Extract letters from random input lang C - c

Question

I'm new here. I started software engineering and I have no knowledge of the C language. I did the adding part to the queue, but I cannot separate the foreign values ​​entered. Can you help me with this?
I want to perform the steps in the picture
For example:
Input: E)(=89y-/u665%P
Output: EYUP
My Code
#include <stdio.h>
#include<string.h>
#include <stdlib.h>
#define max 5
int insq(char queue[max][80], int *rear, char data[80])
{
if (*rear == max -1)
return(-1);
else
{
*rear = *rear + 1;
strcpy(queue[*rear], data);
return(1);
}
}
int delq(char queue[max][80], int *front, int *rear, char data[80])
{
if(*front == *rear)
return(-1);
else
{
(*front)++;
strcpy(data, queue[*front]);
return(1);
}
}
int main()
{
char queue[max][80], data[80];
int front, rear, reply;
int ch;
front = rear = -1; //... Initialize a Queue
printf("------------------------------\n");
printf("\tMenu");
printf("\n------------------------------");
printf("\n 1. Insert String in a Queue");
printf("\n 2. Delete String from a Queue");
printf("\n 3. Exit");
printf("\n------------------------------\n");
while(1)
{
printf("Choose operation : ");
scanf("%d", &ch);
switch(ch)
{
case 1 : // insert
printf("\nEnter Something : ");
scanf("%s",data);
reply = insq(queue, &rear, data);
if(reply == -1 )
printf("\nQueue is Full \n");
else
printf("\n'%s' is inserted in queue.\n\n",data);
break;
case 2 : // delete
reply = delq(queue, &front, &rear, data);
if( reply == -1 )
printf("\nQueue is Empty \n");
else
printf("\nDeleted String from Queue is : %s\n", data);
printf("\n");
break;
case 3 : exit(0);
default: printf("Invalid operation \n");
}
}
return 0;
}

Answer 1

You have to parse char by char your string.
Test if it is an char with isalpha then do toupper and happen it to the buffer out. If not test for a blank char and copy it as it, finally just skip char.
Don't forget to add the final \0
/!\ A test if missing to check if you don't overflow out
#include <stdio.h>
#include <ctype.h>
int main() {
const char *p = "E)(=89y-/u665%P";
char out[80];
char *q = out;
while (*p) {
if (isalpha(*p)) {
*q++ = toupper(*p++);
continue;
} else if (isblank(*p)) {
*q++ = *p++;
continue;
}
p++;
}
*q= '\0';
printf("%s\n", out);
return 0;
}
You have in out "EYUP"