Tokenizer in C

#include<stdio.h>
#include<conio.h>
void main()
{
   FILE *in,*out;
   char c;
   short flag=0,i=0;
   const char *outPath="C:\\tc\\bin\\out.txt";
   clrscr();
   in = fopen("C:\\tc\\bin\\src.txt","r");
   if(in==NULL)
    {
     printf("Can't Open the src file");
         exit(0);
    }
   out = fopen(outPath,"w");
   while(!feof(in))
    {
         c=fgetc(in);
         if(c==' ' || c=='\n')
          {
           if(flag==0)
            {
                if (i!=0)
                        fputc('\n',out);
                flag=1;
            }
          }
         else if(c==',' || c=='+' || c=='-' || c=='*' || c=='(' || c==')'
                   || c=='[' || c==']' || c=='{' || c=='}'|| c==';' || c=='='
                   || c=='"' || c=='\''|| c=='/' || c=='^' || c=='%' || c=='!'
                   || c=='|' || c=='#' || c=='<' || c=='>')
          {
            if(flag==0)
                 {
                  if(i!=0)
                    fputc('\n',out); // flag=1;
                 }
            fputc(c,out);
            fputc('\n',out);
            flag=1;
          }
         else{
            fputc(c,out);
            flag=0;
          }
         i++;
    }
    fclose(in);
    fclose(out);
    printf("Output file generated--at loc:\n\r");
    puts(outPath);
    getch();
}
//TOKEN GENERATION
#include<stdio.h>
#include<conio.h>
 
short isOp(char st[]);
short isDelim(char st[]);
short isIden(char st[]);
short isKeywrd(char st[]);
short isPrepDire(char st[]);
short isInteger(char st[]);
 
int main()
 {
   FILE *in,*out;
   char str[63];
   short i;
   clrscr();
   in = fopen("C:\\tc\\bin\\out.txt","r");
   if(in==NULL)
    {
         printf("Can't Open the file");
    }
   out = fopen("C:\\tc\\bin\\outTok.txt","w");
   while(!feof(in))
    {
         fgets(str,63,in);
           if(isOp(str))
            {
                 fputc(str[0],out);
                 fprintf(out," | Operator");
                 fputc('\n',out);
            }
           else if(isDelim(str))
            {
                 fputc(str[0],out);
                 fprintf(out," | Delimiter");
                 fputc('\n',out);
            }
            else if (isKeywrd(str))
                {
                  for(i=0;str[i]!='\n';i++);
                        str[i]='\0';
                  fputs(str,out);
                  fprintf(out," | Keyword");
                  fputc('\n',out);
                }
            else if(isPrepDire(str))
                {
                   for(i=0;str[i]!='\n';i++);
                        str[i]='\0';
                   fputs(str,out);
                   fprintf(out," | Preprocessor Directive");
                   fputc('\n',out);
                }
 
            else if(isIden(str))
                {
                  for(i=0;str[i]!='\n';i++);
                        str[i]='\0';
                  fputs(str,out);
                  fprintf(out," | Identifier");
                  fputc('\n',out);
                }
            else if(isInteger(str))
            {
                 for(i=0;str[i]!='\n';i++);
                        str[i]='\0';
                  fputs(str,out);
                  fprintf(out," | Constant Number");
                  fputc('\n',out);
 
            }
            else if(str[0]=='#')
                {
                    for(i=0;str[i]!='\n';i++);
                        str[i]='\0';
                        fputs(str,out);
                    fprintf(out," | Hash directive");
                        fputc('\n',out);
                }
           else     // if Invalid
                {
                  for(i=0;str[i]!='\n';i++);
                        str[i]='\0';
                  fprintf(out,str);
                  fprintf(out," | Invalid");
                  fputc('\n',out);
                }
    }
    fclose(in);
    fclose(out);
    printf("Output file generated--\n\r");
    getch();
    return 0;
 }
short isOp(char st[])
 {
    if((st[1]=='\n') && (st[0]=='+' || st[0]=='-' || st[0]=='/' || st[0]=='*' || st[0]=='%' || st[0]=='^' || st[0]=='='))
         return 1;
   else
         return 0;
 }
short isInteger(char st[])
 {
 int i;
   for(i=0;st[i]!='\n';i++)
    {
         if(isdigit(st[i]))
          {
            return 1;
          }
        }
         return 0;
 }
short isDelim(char st[])
 {
   if(st[0]==';' || st[0]==',' || st[0]=='(' || st[0]==')' || st[0]=='[' || st[0]==']' || st[0]=='{' || st[0]=='}' || st[0]=='{' || st[0]=='}' || st[0]=='<' || st[0]=='>' || st[0]=='"' || st[0]=='\'')
         return 1;
   else
         return 0;
 }
short isIden(char st[])
 {
   int i=0,flag=0;
 
   if(st[0]=='_' || (st[0]>='A' && st[0]<='Z') || (st[0]>='a' && st[0]<='z')) // Checks for the 1st char
        {
          if(st[1]=='\n')
                return 1;
 
          for(i=1;st[i]!='\n';i++)
           {
                if((st[i]>='A' && st[i]<='Z') || (st[i]>='a' && st[i]<='z') || (st[i]>='0' && st[i]<='9') || st[i]=='_')
                    flag=1;
                else
                  {
                    flag=0;
                    break;
                  }
           }
        }
    if(flag==1)
          return 1;
    else
          return 0;
 }
short isKeywrd(char st[])
 {
   char keywrd[15];
   short i,flag=0;
   FILE *kWrd;
   kWrd = fopen("C:\\tc\\bin\\KEYWORDL.txt","r"); // Points to the file containing the list of keywords
    if(kWrd == NULL)
        {
          printf("\nCan't Open the file Keywordlist....");
           {
                getch();
                exit(0);
           }
        }
   while(!feof(kWrd))
    {
          fgets(keywrd,15,kWrd);
           for(i=0;keywrd[i]!='\n';i++)
            {
                 if(st[i]==keywrd[i])
                        flag=1;
                 else
                   {
                        flag=0;
                        break;
                   }
            }
          if(flag==1)
           {
                fclose(kWrd);
                return 1;
           }
    }
                fclose(kWrd);
          return 0;
 }
 short isPrepDire(char st[])
 {
    char direc[15];
    short i,flag=0;
    FILE *direct;
   direct = fopen("C:\\tc\\bin\\direcs.txt","r"); // Points to the file containing the list of keywords
    if(direct == NULL)
        {
          printf("\nCan't Open the file directiv....");
          getch();
          exit(0);
        }
   while(!feof(direct))
    {
          fgets(direc,15,direct);
           for(i=0;direc[i]!='\n';i++)
            {
                 if(st[i]==direc[i])
                        flag=1;
                 else
                   {
                        flag=0;
                        break;
                   }
            }
          if(flag==1)
           {
                fclose(direct);
                return 1;
           }
    }
         fclose(direct);
         return 0;
}