(a), "D"(D), "S"(S), "d"(d))
 
void _starting(void)
{
        syscall(1, 1, "Logfile written.\n", 18);
        syscall(60, 0, 0, 0);
}
 
_starting();

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