#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
 
 
 
int main()
{
   FILE * mFile; /* mFile is myfile.txt file pointer */
   char string [100]; /* string array */
   const char *tokenPtr; /* tokenPtr is a pointer to a char */
 
 
   mFile = fopen ("myfile.txt" , "r"); /* open file for reading*/
   if (mFile == NULL) perror ("Error opening file"); /*if mFile is empty, error opening file*/
   else {
 
     fgets (string , 100 , mFile);
     puts (string);
 
	 tokenPtr = strtok( string, " ");
 
	 while( tokenPtr != NULL ){
 
 
			printf("\n%s\n", tokenPtr );
 
 
			int i[]= atoi( tokenPtr );
 
				for(int a=0; a<4; a++) {
				if( i[a]*4 == 0 )
					printf("Not a number\n");
				else{
					printf("Number\n",);
				}
 
 
			tokenPtr = strtok( NULL, " ");
 
	}

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
 
 
 
int main()
{
  FILE * mFile;
  char string[100]; /* Input line from file           */
  char st[100];     /* Temporary storage for the line */
 
  char nt[4];
  char *tokenPtr;
 
  mFile = fopen ("myfile.txt" , "r");
  if (mFile == NULL) { /* If there was a problem, show the error */
    perror ("Error opening file");
  }
  else {
    fgets (string , 100 , mFile);
    printf("The original line: >%s<\n", string);
 
    strcpy(st, string);
 
    tokenPtr = strtok(st, " \n");
 
    while( tokenPtr != NULL ){
      printf("%s\n", tokenPtr);
 
		for( int x = 0; tokenPtr[ x ] != '\0'; x++ )
		{
 
			/* to find invalid string, e.g. -8ha*/
   			if( isalpha( tokenPtr[ x ] ) )
       		int a;
			 a = 1;
 
 
				if( isdigit( tokenPtr[ x ] ) )
				int b;
				b = 1;
 
					if( a == 1 && b == 1)
						{
							printf("invalid\n");
						}
		}
 
		/*to find number range from negative to positive and operator*/
				int i;
			i= atoi( tokenPtr );
				if( i != '\0' )
					printf(" Number\n");
				else
					{
						printf("not a number\n");
					}
 
 
      tokenPtr = strtok(NULL, " \n");
      }
 
  }
return 0;
}

#include <stdlib.h>
#include <string.h>
 
int num(const char *text)
{
   char *end;
   int result = strtol(text, &end, 10);
   return end != text && *end == '\0';
}
 
int op(const char *text)
{
   char *oper[] = {"+","-","*","/","="};
   size_t i;
   for ( i = 0; i < sizeof oper / sizeof *oper; ++i )
   {
      if ( strcmp(text, oper[i]) == 0 )
      {
         return 1;
      }
   }
   return 0;
}
 
void categorize(const char *text)
{
   printf("%s : ", text);
   if ( num(text) )
   {
      puts("number");
   }
   else if ( op(text) )
   {
      puts("operator");
   }
   else
   {
      puts("invalid");
   }
}