Console not waiting for input. (C language) - c

Question

When I execute my code below. It waits for my input for entering a file name. But it doesn't wait for me to enter a filename, but rather just skips it to the _getch() part of it. I'm unable to add a sentence.
Code not working:
#include <stdio.h>
main() {
FILE *fp;
char fnamer[100] = ""; //Storing File Path/Name of Image to Display
printf("\n\nPlease Enter the Full Path of the Image file you want to view: \n");
scanf("%s", &fnamer);
fp = fopen(fnamer, "w");
if (fp == NULL)
{
printf("\n%s\" File NOT FOUND!", fnamer);
}
char c[1000];
printf("Enter a sentence:\n");
gets(c);
fprintf(fp, "%s", c);
fclose(fp);
_getch();
}
Code that works and waits for entering a sentence:
#include <stdio.h>
#include <stdlib.h> /* For exit() function */
int main()
{
char c[1000];
FILE *fptr;
fptr = fopen("program.txt", "w");
if (fptr == NULL){
printf("Error!");
exit(1);
}
printf("Enter a sentence:\n");
gets(c);
fprintf(fptr, "%s", c);
fclose(fptr);
return 0;
}
Both are so similar right there in the end for the prompt asking for a sentence. It doesn't make sense.

Answer 1

you have to flush your input after using scanf.
put a getchar() after every scanf

Answer 2

You are encountering a very common problem when using stdin to receive input, which is after your first scanf call there is a dangling \n character which gets stuck in the buffer from the enter key. To clear this buffer in a portable easy way, add something like
char c;
while ( (c = getchar()) != '\n' && c != EOF ) { }
This simply initializes a character, and then calls get char as many times as needed until it reaches '\n' or 'EOF', which is immediately in your case.
tl;dr :
Your buffer looks like this
hello.txt\n <-- "comes from the enter key"
and when you try to use get(c) it takes the \n as the next enter key.

Answer 3

The rule is never mix scanf and [f]gets. scanf stops before the next unused character, generaly a blank, and the end of line is composed of blank characters.
You could try to put a dummy fgets between the last scanf and the first real fgets. That will ensure that you are now positionned on a beginning of line before reading. Alternatively, you could read everything in lines with fgets, and parse the lines with sscanf. That is what I prefere as soon as I want my input to be line oriented. And always control return values of input functions, it will avoid a progam suddenly going mad without any indication simply because one input gave an ignored error.
And last and not least: never use gets but only fgets, the former is for decades in the hall of shame as the cause of uncountable buffer overflows
Code could become:
#include <stdio.h>
#include <string.h>
main() {
FILE *fp;
char fnamer[100] = ""; //Storing File Path/Name of Image to Display
char c[1000], *ix;
int cr;
printf("\n\nPlease Enter the Full Path of the Image file you want to view: \n");
cr = scanf("%s", &fnamer);
if (cr != 1) {
// process error or abort with message
}
fp = fopen(fnamer, "w");
if (fp == NULL)
{
printf("\n%s\" File NOT FOUND!", fnamer);
return 1; // do not proceed after a fatal error!
}
for(;;) { // read until a newline in input
ix = fgets(c, sizeof(c), stdin);
if (ix == NULL) {
// end of input: abort
}
if (strcspn(c, "\n") < strlen(c)) break;
}
printf("Enter a sentence:\n");
ix = fgets(c, sizeof(c), stdin);
c[strcspn(c, "\n")] = '\0'; // remove end of line to get same data as gets
fprintf(fp, "%s", c);
fclose(fp);
_getch();
}

Answer 4

main() {
FILE *fp;
char fnamer[100]=""; //Storing File Path/Name of Image to Display
printf("\n\nPlease Enter the Full Path of the Image file you want to view: \n");
fgets ( fnamer,100,stdin); //fgets(name, sizeof(name), stdin);
fp=fopen(fnamer,"w");
if(fp==NULL)
{
printf("\n%s\" File NOT FOUND!",fnamer);
getch();
exit(1);
}
}
I Think best way to do,use fgets insted of scanf,Because
fgets() can read any open file, but scanf() only reads standard input(user given).
fgets() reads a line of text from a file; scanf() can be used for that but also handles conversions
from string to built in numeric types