Program:
#include<string.h>
#include<conio.h>
#include<ctype.h>
#include<stdio.h>
void main()
{
FILE *f1;
char c,str[10];
int lineno=1,num=0,i=0;
clrscr();
printf("\nEnter the c program\n");
f1=fopen("input.txt","w");
while((c=getchar())!=EOF)
putc(c,f1);
fclose(f1);
f1=fopen("input.txt","r");
while((c=getc(f1))!=EOF) // TO READ THE GIVEN FILE
{
if(isdigit(c)) // TO RECOGNIZE NUMBERS
{
num=c-48;
c=getc(f1);
while(isdigit(c))
{
num=num*10+(c-48);
c=getc(f1);
}
printf("%d is a number \n",num);
ungetc(c,f1);
}
else if(isalpha(c)) // TO RECOGNIZE KEYWORDS AND IDENTIFIERS
{
str[i++]=c;
c=getc(f1);
while(isdigit(c)||isalpha(c)||c=='_'||c=='$')
{
str[i++]=c;
c=getc(f1);
}
str[i++]='\0';
if(strcmp("for",str)==0||strcmp("while",str)==0||strcmp("do",str)==0||
strcmp("int",str)==0||strcmp("float",str)==0||strcmp("char",str)==0||
strcmp("double",str)==0||strcmp("static",str)==0||
strcmp("switch",str)==0||strcmp("case",str)==0) // TYPE 32 KEYWORDS
printf("%s is a keyword\n",str);
else
printf("%s is a identifier\n",str);
ungetc(c,f1);
i=0;
}
else if(c==' '||c=='\t') // TO IGNORE THE SPACE
printf("\n");
else if(c=='\n') // TO COUNT LINE NUMBER
lineno++;
else // TO FIND SPECIAL SYMBOL
printf("%c is a special symbol\n",c);
}
printf("Total no. of lines are: %d\n",lineno);
fclose(f1);
getch();
}
OUTPUT
Enter the c program
int main()
{
int a=10,20;
charch;
float f;
}^Z
The numbers in the program are: 10 20
The keywords and identifiersare:
int is a keyword
main is an identifier
int is a keyword
a is an identifier
char is a keyword
ch is an identifier
float is a keyword
f is an identifier
Special characters are ( ) { = , ; ; ; }
Total no. of lines are:5
