keyword search

#include<stdio.h>

#include<string.h>

#include<ctype.h>

struct key {

    char *word;

    int count;

             };

struct key keytab[] = {

        "auto",0,
        "break",0,
        "case",0,
        "char",0,
        "const",0,
        "continue",0,
        "default",0,
        "do",0,
        "double",0,
        "else",0,
        "enum",0,
        "extern",0,
        "float",0,
        "for",0,
        "goto",0,
        "if",0,
        "int",0,
        "long",0,
        "register",0,
        "return",0,
        "short",0,
        "signed",0,
        "sizeof",0,
        "static",0,
        "struct",0,
        "switch",0,
        "typedef",0,
        "union",0,
        "unsigned",0,
        "void",0,
        "volatile",0,
        "while",0

                    };

#define NKEYS (sizeof keytab / sizeof(struct key))

/*binary search*/

int binsearch (char * word, struct key tab[], int n) {

    int cond;

    int low, high, mid;

    low = 0;

    high = n -1;

    while (low <= high) {

        if ((cond = strcmp(word,tab[mid].word)) < 0)

            high = mid - 1;

        else if (cond > 0)

            low = mid + 1;

        else /*found it*/

            return mid;
                }

    return -1;
                              }

/*linear search*/

int search (char* word, struct key tab[], int n) {

    int i;

    for (i = 0; i < n; ++i) {

        if (strcmp(word,tab[i].word) == 0) {


            return i;
                           }

                 }

    return -1;

                              }


#define BUFFSIZE 100

char BUFF[BUFFSIZE]; /*array for ungetch*/

int bufp = 0; /*buffer position, initialized to zero*/

int getch (void) { /*get a (possibly pushed-back) character*/

    return (bufp > 0) ? BUFF[bufp--] : getchar();


              }


void ungetch (int c) { /* push character back on input */

    if (bufp > BUFFSIZE) {

        printf("ungetch: too many characters\n"); /*if this is filled up*/


                 }

    else {

        BUFF[bufp++] = c;   /*if there's still room*/

          }

              }

/*getword: get next word or character from input and read it into word*/

int getword (char * word, int lim) {

    int c,getch(void);

    void ungetch(int);

    char * w = word;

    while (isspace(c = getch())) {

        ;
                      }
    if (!isalpha(c)) {

        *w = '\0';

        return c;

              }

    for ( ; --lim > 0; w++) {

        if (!isalnum(*w = getch())) {

            ungetch(*w);

            break;

                        }

                }

    *w = '\0';

    return w[0];

                   }


#define MAXWORD 100

/*count C keywords*/

int main (int argc, char * argv[]) {

    int n;

    char word[MAXWORD];

    while (getword(word,MAXWORD) != EOF) {

        printf("I've got past the beginning of the getword loop.\n");

        if(isalpha(word[0])) {

        printf("I'm past the word[0] condition.\n");

            if ((n = binsearch(word,keytab,NKEYS)) >= 0) { //the problem starts here

                printf("past the search condition.\n");

                keytab[n].count++;

                                          }

                      }

                         }

    for (n = 0; n < NKEYS; n++) {

        if (keytab[n].count > 0) {

            printf("%4d %s\n", keytab[n].count,keytab[n].word);

                      }

                    }

    return -1;

                   }