gistfile1.c

// 1回生向け課題のめも

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>

const int DEFAULT_RECORDS_LIST_SIZE = 16;
const int MAX_BUF_SIZE = 256;

typedef struct {
    char code[10];
    char name[40];
    int  price;
} Record;

typedef struct {
    Record **list;
    int    size;
    int    _mem_size;
} Records;

void usage() {
    fprintf(stderr, "usage: kadai1-3 inputfile\n");
}

void error(const char *msg) {
    if (errno) {
        fprintf(stderr, "kadai1-3: %s: %s \n", msg, strerror(errno));
    }
    else {
        fprintf(stderr, "kadai1-3: %s\n", msg);
    }
    usage();
}

Record *create_record(char const *code, char const *name, int price) {
    Record *record = NULL;

    if ( (record = (Record *)(malloc(sizeof(Record)))) == NULL) {
        error("Memory allocation error");
        return NULL;
    }

    strncpy(record->code, code, strlen(code));
    strncpy(record->name, name, strlen(name));
    record->price = price;

    return record;
}

Records *create_records() {
    Records *records;
    records = (Records *)malloc(sizeof(Records));
    if (records == NULL) {
        error("Memory allocation error");
        return NULL;
    };

    records->list = (Record **)calloc(DEFAULT_RECORDS_LIST_SIZE, sizeof(Record *));
    if (records->list == NULL) {
        free(records);
        error("Memory allocation error");
        return NULL;
    }
    records->_mem_size = DEFAULT_RECORDS_LIST_SIZE;
    records->size = 0;

    return records;
}

Record *add_record(Records *records, Record *record) {
    if (!(records->size < records->_mem_size)) {
        // TODO
        // realloc
        // update _mem_size
    }
    records->list[records->size] = record;
    records->size++;

    return record;
}

Record *search_record(Records *records, char *keyword) {
    Record *record;
    int i;
    for (i = 0; i < records->size; i++) {
        record = records->list[i];
        if (strncmp(keyword, record->code, MAX_BUF_SIZE) == 0) {
            return record;
        }
    }
    return NULL;
}

void free_records(Records *records) {
    int i;
    for (i = 0; i < records->size; i++) {
        free(records->list[i]);
    }
    free(records->list);
    free(records);
}

Records *load_records(FILE *i_fp) {
    int i;
    char buf[MAX_BUF_SIZE];
    char code[MAX_BUF_SIZE], name[MAX_BUF_SIZE];
    int price;
    Records *records;
    Record *record;

    records = create_records();
    if (records == NULL) {
        return NULL;
    };

    while ( fgets(buf, MAX_BUF_SIZE, i_fp) != NULL ) {
        i = 0;
        sscanf(buf, "%s%*[ ]%s%*[ ]%d", code, name, &price);

        record = create_record(code, name, price);
        if (records == NULL) {
            free_records(records);
            return NULL;
        };

        record = add_record(records, record);
        if (record == NULL) {
            free_records(records);
            return NULL;
        };
    }

    return records;
}


int main (int argc, char *argv[]) {
    char buf[MAX_BUF_SIZE];
    char *i_filename;
    FILE *i_fp;
    Records *records;
    Record *record;
    errno = 0;
    
    if (argc < 2) {
        error("Too few arugments");
        return EXIT_FAILURE;
    }

    i_filename = argv[1];
    i_fp = fopen(i_filename, "r");
    if( i_fp == NULL) {
        error("File open error");
        return EXIT_FAILURE;
    }
    
    records = load_records(i_fp);
    if (records == NULL) {
        fclose(i_fp);
        return EXIT_FAILURE;
    }

    printf("keyword: ");
    fgets(buf, MAX_BUF_SIZE, stdin);
    buf[strlen(buf) - 1] = '\0';

    record = search_record(records, buf);
    if (record) {
        printf("code:\t%s\n", record->code);
        printf("name:\t%s\n", record->name);
        printf("price:\t%d\n", record->price);
        printf("\n");
    }
    else {
        printf("Not Found.\n");
    }

    free_records(records);
    fclose(i_fp);

    return EXIT_SUCCESS;
}