How many this word in the array string - arrays

Question

I want to count how many this word and operator in the string but I try to use strchr and it doesn't work.
#include <stdio.h>
#include <string.h>
#include <ctype.h>
int main()
{
int x,count =0;
char buff[100]="1+2.3(7^8)sin cos + cos sin_e-2x+x2*2!/_x1 sine";
//gets(buff);
strupr(buff);
for (int i = 0; buff[i] != '\0'; i++)
{
if (buff[i] == '+' || buff[i] == '-' || buff[i] == '*' ||
buff[i] == '/' || buff[i] == '^'|| buff[i] == '(')
{
count++;
}
}
char *op2;
int check=0;
char cpysin[100],cpycos[100];
strcpy(cpysin,buff);
strcpy(cpycos,buff);
do
{
if(strchr(cpysin,'SIN')!=0)
{
count++;
strcpy(cpysin,strstr(cpysin,"SIN"));
cpysin[0] = ' ';
cpysin[1] = ' ';
cpysin[2] = ' ';
}
else
{
break;
}
}
while(check==0);
do
{
if(strchr(cpycos,'COS')!=0)
{
count++;
strcpy(cpycos,strstr(cpycos,"COS"));
cpycos[0] = ' ';
cpycos[1] = ' ';
cpycos[2] = ' ';
}
else
{
break;
}
}
while(check==0);
printf("FINAL \n%d",count);
}
I only work when I do it in the loop while trying to find how many sins are in there but it doesn't work when I put cos function on it. Please tell me how to fix this and what if I need to write more functions to find.

Answer 1

strchr(cpysin, 'SIN') is wrong.
Unfortunately the compiler may not give you a warning because 'SIN' can be interpreted as 4 byte integer. The second parameter is supposed to be an integer, but strchr really wants character, it chops it off to 'N'
Just remember that in C you work with single characters 'a' or strings "cos" (or you can come accross wide characters/strings)
Use strstr to find a string. For example, to find "cos":
char* ptr = buff;
char* find = strstr(ptr, "cos");
"1+2.3(7^8)sin cos + cos sin_e-2x+x2*2!/_x1 sine";
---------------^ <- find
find will point to "cos + cos sin_e-2x+x2*2!/_x1 sine"
You can increment ptr and look for the next occurrence of "cos".
Also note, you can declare char buff[] = "...", you don't have to assign the buffer size.
char buff[] = "1+2.3(7^8)sin cos + cos sin_e-2x+x2*2!/_x1 sine";
int count = 0;
const char* ptr = buff;
const char* text = "cos";
//must terminate when ptr reaches '\0' which is at the end of buff
//there is serious problem if we read past it
while(*ptr != '\0')
{
char* find = strstr(ptr, text);
if (find != NULL)
{
printf("update [%s]\n", find);
count++;
ptr = find + strlen(text);
//next search starts after
}
else
{
ptr++;
//next character start at next character
}
}
printf("%s count: %d\n", text, count);