はじめての C

lang

昨年の 9月から そのままに なってた アドレスブックの code を なんとか 動かせるように してみた。 まちがってる 可能性も あるけど ...

/* addbook.c */

#include <stdio.h>

#include "addbook.h"
int main(int argc, char **argv)

{

    PERSON add_book[MAX_PSN];

    int c;
    long last;

    int record;
    FILE *fp;
    if (argc != 2) {

        fprintf(stderr, "Usage: ./add_book [file]\n");

        exit(1);

    }

    if )((fp = fopen(argv[1], "a+b"))( == NULL) {

        fprintf(stderr, "Can't open %s.\n", argv[1]);

        exit(2);

    }
    puts ("Press [ctrl + d] at the time of finish.");
    for (c = 0; c < MAX_PSN; c++) {

        puts("Enter the name.");

        if (fgets(add_book[c].name, MAX_NAME, stdin) == 0)

            break;

        else {

            puts("Now enter the postal code.");

            fgets(add_book[c].postal_code, MAX_PC, stdin);

            puts("Now enter the address.");

            fgets(add_book[c].address, MAX_ADDR, stdin);

            puts("Now enter the phone number.");

            fgets(add_book[c].phone, MAX_PHN, stdin);

        }

    }

    rewind(fp);
    heapsort(add_book, c);
    fwrite(add_book, sizeof(PERSON), c, fp);
    fclose(fp);
    return 0;

}
/* heapsort.c */

#include <string.h>

#include "addbook.h"
void swap();

void shift();
void heapsort(PERSON a[], int n)

{

    int left, right;
    left = n / 2 + 1;

    right = n;
    while (left > 1)

        shift(a, --left, right);

    while (right > 1) {

        swap(a, 1, right);

        shift(a, 1, --right);

    }

}
void swap(PERSON a[], int i, int j)

{

    PERSON tmp;
    tmp = a[i];

    a[i] = a[j];

    a[j] = tmp;

}
void shift(PERSON a[], int left, int right)

{

    int i, j;

    PERSON tmp;
    i = left;

    j = 2 * i;

    tmp = a[left];
    while (j <= right) {

        if (j < right)

            if (strcmp(a[j].name, a[j + 1].name) < 0)

                j++;

        if (strcmp(tmp.name, a[j].name) >= 0)

            break;

        a[i] = a[j];

        i = j;

        j = 2 * i;

    }

    a[i] = tmp;

}
/* findphn.c */

#include <stdio.h>

#include <string.h>

#include "addbook.h"
#define SEEK_SET 0

#define SEEK_END 2
char * b_search();
int main(int argc, char **argv)

{

    char name[MAX_NAME + 1];

    char *phone;
    long last;

    int record;
    FILE *fp;
    if (argc != 2) {

        fprintf(stderr, "Usage; ./findphn [file]\n");

        exit(1);

    }
    if )((fp = fopen(argv[1], "rb"))( == NULL) {

        fprintf(stderr, "Can't open %s.\n", argv[1]);

        exit(2);

    }
    fseek(fp, 0L, SEEK_END);

    last = ftell(fp);

    record = (int)last / sizeof(PERSON);
    printf("record = %d\n", record);
    puts("Enter the name.");

    fgets(name, MAX_NAME, stdin);
    if )((phone = b_search(name, fp, record))( != NULL)

        fprintf(stdout, "%s <- %s", phone, name);

    else

        fprintf(stdout, "Can't find %s.", name);
    fclose(fp);

}
char *b_search(char *x, FILE *fp, int n)

{

    int low, high, mid;

    static PERSON who;
    low = 0;

    high = n;
    while (low <= high) {

        mid = (low + high) / 2;

        fseek(fp, (mid - 1) * sizeof(PERSON), SEEK_SET);

        fread(&who, sizeof(PERSON), 1, fp);

        if (strcmp(x, who.name) > 0)

            low = mid + 1;

        else

            return who.phone;

    }

    return NULL;

}
/* addbook.h */

#define MAX_NAME 50 + 1

#define MAX_PC 12 + 1

#define MAX_ADDR 100 + 1

#define MAX_PHN 12 + 1

#define MAX_PSN 300 + 1
typedef struct {

    char name[MAX_NAME];

    char postal_code[MAX_PC];

    char address[MAX_ADDR];

    char phone[MAX_PHN];

} PERSON;
void heapsort();
$ cc -c addbook.c heapsort.c

$ cc -o addbook addbook.o heapsort.o

$ cc -o findphn findphn.c
heapsort.c と findphn.c を 説明しようと 思ったが、すでに チカラ 尽きました o ...Lr
(追記) 使用してない 変数と マクロを 削除。