17.c

#include<string.h>
#include<ctype.h>
#include<stdio.h>
void keyword(char str[10])
{
	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
	)
		printf("\n%s is a keyword", str);

	else
		printf("\n%s is an identifier", str);
}
main()
{
	FILE *f1, *f2, *f3;
	char c, str[10], st1[10];
	int num[100], lineno = 0, tokenvalue = 0, i = 0, j = 0, k = 0;
	
	printf("\nEnter the path of the file: ");
	gets(st1);
	f1 = fopen(st1, "r");
	/*
	while((c = getchar())! = EOF)
		putc(c, f1);
	*/

	f2 = fopen("identifier", "w");
	f3 = fopen("specialchar", "w");
	while((c = getc(f1)) != EOF)
	{
		if(isdigit(c))
		{
			tokenvalue = c-'0';
			c = getc(f1);
			while(isdigit(c))
			{
				tokenvalue *= 10+c-'0';
				c = getc(f1);
			}

			num[i++] = tokenvalue;
			ungetc(c, f1);
		}

		else if(isalpha(c))
		{
			putc(c, f2);c = getc(f1);
			while(isdigit(c)||isalpha(c)||c == '_'||c == '$')
			{
				putc(c, f2);
				c = getc(f1);
			}
			
			putc(' ', f2);
			ungetc(c, f1);
		}

		else if(c == ' '||c == '\t')
			printf(" ");
		
		else if(c == '\n')
			lineno++;
		
		else putc(c, f3);
	}

	fclose(f2); fclose(f3); fclose(f1);

	printf("\nThe numbers in the program are: ");
	for(j = 0;j<i;j++)
		printf("%d", num[j]);
	printf("\n");

	f2 = fopen("identifier", "r");
	k = 0;
	printf("\nThe keywords and identifiers are: ");
	while((c = getc(f2)) != EOF)
	{
		if(c != ' ')
			str[k++] = c;
		else
		{
			str[k] = '\0';
			keyword(str);
			k = 0;
		}
	}
	fclose(f2);

	f3 = fopen("specialchar", "r");
	printf("\nThe special characters are");
	while((c = getc(f3)) != EOF)
		printf("%c", c); printf("\n");
	fclose(f3);

	printf("\nTotal no. of lines are: %d", lineno);
}