C - 小さなツール - 1つのことだけをうまくやる - ファイルの読み書き, 独自のデータストリーム

開発環境

Head First C ―頭とからだで覚えるCの基本、 David Griffiths(著)、 Dawn Griffiths(著)、中田秀基(監修)、木下哲也(翻訳)、 O’Reilly Media)の3章(小さなツール - 1つのことだけをうまくやる)、p.133(プールパズル)の解答を求めてみる。

Makefile

all: main.c
	cc main.c && ./a.out

コード

main.c

#include <stdio.h>
#include <string.h>

int main()
{
    char line[80];
    FILE *in = fopen("spooky.csv", "r");
    FILE *file1 = fopen("ufos.csv", "w");
    FILE *file2 = fopen("disappearances.csv", "w");
    FILE *file3 = fopen("others.csv", "w");
    while (fscanf(in, "%79[^\n]\n", line) == 1)
    {
        if (strstr(line, "UFO"))
        {
            fprintf(file1, "%s\n", line);
        }
        else if (strstr(line, "Disappearance"))
        {
            fprintf(file2, "%s\n", line);
        }
        else
        {
            fprintf(file3, "%s\n", line);
        }
    }
    fclose(in);
    fclose(file1);
    fclose(file2);
    fclose(file3);
}

CSVファイル

spooky.csv

 42.363327,-71.097588,Speed = 23,Type="UFO"
 42.363182,-71.095833,Speed = 22,Type="UFO"
 42.362965,-71.093201,Speed = 18,Type="UFO"
 42.362747,-71.090569,Speed = 23,Type="UFO"
 42.362602,-71.088814,Speed = 19,Type="UFO"
 42.362675,-71.089691,Speed = 14,Type="Elvis"
 42.363400,-71.098465,Speed = 21,Type="Mermaid"
 42.363255,-71.096710,Speed = 17,Type="Disappearance"
 42.363110,-71.094955,Speed = 14,Type="Goatsucker"
 42.363037,-71.094078,Speed = 16,Type="Disappearance"
 42.362892,-71.092323,Speed = 22,Type="Giant octopus"
 42.362820,-71.091446,Speed = 17,Type="Disappearance"
 42.362530,-71.087936,Speed = 16,Type="Disappearance"
 42.362457,-71.087059,Speed = 16,Type="Disappearance"
 42.362385,-71.086182,Speed = 21,Type="Yeti"

CSVファイル

ufos.csv

 42.363327,-71.097588,Speed = 23,Type="UFO"
42.363182,-71.095833,Speed = 22,Type="UFO"
42.362965,-71.093201,Speed = 18,Type="UFO"
42.362747,-71.090569,Speed = 23,Type="UFO"
42.362602,-71.088814,Speed = 19,Type="UFO"

CSVファイル

disappearances.csv

42.363255,-71.096710,Speed = 17,Type="Disappearance"
42.363037,-71.094078,Speed = 16,Type="Disappearance"
42.362820,-71.091446,Speed = 17,Type="Disappearance"
42.362530,-71.087936,Speed = 16,Type="Disappearance"
42.362457,-71.087059,Speed = 16,Type="Disappearance"

others.csv

42.362675,-71.089691,Speed = 14,Type="Elvis"
42.363400,-71.098465,Speed = 21,Type="Mermaid"
42.363110,-71.094955,Speed = 14,Type="Goatsucker"
42.362892,-71.092323,Speed = 22,Type="Giant octopus"
42.362385,-71.086182,Speed = 21,Type="Yeti"

入出力結果(Terminal, Zsh)

% make
cc main.c && ./a.out
%